LIGHT-EMITTING DEVICE INCLUDING ORGANOMETALLIC COMPOUND, ELECTRONIC APPARATUS INCLUDING THE LIGHT-EMITTING DEVICE, AND THE ORGANOMETALLIC COMPOUND

Abstract

A light-emitting device including an organometallic compound represented by Formula 1, an electronic apparatus including the light-emitting device, and the organometallic compound represented by Formula 1, as described herein, are provided.

##STR00001##

Claims

1. A light-emitting device comprising: a first electrode; a second electrode opposite to the first electrode; an interlayer between the first electrode and the second electrode and comprising an emission layer; and an organometallic compound represented by Formula 1: ##STR00215## wherein, in Formula 1, M is platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh), ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm), X.sub.1 to X.sub.4 are each independently C or N, ring CY.sub.1 to ring CY.sub.4 are each independently a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, and ring CY.sub.3 comprises a moiety represented by Formula 1A, L.sub.1 to L.sub.3 are each independently a single bond, *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)*, *C(R.sub.1a)*, *C(R.sub.1a)C(R.sub.1b)*, *C[C(R.sub.1a)(R.sub.1b)]*, *C(O),* *C(S)*, *CC*, * B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(R.sub.1a)*, *Al(R.sub.1a)*, *Si(R.sub.1a)(R.sub.1b)*, *P(O)(R.sub.1a)*, *S*S(O)*, *S(O).sub.2*, or *Ge(R.sub.1a)(R.sub.1b)*, * and * each indicate a binding site to a neighboring atom, n1 to n3 are each independently an integer from 1 to 10, R.sub.1 to R.sub.4, R.sub.1a, and R.sub.1b are each independently hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), a1 to a4 are each independently an integer from 1 to 20, and two or more adjacent groups selected from among, each R.sub.1, R.sub.11, each R.sub.2, each R.sub.3, each R.sub.4, R.sub.1a, and R.sub.1b, are optionally bonded to each other to form a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, and wherein, in Formula 1A, ring CY.sub.31 and ring CY.sub.32 are each independently a C.sub.1-C.sub.30 heterocyclic group, m is an integer from 1 to 5, R.sub.10a is: deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, or a C.sub.1-C.sub.60 alkoxy group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.11)(Q.sub.12)(Q.sub.13), N(Q.sub.11)(Q.sub.12), B(Q.sub.11)(Q.sub.12), C(O)(Q.sub.11), S(O).sub.2(Q.sub.11), P(O)(Q.sub.11)(Q.sub.12), or any combination thereof; a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.21)(Q.sub.22)(Q.sub.23), N(Q.sub.21)(Q.sub.22), B(Q.sub.21)(Q.sub.22), C(O)(Q.sub.21), S(O).sub.2(Q.sub.21), P(O)(Q.sub.21)(Q.sub.22), or any combination thereof; or O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), or P(O)(Q.sub.31)(Q.sub.32), and Q.sub.1 to Q.sub.3, Q.sub.11 to Q.sub.13, Q.sub.21 to Q.sub.23, and Q.sub.31 to Q.sub.33 are each independently hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group, or a C.sub.1-C.sub.60 heterocyclic group; each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof; a C.sub.7-C.sub.60 arylakyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group.

2. The light-emitting device of claim 1, wherein the emission layer comprises a host and a dopant, and the dopant comprises the organometallic compound.

3. The light-emitting device of claim 1, further comprising a second compound comprising at least one electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group, a third compound comprising a group represented by Formula 3, a fourth compound capable of emitting delayed fluorescence, or any combination thereof, wherein the organometallic compound, the second compound, the third compound, and the fourth compound are different from each other: ##STR00216## wherein, in Formula 3, ring CY.sub.71 and ring CY.sub.72 are each independently a electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group, X.sub.71 is a single bond, or a linking group comprising O, S, N, B, C, Si, or any combination thereof, and * indicates a binding site to any atom in the third compound not comprising Formula 3.

4. The light-emitting device of claim 3, wherein the second compound comprises a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or any combination thereof, and the fourth compound comprises at least one cyclic group comprising both boron (B) and nitrogen (N) as ring-forming atoms.

5. The light-emitting device of claim 3, wherein the emission layer comprises: i) the organometallic compound; and ii) the second compound, the third compound, the fourth compound, or any combination thereof, and the emission layer is configured to emit blue light.

6. An electronic apparatus comprising the light-emitting device of claim 1.

7. The electronic apparatus of claim 6, further comprising a thin-film transistor, wherein the thin-film transistor comprises a source electrode and a drain electrode, and the first electrode of the light-emitting device is electrically connected to the source electrode or the drain electrode of the thin-film transistor.

8. The electronic apparatus of claim 6, further comprising a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.

9. An electronic equipment comprising the light-emitting device of claim 1.

10. The electronic equipment of claim 9, wherein the electronic equipment is at least one selected from among a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, an indoor or outdoor light and/or light for signal, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a portable phone, a tablet personal computer, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro display, a three-dimensional (3D) display, a virtual reality or augmented reality display, a vehicle, a video wall with multiple displays tiled together, a theater or stadium screen, a phototherapy device, a signboard, and combinations thereof.

11. An organometallic compound represented by Formula 1: ##STR00217## wherein, in Formula 1, M is platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh), ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm), X.sub.1 to X.sub.4 are each independently C or N, ring CY.sub.1 to ring CY.sub.4 are each independently a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, and ring CY3 comprises a moiety represented by Formula 1A, L.sub.1 to L.sub.3 are each independently a single bond, *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)*, *C(R.sub.1a)*, *C(R.sub.1a)C(R.sub.1b)*, *C[C(R.sub.1a)(R.sub.1b)]*, *C(O), *C(S)*, *CC*, *B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(R.sub.1a)*, *Al(R.sub.1a)*, *Si(R.sub.1a)(R.sub.1b)*, *P(O)(R.sub.1a)*, *S*S(O)*, *S(O).sub.2*, or *Ge(R.sub.1a)(R.sub.1b)*, * and * each indicate a binding site to a neighboring atom, n1 to n3 are each independently an integer from 1 to 10, R.sub.1 to R.sub.4, R.sub.1a, and R.sub.1b are each independently hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), a1 to a4 are each independently an integer from 1 to 20, and two or more adjacent groups of selected from among, each R.sub.1, R.sub.11, each R.sub.2, each R.sub.3, each R.sub.4, R.sub.1a, and R.sub.1b, are optionally bonded to each other to form a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, and wherein, in Formula 1A, ring CY.sub.31 and ring CY.sub.32 are each independently a C.sub.1-C.sub.30 heterocyclic group, m is an integer from 1 to 5, R.sub.10a is: deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, or a C.sub.1-C.sub.60 alkoxy group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.11)(Q.sub.12)(Q.sub.13), N(Q.sub.11)(Q.sub.12), B(Q.sub.11)(Q.sub.12), C(O)(Q.sub.11), S(O).sub.2(Q.sub.11), P(O)(Q.sub.11)(Q.sub.12), or any combination thereof; a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.21)(Q.sub.22)(Q.sub.23), N(Q.sub.21)(Q.sub.22), B(Q.sub.21)(Q.sub.22), C(O)(Q.sub.21), S(O).sub.2(Q.sub.21), P(O)(Q.sub.21)(Q.sub.22), or any combination thereof; or O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), or P(O)(Q.sub.31)(Q.sub.32), and Q.sub.1 to Q.sub.3, Q.sub.11 to Q.sub.13, Q.sub.21 to Q.sub.23, and Q.sub.31 to Q.sub.33 are each independently hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group; each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof; a C.sub.7-C.sub.60 arylakyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group.

12. The organometallic compound of claim 11, wherein M is platinum (Pt), palladium (Pd), or gold (Au).

13. The organometallic compound of claim 11, wherein X.sub.1, X.sub.2, and X.sub.3 are each C, and X.sub.4 is N, a bond between X.sub.1 and M and a bond between X.sub.4 and M are each a coordinate bond, and a bond between X.sub.2 and M and a bond between X.sub.3 and M are each a covalent bond.

14. The organometallic compound of claim 11, wherein ring CY1, ring CY2, and ring CY4 are each independently a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silol group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilol group, a dibenzosilol group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilol group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a dibenzoxacillin group, a dibenzothiacillin group, a dibenzodihydroazacillin group, a dibenzodihydrodicillin group, a dibenzodihydrocillin group, a dibenzodioxine group, a dibenzoxathiin group, a dibenzoxazine group, a dibenzopyran group, a dibenzodithiin group, a dibenzothiazine group, a dibenzothiopyran group, a dibenzocyclohexadiene group, a dibenzodihydropyridine group, or a dibenzodihydropyrazine group.

15. The organometallic compound of claim 11, wherein ring CY.sub.31 and ring CY.sub.32 are each independently dihydrobenzimidazole, tetrahydroquinazoline, tetrahydroquinoxaline, dihydrobenzooxadiazine, dihydrobenzothiadiazine, tetrahydrobenzotriazine, tetrahydrobenzodiazepine, tetrahydrobenzooxadiazepine, dihydrobenzodioxadiazepine, tetrahydrobenzothiadiazepine, dihydrobenzodithiadiazepine, tetrahydrobenzotriazepine, tetrahydrobenzotetrazepine, tetrahydrobenzooxatriazepine, tetrahydrobenzothiatriazepine, dihydrobenzooxathiadiazepine, dihydronaphthoimidazole, tetrahydrobenzoquinazoline, tetrahydrobenzoquinoxaline, dihydronaphthooxadiazine, dihydronaphthothiadiazine, tetrahydronaphthotriazine, tetrahydronaphthodiazepine, tetrahydronaphthooxadiazepine, dihydronaphthodioxadiazepine, tetrahydronaphthothiadiazepine, dihydronaphthodithiadiazepine, tetrahydronaphthotriazepine, tetrahydronaphthotetrazepine, tetrahydronaphthooxatriazepine, tetrahydronaphthothiatriazepine, dihydronaphthooxayhiadiazepine, dihydroimidazopyridine, tetrahydropyridopyrimidine, tetrahydropyridopyrazine, dihydropyridooxadiazine, dihydropyridothiadiazine, tetrahydropyridotriazine, tetrahydropyridodiazepine, tetrahydropyridooxadiazepine, dihydropyridodioxadiazepine, tetrahydropyridothiadiazepine, dihydropyridodithiadiazepine, tetrahydropyridotriazepine, tetrahydropyridotetrazepine, tetrahydropyridooxatriazepine, tetrahydropyridothiatriazepine, dihydropyridooxathiadiazepine, dihydropurine, tetrahydropyrimidopyrimidine, tetrahydropteridine, dihydropyrimidooxadiazine, dihydropyrimidothiadiazine, tetrahydropyrimidoa triazine, tetrahydropyrimidodiazepine, tetrahydrpyrimidooxadiazepine, dihydropyrimidodioxadiazepine, tetrahydropyrimidothiadiazepine, dihydropyrimidodithiadiazepine, tetrahydropyrimidotriazepine, tetrahydropyrimidotetrazepine, tetrahydropyrimidooxatriazepine, tetrahydropyrimidothiatriazepine, dihydropyrimidooxathiadiazepine, dihydroan imidazopyridazine, tetrahydropyrimidopyridazine, tetrahydropyridazinopyrazine, dihydropyridazinooxadiazine, dihydropyridazinothiadiazine, tetrahydropyridazinotriazine, tetrahydropyridazinodiazepine, tetrahydropyridazinooxadiazepine, dihydropyridazinodioxadiazepine, tetrahydropyridazinothiadiazepine, dihydropyridazinodithiadiazepine, tetrahydropyridazinotriazepine, tetrahydropyridazinotetrazepine, tetrahydropyridazinooxatriazepine, tetrahydropyridazinothiatriazepine, dihydropyridazinooxathiadiazepine, dihydroimidazopyrazine, tetrahydropyrazinopyrazine, dihydropyrazinooxadiazine, dihydropyrazinothiadiazine, tetrahydropyrazinotriazine, tetrahydropyrazinodiazepine, tetrahydropyrazinooxadiazepine, dihydropyrazinodioxadiazepine, tetrahydropyrazinothiadiazepine, dihydropyrazinodithiadiazepine, tetrahydropyrazinotriazepine, tetrahydropyrazinotetrazepine, tetrahydropyrazinooxatriazepine, tetrahydropyrazinothiatriazepine, dihydropyrazinooxathiadiazepine, dihydroimidazoquinoline, tetrahydropyrimidoquinoline, tetrahydropyrazinoquinoline, dihydrooxadiazinoquinoline, dihydrothiadiazinoquinoline, tetrahydrotrianinoquinoline, tetrahydrodiazepinoquinoline, tetrahydrooxadiazepinoquinoline, dihydrodioxadiazepinoquinoline, tetrahydrothiadiazepinoquinoline, dihydrodithiadiazepinoquinoline, tetrahydrotriazepinoquinoline, tetrahydrotetrazepinoquinoline, tetrahydrooxatriazepinoquinoline, tetrahydrothiatriazepinoquinoline, dihydrooxathiadiazepinoquinoline, dihydroimidazoquinoxaline, tetrahydropyrimidoquinoxaline, tetrahydropyrazinoquinoxaline, dihydrooxadiazinoquinoxaline, dihydrothiadiazinoquinoxaline, tetrahydrotrianinoquinoxaline, tetrahydrodiazepinoquinoxaline, tetrahydrooxadiazepinoquinoxaline, dihydrodioxadiazepinoquinoxaline, tetrahydrothiadiazepinoquinoxaline, dihydrodithiadiazepinoquinoxaline, tetrahydrotriazepinoquinoxaline, tetrahydrotetrazepinoquinoxaline, tetrahydrooxatriazepinoquinoxaline, tetrahydrothiatriazepinoquinoxaline, dihydrooxathiadiazepinoquinoxaline, dihydroimidazonaphthyridine, tetrahydropyrimidonaphthyridine, tetrahydropyrazinonaphthyridine, dihydrooxadiazinonaphthyridine, dihydrothiadiazinonaphthyridine, tetrahydrotrianinonaphthyridine, tetrahydrodiazepinonaphthyridine, tetrahydrooxadiazepinonaphthyridine, dihydrodioxadiazepinonaphthyridine, tetrahydrothiadiazepinonaphthyridine, dihydrodithiadiazepinonaphthyridine, tetrahydrotriazepinonaphthyridine, tetrahydrotetrazepinonaphthyridine, tetrahydrooxatriazepinonaphthyridine, tetrahydrothiatriazepinonaphthyridine, or dihydrooxathiadiazepinonaphthyridine.

16. The organometallic compound of claim 11, wherein R.sub.1 to R.sub.4 are each independently: hydrogen, deuterium, F, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a C.sub.1-C.sub.10 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof; a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a C.sub.1-C.sub.10 alkylphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, each unsubstituted or substituted with deuterium, F, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a C.sub.1-C.sub.10 alkylphenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), or a combination thereof; or C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), or N(Q.sub.1)(Q.sub.2), and Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 are each independently: hydrogen; deuterium; F; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; a C.sub.1-C.sub.60 alkoxy group; or a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

17. The organometallic compound of claim 11, wherein, in Formula 1, a group represented by ##STR00218## is any one selected from among Formulae CY1(1) to CY1(11), a group represented by ##STR00219## is any one selected from among Formulae CY2(1) to CY2(13), and a group represented by ##STR00220## is any one selected from among Formulae CY4(L) to CY4(29) ##STR00221## ##STR00222## ##STR00223## ##STR00224## ##STR00225## ##STR00226## ##STR00227## ##STR00228## wherein, in Formulae CY1(1) to CY1(11), CY2(1) to CY2(13), and CY4(1) to CY4(29), T.sub.21 is B(Y.sub.21), C(Y.sub.21)(Y.sub.22), N(Y.sub.21), O, S, or Si(Y.sub.21)(Y.sub.22), T.sub.22 is C(Y.sub.21), N, or Si(Y.sub.21), R.sub.11 to R.sub.17 are each as described in connection with R.sub.1 in Formula 1, R.sub.21 to R.sub.26, Y.sub.21, and Y.sub.22 are each as described in connection with R.sub.2 in Formula 1, R.sub.41 to R.sub.47 are each as described in connection with R.sub.4 in Formula 1, * indicates a binding site to M in Formula 1, * indicates a binding site to L.sub.1 in Formula 1, * indicates a binding site to L.sub.2 in Formula 1, and * indicates a binding site to L.sub.3 in Formula 1.

18. The organometallic compound of claim 11, wherein a group represented by ##STR00229## is a group represented by Formula 1A(1) or Formula 1A(2): ##STR00230## wherein, in Formulae 1A(1) and 1A(2), X.sub.3, CY.sub.31, CY.sub.32, and m are each as described in Formula 1, R.sub.31 and R.sub.32 are each as described in connection with R.sub.3 in Formula 1, a31 and a32 are each independently an integer from 1 to 20, * indicates a binding site to M in Formula 1, * indicates a binding site to L.sub.2 in Formula 1, and * indicates a binding site to L.sub.3 in Formula 1.

19. The organometallic compound of claim 11, wherein ring CY3 is a group represented by Formula 1B(1) or Formula 1B(2): ##STR00231## wherein, in Formulae 1B(1) and 1B(2), m is as described in Formula 1, X.sub.311 is C(R.sub.311) or N, X.sub.312 is C(R.sub.312) or N, X.sub.321 is C(R.sub.321) or N, X.sub.322 is C(R.sub.322) or N, X.sub.323 is C(R.sub.323) or N, and X.sub.324 is C(R.sub.324) or N, R.sub.311, R.sub.312, and R.sub.321 to R.sub.324 are each as described in connection with R.sub.3 in Formula 1, * indicates a binding site to M in Formula 1, * indicates a binding site to L.sub.2 in Formula 1, and * indicates a binding site to L.sub.3 in Formula 1.

20. The organometallic compound of claim 11, wherein the organometallic compound is a compound represented by Formula 1-1 or Formula 1-2: ##STR00232## wherein, in Formulae 1-1 and 1-2, M and m are each as described in Formula 1, L.sub.2 is *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)C(R.sub.1b)*, *C(O)*, *C(S)*, *CC*, *C[C(R.sub.1a)(R.sub.1b)]*, *Si(R.sub.1a)(R.sub.1b)*, *O*, or *S*, X.sub.12 is C(R.sub.12) or N, X.sub.13 is C(R.sub.13) or N, X.sub.14 is C(R.sub.14) or N, and X.sub.15 is C(R.sub.15) or N, X.sub.21 is C(R.sub.21) or N, X.sub.22 is C(R.sub.22) or N, and X.sub.23 is C(R.sub.23) or N, X.sub.311 is C(R.sub.311) or N, X.sub.312 is C(R.sub.312) or N, X.sub.321 is C(R.sub.321) or N, X.sub.322 is C(R.sub.322) or N, X.sub.323 is C(R.sub.323) or N, and X.sub.324 is C(R.sub.324) or N, X.sub.41 is C(R.sub.41) or N, X.sub.42 is C(R.sub.42) or N, X.sub.43 is C(R.sub.43) or N, and X.sub.44 is C(R.sub.44) or N, R.sub.11 to R.sub.15 are each as described in connection with R.sub.1 in Formula 1, R.sub.21 to R.sub.23 are each as described in connection with R.sub.2 in Formula 1, R.sub.311, R.sub.312, and R.sub.321 to R.sub.324 are each as described in connection with R.sub.3 in claim 11, R.sub.41 to R.sub.44 are each as described in connection with R.sub.4 in Formula 1, and two or more adjacent groups of R.sub.11 to R.sub.15, R.sub.21 to R.sub.23, R.sub.311, R.sub.312, R.sub.321 to R.sub.324, and R.sub.41 to R.sub.44 are optionally bonded to each other to form a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the preceding and other aspects, features, and advantages of certain embodiments of the disclosure are incorporated in and constitute a part of this specification. The drawings illustrate example embodiments and, together with the following description taken in conjunction with the accompanying drawings. In ethe drawings:

[0030] FIG. 1 is a schematic view of a structure of a light-emitting device according to one or more embodiments;

[0031] FIG. 2 is a schematic view of a structure of an electronic apparatus according to one or more embodiments;

[0032] FIG. 3 is a schematic view of a structure of an electronic apparatus according to one or more embodiments;

[0033] FIG. 4 is a block diagram of electronic equipment according to one embodiment;

[0034] FIG. 5 is a schematic diagram of electronic equipments according to one or more embodiments; and

[0035] FIGS. 6, 7, 8A, 8B, and 8C are each a diagram schematically showing a structure of electronic equipment according to one or more embodiments.

DETAILED DESCRIPTION

[0036] Reference will now be made in more detail to one or more embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout the specification, and duplicative descriptions thereof may not be provided. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, one or more embodiments are merely described in more detail, by referring to the drawings, to explain aspects of the present description.

[0037] As used herein, the term and/or includes any and all combinations of one or more of the associated listed items. Expressions such as at least one of, one of, selected from, and selected from among, when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, throughout the disclosure, the expression at least one of a, b or c indicates only a, only b, only c, both (e.g., simultaneously) a and b, both (e.g., simultaneously) a and c, both (e.g., simultaneously) b and c, all of a, b, and c, or variations thereof.

[0038] Because the disclosure may have diverse modified embodiments, the embodiments are illustrated in the drawings and are described in the detailed description. An aspect and a characteristic of the disclosure, and a method of accomplishing these will be apparent if (e.g., when) referring to one or more embodiments described with reference to the drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0039] Hereinafter, embodiments of the disclosure will be described in more detail with reference to the accompanying drawings. The same or corresponding components will be denoted by the same reference numerals, and thus redundant description thereof will not be provided.

[0040] Unless otherwise defined, all chemical names, technical and scientific terms, and terms defined in common dictionaries should be interpreted as having meanings consistent with the context of the related art, and should not be interpreted in an ideal or overly formal sense. It will be understood that although the terms first, second, and/or the like may be utilized herein to describe one or more suitable components, these components should not be limited by these terms. These terms are only utilized to distinguish one component from another. Thus, a first element could be termed a second element without departing from the teachings of the present disclosure. Similarly, a second element could be termed a first element. An expression utilized in the singular forms such as a, an, and the are intended to encompass the expression of the plural forms as well, unless it has a clearly different meaning in the context.

[0041] It will be further understood that the terms comprises, comprising, comprise, has, have, having, include, includes, and/or including, as utilized herein specify the presence of stated features or elements, but do not preclude the presence or addition of one or more other features or elements.

[0042] As used herein, the terms use, using, and used may be considered synonymous with the terms utilize, utilizing, and utilized, respectively.

[0043] The term may will be understood to refer to one or more embodiments of the present disclosure, some of which include the described element and some of which exclude that element and/or include an alternate element. Similarly, alternative language such as or refers to one or more embodiments of the present disclosure, each including a corresponding listed item.

[0044] In the following embodiments, if (e.g., when) one or more components such as layers, films, regions, plates, and/or the like are said to be connected to, or on another component, this may include not only a case in which other components are immediately on the layers, films, regions, or plates, but also a case in which other components may be placed therebetween. Sizes of elements in the drawings may be exaggerated for convenience of explanation. In other words, because sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto.

[0045] Spatially relative terms, such as beneath, below, lower, above, upper, bottom, top, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, elements described as below or beneath other elements or features would then be oriented above or over the other elements or features. Thus, the term below may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0046] In this context, consisting essentially of indicates that any additional components will not materially affect the chemical, physical, optical or electrical properties of the target portion.

[0047] Further, in this specification, the phrase on a plane, or plan view, indicates viewing a target portion from the top, and the phrase on a cross-section indicates viewing a cross-section formed by vertically cutting a target portion from the side.

Light-Emitting Device

[0048] According to an aspect of the disclosure, a light-emitting device includes: [0049] a first electrode; [0050] a second electrode opposite to (e.g., facing) the first electrode; [0051] an interlayer arranged between the first electrode and the second electrode and including an emission layer; and [0052] an organometallic compound represented by Formula 1:

##STR00004##

[0053] A more detailed description of Formula 1 is provided in the specification.

[0054] In one or more embodiments, the first electrode of the light-emitting device may be an anode, [0055] the second electrode of the light-emitting device may be a cathode, [0056] the interlayer may further include a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode, [0057] the hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and [0058] the electron transport region may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof.

[0059] In one or more embodiments, the interlayer of the light-emitting device may include the organometallic compound represented by Formula 1.

[0060] In one or more embodiments, the emission layer of the light-emitting device may include the organometallic compound represented by Formula 1.

[0061] In one or more embodiments, the emission layer of the light-emitting device may include a dopant and a host, and the organometallic compound represented by Formula 1 may be included in the dopant. For example, the organometallic compound may act as a dopant. For example, the emission layer may be to emit blue light. The blue light may have a maximum emission wavelength in a range of, for example, about 430 nm to about 480 nm.

[0062] In one or more embodiments, the electron transport region of the light-emitting device may include a hole-blocking layer, and the hole-blocking layer may include a phosphine oxide-containing compound, a silicon-containing compound, or any combination thereof. In one or more embodiments, the hole blocking layer may directly contact the emission layer.

[0063] In one or more embodiments, the light-emitting device may further include a second compound including at least one electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group, a third compound comprising a group represented by Formula 3, a fourth compound capable of emitting delayed fluorescence, or any combination thereof, [0064] wherein the organometallic compound, the second compound, the third compound, and the fourth compound in the light-emitting device may be different from each other:

##STR00005## [0065] wherein, in Formula 3, [0066] ring CY.sub.71 and ring CY.sub.72 may each independently be a electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group, [0067] X.sub.71 may be a single bond, or a linking group including O, S, N, B, C, Si, or any combination thereof, and [0068] * indicates a binding site to any atom included in a remaining portion of the third compound other than the group represented by Formula 3.

[0069] In one or more embodiments, the organometallic compound may include at least one deuterium.

[0070] In one or more embodiments, the second compound to the fourth compound may each include at least one deuterium.

[0071] In one or more embodiments, the second compound may include at least one silicon.

[0072] In one or more embodiments, the third compound may include at least one silicon.

[0073] In one or more embodiments, the light-emitting device may further include a second compound and a third compound, in addition to the organometallic compound represented by Formula 1, and at least one of the second compound and the third compound may include at least one deuterium, at least one silicon, and/or a (e.g., any suitable) combination thereof.

[0074] In one or more embodiments, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a second compound, in addition to the organometallic compound. At least one of the organometallic compound and the second compound may include at least one deuterium. For example, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a third compound, a fourth compound, or any combination thereof, in addition to the organometallic compound and the second compound.

[0075] In one or more embodiments, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a third compound, in addition to the organometallic compound. At least one of the organometallic compound and the third compound may include at least one deuterium. For example, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a second compound, a fourth compound, or any combination thereof, in addition to the organometallic compound and the third compound.

[0076] In one or more embodiments, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a fourth compound, in addition to the organometallic compound. At least one of the organometallic compound and the fourth compound may include at least one deuterium. The fourth compound may have roles in improving color purity, luminescence efficiency, and lifespan characteristics of the light-emitting device. For example, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a second compound, a third compound, or any combination thereof, in addition to the organometallic compound and the fourth compound.

[0077] In one or more embodiments, the light-emitting device (e.g., the emission layer in the light-emitting device) may further include a second compound and a third compound, in addition to the organometallic compound. The second compound and the third compound may form an exciplex. At least one of the organometallic compound, the second compound, and the third compound may include at least one deuterium.

[0078] In one or more embodiments, the emission layer in the light-emitting device may include: i) the organometallic compound; and ii) the second compound, the third compound, the fourth compound, or any combination thereof, wherein the emission layer may be to emit blue light.

[0079] In one or more embodiments, the blue light may have a maximum emission wavelength in a range of about 430 nm to about 480 nm, about 430 nm to about 475 nm, about 440 nm to about 475 nm, about 450 nm to about 475 nm, about 430 nm to about 470 nm, about 440 nm to about 470 nm, about 450 nm to about 470 nm, about 430 nm to about 465 nm, about 440 nm to about 465 nm, about 450 nm to about 465 nm, about 430 nm to about 460 nm, about 440 nm to about 460 nm, or about 450 nm to about 460 nm.

[0080] In one or more embodiments, the second compound may include a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or any combination thereof.

[0081] In one or more embodiments, the third compound may not include (e.g., may exclude) the following compounds:

##STR00006##

[0082] In one or more embodiments, the fourth compound may be a compound in which a difference between a triplet energy level (eV) and a singlet energy level (eV) is at least 0 eV but not more than 0.5 eV (or at least 0 eV but not more than 0.3 eV).

[0083] In one or more embodiments, the fourth compound may be a compound including at least one cyclic group including both (e.g., simultaneously) boron (B) and nitrogen (N) as ring-forming atoms.

[0084] In one or more embodiments, the fourth compound may be a C.sub.8-C.sub.60 polycyclic group-containing compound including two or more cyclic groups that are condensed while sharing B (e.g., a boron atom).

[0085] In one or more embodiments, the fourth compound may include a condensed ring in which at least one third ring is condensed with at least one fourth ring, [0086] wherein the third ring may be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a cyclooctene group, an adamantane group, a norbornene group, a norbornane group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, a benzene group, a pyridine group, a pyrimidine group, a pyridazine group, a pyrazine group, or a triazine group, and [0087] the fourth ring may be a 1,2-azaborinine group, a 1,3-azaborinine group, a 1,4-azaborinine group, a 1,2-dihydro-1,2-azaborinine group, a 1,4-oxaborinine group, a 1,4-thiaborinine group, or a 1,4-dihydroborinine group.

[0088] In one or more embodiments, the third compound may not include (e.g., may exclude) a compound represented by Formula 3-1 described herein.

[0089] In one or more embodiments, the second compound may include a compound represented by Formula 2:

##STR00007## [0090] wherein, in Formula 2, [0091] L.sub.51 to L.sub.53 may each independently be a single bond, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a,

[0092] b51 to b53 may each independently be an integer from 1 to 5, [0093] X.sub.54 may be N or C(R.sub.54), X.sub.55 may be N or C(R.sub.55), X.sub.56 may be N or C(R.sub.56), and at least one of X.sub.54 to X.sub.56 may be N, and [0094] R.sub.51 to R.sub.56 and R.sub.10a are each as described herein.

[0095] In one or more embodiments, the third compound may include a compound represented by Formula 3-1, a compound represented by Formula 3-2, a compound represented by Formula 3-3, a compound represented by Formula 3-4, a compound represented by Formula 3-5, or any combination thereof:

##STR00008## ##STR00009## [0096] wherein, in Formulae 3-1 to 3-5, [0097] ring CY.sub.71 to ring CY.sub.74 may each independently be a electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group, [0098] X.sub.82 may be a single bond, O, S, N-[(L.sub.82).sub.b82-R.sub.82], C(R.sub.82a)(R.sub.82b), or Si(R.sub.82a)(R.sub.82b), [0099] X.sub.83 may be a single bond, O, S, N-[(L.sub.83).sub.b83-R.sub.83], C(R.sub.83a)(R.sub.83b), or Si(R.sub.83a)(R.sub.83b), [0100] X.sub.84 may be O, S, N-[(L.sub.84).sub.b84-R.sub.84], C(R.sub.84a)(R.sub.84b), or Si(R.sub.84a)(R.sub.84b), [0101] X.sub.85 may be C or Si, [0102] L.sub.81 to L.sub.85 may each independently be a single bond, *C(Q.sub.4)(Q.sub.5)-*, *Si(Q.sub.4)(Q.sub.5)-*, a electron-rich C.sub.3-C.sub.60 cyclic group unsubstituted or substituted with at least one R.sub.10a, or a pyridine group unsubstituted or substituted with at least one R.sub.10a, wherein Q.sub.4 and Q.sub.5 are each as described in connection with Q.sub.1, [0103] b81 to b85 may each independently be an integer from 1 to 5, [0104] R.sub.71 to R.sub.74, R.sub.81 to R.sub.85, R.sub.82a, R.sub.82b, R.sub.83a, R.sub.83b, R.sub.84a, and R.sub.84b are each as described herein, [0105] a71 to a74 may each independently be an integer from 0 to 20, and [0106] R.sub.10a is as described herein.

[0107] In one or more embodiments, the fourth compound may be a compound represented by Formula 502, a compound represented by Formula 503, or any combination thereof:

##STR00010## [0108] wherein, in Formulae 502 and 503, [0109] ring A.sub.501 to ring A.sub.504 may each independently be a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, [0110] Y.sub.505 may be O, S, N(R.sub.505), B(R.sub.505), C(R.sub.505a)(R.sub.505b), or Si(R.sub.505a)(R.sub.505b), [0111] Y.sub.506 may be O, S, N(R.sub.506), B(R.sub.506), C(R.sub.506a)(R.sub.506b), or Si(R.sub.506a)(R.sub.506b), [0112] Y.sub.507 may be O, S, N(R.sub.507), B(R.sub.507), C(R.sub.507a)(R.sub.507b), or Si(R.sub.507a)(R.sub.507b), [0113] Y.sub.508 may be O, S, N(R.sub.508), B(R.sub.508), C(R.sub.508a)(R.sub.508b), or Si(R.sub.508a)(R.sub.508b), [0114] Y.sub.51 and Y.sub.52 may each independently be B, P(O), or S(O), [0115] R.sub.500a, R.sub.500b, R.sub.501 to R.sub.508, R.sub.505a, R.sub.505b, R.sub.506a, R.sub.506b, R.sub.507a, R.sub.507b, R.sub.508a, and R.sub.508b are each as described herein, and [0116] a501 to a504 may each independently be an integer from 0 to 20.

[0117] In one or more embodiments, the light-emitting device may satisfy at least one of (e.g., selected from among) Conditions 1 to 4:

Condition 1

[0118] Lowest unoccupied molecular orbital (LUMO) energy level (eV) of third compound greater than (>) LUMO energy level (eV) of organometallic compound;

Condition 2

[0119] LUMO energy level (eV) of organometallic compound greater than (>) LUMO energy level (eV) of second compound;

Condition 3

[0120] Highest occupied molecular orbital (HOMO) energy level (eV) of organometallic compound greater than (>) HOMO energy level (eV) of third compound; and

Condition 4

[0121] HOMO energy level (eV) of the third compound greater than (>) HOMO energy level (eV) of the second compound.

[0122] Each of the HOMO energy level and LUMO energy level of each of the organometallic compound, the second compound, and the third compound may be a negative value, and may be measured according to a suitable method.

[0123] In one or more embodiments, an absolute value of a difference between the LUMO energy level of the organometallic compound and the LUMO energy level of the second compound may be in a range of about 0.1 eV or more to about 1.0 eV or less, an absolute value of a difference between the LUMO energy level of the organometallic compound and the LUMO energy level of the third compound may be in a range of about 0.1 eV or more to about 1.0 eV or less, an absolute value of a difference between the HOMO energy level of the organometallic compound and the HOMO energy level of the second compound may be 1.25 eV or less (e.g., about 0.2 eV or more to about 1.25 eV or less), and an absolute value of a difference between the HOMO energy level of the organometallic compound and the HOMO energy level of the third compound may be about 1.25 eV or less (e.g., about 0.2 eV or more to about 1.25 eV or less).

[0124] When the relationships between the LUMO energy level and HOMO energy level satisfy the aforementioned conditions, a balance between holes and electrons injected into the emission layer may be achieved.

[0125] The light-emitting device may have a structure of a first embodiment or a second embodiment.

First Embodiment

[0126] According to the first embodiment, the emission layer of the interlayer in the light-emitting device may include the organometallic compound, and may further include a host, wherein the organometallic compound and the host may be different from each other, and the emission layer may be to emit phosphorescence or fluorescence emitted from the organometallic compound. For example, according to the first embodiment, the organometallic compound may be a dopant or an emitter. For example, the organometallic compound may be a phosphorescent dopant or a phosphorescent emitter.

[0127] Phosphorescence or fluorescence emitted from the organometallic compound may be blue light.

[0128] The emission layer may further include an auxiliary dopant. The auxiliary dopant may effectively transfer energy to the organometallic compound which serves as a dopant or an emitter, and in this regard, the auxiliary dopant may serve to improve luminescence efficiency of the organometallic compound.

[0129] The auxiliary dopant may be different from each of the organometallic compound and the host.

[0130] In one or more embodiments, the auxiliary dopant may be a compound emitting delayed fluorescence.

[0131] In one or more embodiments, the auxiliary dopant may be a compound including at least one cyclic group including both (e.g., simultaneously) B and N as ring-forming atoms.

Second Embodiment

[0132] According to the second embodiment, the emission layer of the interlayer in the light-emitting device may include the organometallic compound, and may further include a host and a dopant, wherein the organometallic compound, the host, and the dopant may be different from each other, and the emission layer may be to emit phosphorescence or fluorescence (e.g., delayed fluorescence) emitted from the dopant.

[0133] In one or more embodiments, the organometallic compound in the second embodiment is not a dopant, and may rather serve as an auxiliary dopant that transfers energy to a dopant (or an emitter).

[0134] In one or more embodiments, the organometallic compound in the second embodiment may serve as an emitter, and may also serve as an auxiliary dopant that transfers energy to a dopant (or an emitter).

[0135] For example, phosphorescence or fluorescence emitted from the dopant (or the emitter) in the second embodiment may be blue phosphorescence or blue fluorescence (e.g., blue delayed fluorescence).

[0136] The dopant (or the emitter) in the second embodiment may be a phosphorescent dopant material (e.g., the organometallic compound represented by Formula 1, an organometallic compound represented by Formula 401, or any combination thereof) or any fluorescent dopant material (e.g., a compound represented by Formula 501, the compound represented by Formula 502, the compound represented by Formula 503, or any combination thereof).

[0137] In the first embodiment and the second embodiment, the blue light may be blue light having a maximum emission wavelength in a range of about 390 nm to about 500 nm, about 410 nm to about 490 nm, about 430 nm to about 480 nm, about 440 nm to about 475 nm, or about 455 nm to about 470 nm.

[0138] The auxiliary dopant in the first embodiment may include, for example, the compound represented by Formula 502 or Formula 503 as the fourth compound.

[0139] In one or more embodiments, the host in the first embodiment and the second embodiment may be any (e.g., any suitable) host material (e.g., a compound represented by Formula 301, a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof).

[0140] In one or more embodiments, the host in the first embodiment and the second embodiment may be the second compound, the third compound, or any combination thereof.

[0141] In one or more embodiments, the light-emitting device may further include a capping layer arranged outside the first electrode and/or outside the second electrode.

[0142] In one or more embodiments, the light-emitting device may further include at least one of a first capping layer arranged outside the first electrode and a second capping layer arranged outside the second electrode, wherein at least one of the first capping layer and/or the second capping layer may include the organometallic compound represented by Formula 1. More details on the first capping layer and/or the second capping layer may be referred to the descriptions provided herein.

[0143] In one or more embodiments, the light-emitting device may include:

[0144] a first capping layer arranged outside (e.g., and on) the first electrode and including the organometallic compound represented by Formula 1;

[0145] a second capping layer arranged outside (e.g., and on) the second electrode and including the organometallic compound represented by Formula 1; or

[0146] the first capping layer and the second capping layer.

[0147] The wording (interlayer and/or capping layer) includes an organometallic compound represented by Formula 1 as used herein may be understood as (interlayer and/or capping layer) may include one kind of organometallic compound represented by Formula 1 or two or more different kinds of organometallic compounds, each represented by Formula 1.

[0148] In one or more embodiments, the interlayer and/or the capping layer may include Compound 1 only as the organometallic compound. In this regard, Compound 1 may be present in the emission layer of the light-emitting device. In one or more embodiments, the interlayer may include, as the organometallic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may be present in substantially the same layer (e.g., both (e.g., simultaneously) Compound 1 and Compound 2 may be present in the emission layer), or may be present in different layers (e.g., Compound 1 may be present in the emission layer, and Compound 2 may be present in the electron transport region).

[0149] The term interlayer as used herein refers to a single layer and/or each (e.g., any or all) of multiple layers arranged between the first electrode and the second electrode of the light-emitting device.

[0150] According to another aspect of the disclosure, an electronic apparatus includes the light-emitting device. The electronic apparatus may further include a thin-film transistor. For example, the electronic apparatus may further include a thin-film transistor including a source electrode and a drain electrode, wherein the first electrode of the light-emitting device may be electrically connected to the source electrode or the drain electrode. In one or more embodiments, the electronic apparatus may further include a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof. More details on the electronic apparatus may be referred to the descriptions provided herein.

[0151] According to another aspect of the disclosure, electronic equipment includes the light-emitting device.

[0152] For example, the electronic equipment may be at least one of (e.g., any one selected from among) a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, an indoor or outdoor light and/or light for signal, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a portable phone, a tablet personal computer, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro display, a three-dimensional (3D) display, a virtual reality or augmented reality display, a vehicle, a video wall with multiple displays tiled together, a theater or stadium screen, a phototherapy device, a signboard, and/or combination(s) thereof.

[0153] According to another aspect of the disclosure, provided is the organometallic compound represented by Formula 1. For a description of Formula 1, reference may be made to the specification.

[0154] Synthesis methods of the organometallic compound may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples and/or Examples provided.

Descriptions of Formulae 1 and 1A

##STR00011##

[0155] In Formula 1, M may be platinum (Pt), palladium (Pd), copper (Cu), silver (Ag), gold (Au), rhodium (Rh), ruthenium (Ru), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm).

[0156] In one or more embodiments, M may be Pt, Pd, or Au.

[0157] In one or more embodiments, M may be Pt.

[0158] X.sub.1 to X.sub.4 in Formula 1 may each independently be C or N.

[0159] In one or more embodiments, X.sub.1 may be C.

[0160] In one or more embodiments, X.sub.1 may be C, and [0161] a bond between X.sub.1 and M may be a coordinate bond.

[0162] In one or more embodiments, X.sub.1 may be C of a carbene moiety.

[0163] In one or more embodiments, X.sub.2 and X.sub.3 may each be C, and [0164] X.sub.4 may be N.

[0165] In one or more embodiments, i) a bond between X.sub.1 and M may be a coordinate bond, and [0166] ii) one of a bond between X.sub.2 and M, a bond between X.sub.3 and M, and a bond between X.sub.4 and M may be a coordinate bond, and the other two bonds may each be a covalent bond.

[0167] In one or more embodiments, a bond between X.sub.1 and M and a bond between X.sub.4 and M may each be a coordinate bond, and [0168] a bond between X.sub.2 and M and a bond between X.sub.3 and M may each be a covalent bond.

[0169] In one or more embodiments, X.sub.1, X.sub.2, and X.sub.3 may each be C, and X.sub.4 may be N, [0170] a bond between X.sub.1 and M and a bond between X.sub.4 and M may each be a coordinate bond, and [0171] a bond between X.sub.2 and M and a bond between X.sub.3 and M may each be a covalent bond.

[0172] In Formula 1, ring CY.sub.1 to ring CY.sub.4 may each independently be a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group.

[0173] In one or more embodiments, ring CY.sub.1, ring CY.sub.2, and ring CY.sub.4 may each independently be [0174] a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silol group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilol group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilol group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a dibenzoxacillin group, a dibenzothiacillin group, a dibenzodihydroazacillin group, a dibenzodihydrodicillin group, a dibenzodihydrocillin group, a dibenzodioxin group, a dibenzoxathiin group, a dibenzoxazine group, a dibenzopyran group, a dibenzodithiin group, a dibenzothiazine group, a dibenzothiopyran group, a dibenzocyclohexadiene group, a dibenzodihydropyridine group, or a dibenzodihydropyrazine group.

[0175] In one or more embodiments, ring CY.sub.1 may be an imidazole group, a triazole group, a benzimidazole group, a naphthoimidazol group, or an imidazopyridine group.

[0176] In one or more embodiments, ring CY.sub.2 may be a benzene group, a pyridine group, a pyrimidine group, a naphthalene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, a naphthobenzofuran group, a naphthobenzothiophene group, a benzocarbazole group, a benzofluorene group, a naphthobenzosilole group, a dinaphthofuran group, a dinaphthothiophene group, a dibenzocarbazole group, a dibenzofluorene group, a dinaphthosilole group, an azadibenzofuran group, an azadibenzothiophene group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azanaphthobenzofuran group, an azanaphthobenzothiophene group, an azabenzocarbazole group, an azabenzofluorene group, an azanaphthobenzosilole group, an azadinaphthofuran group, an azadinaphthothiophene group, an azadibenzocarbazole group, an azadibenzofluorene group, or an azadinaphthosilole group.

[0177] In one or more embodiments, ring CY.sub.2 may be a benzene group, a pyridine group, a pyrimidine group, a naphthalene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, a fluorene group, or a dibenzosilole group.

[0178] In one or more embodiments, ring CY.sub.4 may be a nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

[0179] In one or more embodiments, ring CY.sub.4 may be a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, a benzopyrazole group, a benzimidazole group, or a benzothiazole group.

[0180] In one or more embodiments, ring CYs may be a nitrogen-containing bridged C.sub.1-C.sub.60 heteropolycyclic group.

[0181] In one or more embodiments, ring CYs may be a nitrogen-containing bridged C.sub.1-C.sub.60 heteropolycyclic group in which two or more C.sub.1-C.sub.30 heterocyclic groups are condensed with each other.

[0182] In one or more embodiments, ring CYs may be a nitrogen-containing bridged C.sub.1-C.sub.60 heteropolycyclic group in which two or more C.sub.1-C.sub.30 heterocyclic groups are condensed with each other, and

[0183] the C.sub.1-C.sub.30 heterocyclic group may be dihydrobenzimidazole, tetrahydroquinazoline, tetrahydroquinoxaline, dihydrobenzooxadiazine, dihydrobenzothiadiazine, tetrahydrobenzotriazine, tetrahydrobenzodiazepine, tetrahydrobenzooxadiazepine, dihydrobenzodioxadiazepine, tetrahydrobenzothiadiazepine, dihydrobenzodithiadiazepine, tetrahydrobenzotriazepine, tetrahydrobenzotetrazepine, tetrahydrobenzooxatriazepine, tetrahydrobenzothiatriazepine, dihydrobenzooxathiadiazepine, dihydronaphthoimidazole, tetrahydrobenzoquinazoline, tetrahydrobenzoquinoxaline, dihydronaphthooxadiazine, dihydronaphthothiadiazine, tetrahydronaphthotriazine, tetrahydronaphthodiazepine, tetrahydronaphthooxadiazepine, dihydronaphthodioxadiazepine, tetrahydronaphthothiadiazepine, dihydronaphthodithiadiazepine, tetrahydronaphthotriazepine, tetrahydronaphthotetrazepine, tetrahydronaphthooxatriazepine, tetrahydronaphthothiatriazepine, dihydronaphthooxathiadiazepine, dihydroimidazopyridine, tetrahydropyridopyrimidine, tetrahydropyridopyrazine, dihydropyridooxadiazine, dihydropyridothiadiazine, tetrahydropyridotriazine, tetrahydropyridodiazepine, tetrahydropyridooxadiazepine, dihydropyridodioxadiazepine, tetrahydropyridothiadiazepine, dihydropyridodithiadiazepine, tetrahydropyridotriazepine, tetrahydropyridotetrazepine, tetrahydropyridooxatriazepine, tetrahydropyridothiatriazepine, dihydropyridooxathiadiazepine, dihydropurine, tetrahydropyridopyrimidine, tetrahydropteridine, dihydropyrimidooxadiazine, dihydropyrimidothiadiazine, tetrahydropyrimidotriazine, tetrahydropyrimidodiazepine, tetrahydropyrimidooxadiazepine, dihydropyrimidodioxadiazepine, tetrahydropyrimidothiadiazepine, dihydropyrimidodithiadiazepine, tetrahydropyrimidotriazepine, tetrahydropyrimidotetrazepine, tetrahydropyrimidooxatriazepine, tetrahydropyrimidothiatriazepine, dihydropyrimidooxathiadiazepine, dihydroimidazopyridazine, tetrahydropyrimidopyridazine, tetrahydropyridazinopyrazine, dihydropyridazinooxadiazine, dihydropyridazinothiadiazine, tetrahydropyridazinotriazine, tetrahydropyridazinodiazepine, tetrahydropyridazinooxadiazepine, dihydropyridazinodioxadiazepine, tetrahydropyridazinothiadiazepine, dihydropyridazinodithiadiazepine, tetrahydropyridazinotriazepine, tetrahydropyridazinotetrazepine, tetrahydropyridazinooxatriazepine, tetrahydropyridazinothiatriazepine, dihydropyridazinooxathiadiazepine, dihydroimidazopyrazine, tetrahydropyrazinopyrazine, dihydropyrazinooxadiazine, dihydropyrazinothiadiazine, tetrahydropyrazinotriazine, tetrahydropyrazinodiazepine, tetrahydropyrazinooxadiazepine, dihydropyrazinodioxadiazepine, tetrahydropyrazinothiadiazepine, dihydropyrazinodithiadiazepine, tetrahydropyrazinotriazepine, tetrahydropyrazinotetrazepine, tetrahydropyrazinooxatriazepine, tetrahydropyrazinothiatriazepine, dihydropyrazinooxathiadiazepine, dihydroimidazoquinoline, tetrahydropyrimidoquinoline, tetrahydropyrazinoquinoline, dihydrooxadiazinoquinoline, dihydrothiadiazinoquinoline, tetrahydrotrianinoquinoline, tetrahydrodiazepinoquinoline, tetrahydrooxadiazepinoquinoline, dihydrodioxadiazepinoquinoline, tetrahydrothiadiazepinoquinoline, dihydrodithiadiazepinoquinoline, tetrahydrotriazepinoquinoline, tetrahydrotetrazepinoquinoline, tetrahydrooxatriazepinoquinoline, tetrahydrothiatriazepinoquinoline, dihydrooxathiadiazepinoquinoline, dihydroimidazoquinoxaline, tetrahydropyrimidoquinoxaline, tetrahydropyrazinoquinoxaline, dihydrooxadiazinoquinoxaline, dihydrothiadiazinoquinoxaline, tetrahydrotrianinoquinoxaline, tetrahydrodiazepinoquinoxaline, tetrahydrooxadiazepinoquinoxaline, dihydrodioxadiazepinoquinoxaline, tetrahydrothiadiazepinoquinoxaline, dihydrodithiadiazepinoquinoxaline, tetrahydrotriazepinoquinoxaline, tetrahydrotetrazepinoquinoxaline, tetrahydrooxatriazepinoquinoxaline, tetrahydrothiatriazepinoquinoxaline, dihydrooxathiadiazepinoquinoxaline, dihydroimidazonaphthyridine, tetrahydropyrimidonaphthyridine, tetrahydropyrazinonaphthyridine, dihydrooxadiazinonaphthyridine, dihydrothiadiazinonaphthyridine, tetrahydrotrianinonaphthyridine, tetrahydrodiazepinonaphthyridine, tetrahydrooxadiazepinonaphthyridine, dihydrodioxadiazepinonaphthyridine, tetrahydrothiadiazepinonaphthyridine, dihydrodithiadiazepinonaphthyridine, tetrahydrotriazepinonaphthyridine, tetrahydrotetrazepinonaphthyridine, tetrahydrooxatriazepinonaphthyridine, tetrahydrothiatriazepinonaphthyridine, or dihydrooxathiadiazepinonaphthyridine.

[0184] In one or more embodiments, ring CY.sub.3 may be a nitrogen-containing bridged C.sub.1-C.sub.60 heteropolycyclic group in which two or more C.sub.1-C.sub.30 heterocyclic groups are condensed with each other, and

[0185] the C.sub.1-C.sub.30 heterocyclic group may be dihydrobenzimidazole, tetrahydroquinazoline, tetrahydroquinoxaline, dihydronaphthoimidazole, tetrahydrobenzoquinazoline, tetrahydrobenzoquinoxaline, dihydroimidazopyridine, tetrahydropyridopyrimidine, tetrahydropyridopyrazine, dihydropurine, tetrahydropyrimidopyrimidine, tetrahydropteridine, dihydroimidazopyridazine, tetrahydropyrimidopyridazine, tetrahydropyridazinopyrazine, dihydroimidazopyrazine, tetrahydropyrazinopyrazine, dihydroimidazoquinoline, tetrahydropyrimidoquinoline, tetrahydropyrazinoquinoline, dihydroimidazoquinoxaline, tetrahydropyrimidoquinoxaline, tetrahydropyrazinoquinoxaline, dihydroimidazonaphthyridine, tetrahydropyrimidonaphthyridine, or tetrahydropyrazinonaphthyridine.

[0186] In Formula 1, L.sub.1 to L.sub.3 may each independently be a single bond, *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)*, *C(R.sub.1a)*, *C(R.sub.1a)C(R.sub.1b)*, *C[C(R.sub.1a)(R.sub.1b)]*, *C(O)*, *C(S)*, *CC*, *B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(R.sub.1a)*, *Al(R.sub.1a)*, *Si(R.sub.1a)(R.sub.1b)*, *P(O)(R.sub.1a)*, *S*, *S(O)*, *S(O).sub.2*, or *Ge(R.sub.1a)(R.sub.1b)*, and * and * each indicate a binding site to a neighboring atom.

[0187] Ria and Rib may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2).

[0188] R.sub.10a and Q.sub.1 to Q.sub.3 are each as described herein.

[0189] In Formula 1, n1 to n3 indicate the number of L.sub.1 to the number of L.sub.3, respectively, and may each independently be an integer from 1 to 10. When n1 is 2 or more, two or more of L.sub.1 may be substantially identical to or different from each other, if (e.g., when) n2 is 2 or more, two or more of L.sub.2 may be substantially identical to or different from each other, and if (e.g., when) n3 is 2 or more, two or more of L.sub.3 may be substantially identical to or different from each other.

[0190] In one or more embodiments, L.sub.1 and L.sub.3 may each be a single bond.

[0191] In one or more embodiments, L.sub.2 may be *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)C(R.sub.1b)*, *C(O)*, *C(S)*, *CC*, *C[C(R.sub.1a)(R.sub.1b)]*, *Si(R.sub.1a)(R.sub.1b)*, *O*, or *S*, and n2 may be 1.

[0192] In one or more embodiments, R.sub.1a and R.sub.1b may each independently be: [0193] hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; [0194] a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, Cl, Br, I, CDs, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.1 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof;

[0195] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, or an azadibenzosilolyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoisoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof; or [0196] C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), and [0197] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: hydrogen; deuterium; F; CI; Br; I; a hydroxyl group; a cyano group; a nitro group; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; a C.sub.1-C.sub.60 alkoxy group; or a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

[0198] In Formula 1, R.sub.1 to R.sub.4 may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2).

[0199] R.sub.10a and Q.sub.1 to Q.sub.3 are each as described herein.

[0200] In Formula 1, a1 to a4 indicate the number of R.sub.1 to the number of R.sub.4, respectively, and may each independently be an integer from 1 to 20. When a1 is 2 or more, two or more of R.sub.1 may be substantially identical to or different from each other, if (e.g., when) a2 is 2 or more, two or more of R.sub.2 may be substantially identical to or different from each other, if (e.g., when) a3 is 2 or more, two or more of R.sub.3 may be substantially identical to or different from each other, and if (e.g., when) a4 is 2 or more, two or more of R.sub.4 may be substantially identical to or different from each other.

[0201] In one or more embodiments, R.sub.1 to R.sub.4 may each independently be: [0202] hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; [0203] a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, Cl, Br, I, CDs, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.1 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof; [0204] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzothiazolyl group, a benzoisoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, or an azadibenzosilolyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoisoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof; or [0205] C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), and [0206] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: hydrogen; deuterium; F; CI; Br; I; a hydroxyl group; a cyano group; a nitro group; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; a C.sub.1-C.sub.60 alkoxy group; or a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

[0207] In one or more embodiments, R.sub.1 to R.sub.4 may each independently be: [0208] hydrogen, deuterium, F, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; [0209] a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a C.sub.1-C.sub.1 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof; [0210] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.1 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, each unsubstituted or substituted with deuterium, F, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), and/or a (e.g., any suitable) combination thereof; or [0211] C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), or N(Q.sub.1)(Q.sub.2), and [0212] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: hydrogen; deuterium; F; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; a C.sub.1-C.sub.60 alkoxy group; or a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

[0213] In one or more embodiments, R.sub.1 to R.sub.4 may each independently be: [0214] hydrogen, deuterium, or a C.sub.1-C.sub.20 alkyl group; [0215] a C.sub.1-C.sub.20 alkyl group substituted with deuterium, CD.sub.3, CD.sub.2H, CDH.sub.2, a C.sub.1-C.sub.1 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, or any combination thereof; [0216] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.1 alkyl)phenyl group, or a naphthyl group, each unsubstituted or substituted with deuterium, CD.sub.3, CD.sub.2H, CDH.sub.2, a C.sub.1-C.sub.20 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.1 alkyl)phenyl group, a naphthyl group, Si(Q.sub.31)(Q.sub.32)(Q.sub.33), or any combination thereof; or [0217] C(Q.sub.1)(Q.sub.2)(Q.sub.3) or Si(Q.sub.1)(Q.sub.2)(Q.sub.3), and [0218] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: hydrogen; deuterium; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; or a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with deuterium, a C.sub.1-C.sub.60 alkyl group, a phenyl group, a biphenyl group, or any combination thereof.

[0219] In one or more embodiments, two or more neighboring groups of R.sub.1 in the number of a1, R.sub.11, R.sub.2 in the number of a2, R.sub.3 in the number of a3, R.sub.4 in the number of a4, R.sub.1a, and R.sub.1b may optionally be bonded to each other to form a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a.

[0220] In Formula 1, ring CY.sub.3 may include a moiety represented by Formula 1A.

[0221] In Formula 1A, ring CY.sub.31 and ring CY.sub.32 may each independently be a C.sub.1-C.sub.30 heterocyclic group.

[0222] In one or more embodiments, ring CY.sub.31 and ring CY.sub.32 may each independently be dihydrobenzimidazole, tetrahydroquinazoline, tetrahydroquinoxaline, dihydrobenzooxadiazine, dihydrobenzothiadiazine, tetrahydrobenzotriazine, tetrahydrobenzodiazepine, tetrahydrobenzooxadiazepine, dihydrobenzodioxadiazepine, tetrahydrobenzothiadiazepine, dihydrobenzodithiadiazepine, tetrahydrobenzotriazepine, tetrahydrobenzotetrazepine, tetrahydrobenzooxatriazepine, tetrahydrobenzothiatriazepine, dihydrobenzooxathiadiazepine, dihydronaphthoimidazole, tetrahydrobenzoquinazoline, tetrahydrobenzoquinoxaline, dihydronaphthooxadiazine, dihydronaphthothiadiazine, tetrahydronaphthotriazine, tetrahydronaphthodiazepine, tetrahydronaphthooxadiazepine, dihydronaphthodioxadiazepine, tetrahydronaphthothiadiazepine, dihydronaphthodithiadiazepine, tetrahydronaphthotriazepine, tetrahydronaphthotetrazepine, tetrahydronaphthooxatriazepine, tetrahydronaphthothiatriazepine, dihydronaphthooxayhiadiazepine, dihydroimidazopyridine, tetrahydropyridopyrimidine, tetrahydropyridopyrazine, dihydropyridooxadiazine, dihydropyridothiadiazine, tetrahydropyridotriazine, tetrahydropyridodiazepine, tetrahydropyridooxadiazepine, dihydropyridodioxadiazepine, tetrahydropyridothiadiazepine, dihydropyridodithiadiazepine, tetrahydropyridotriazepine, tetrahydropyridotetrazepine, tetrahydropyridooxatriazepine, tetrahydropyridothiatriazepine, dihydropyridooxathiadiazepine, dihydropurine, tetrahydropyrimidopyrimidine, tetrahydropteridine, dihydropyrimidooxadiazine, dihydropyrimidothiadiazine, tetrahydropyrimidoa triazine, tetrahydropyrimidodiazepine, tetrahydrpyrimidooxadiazepine, dihydropyrimidodioxadiazepine, tetrahydropyrimidothiadiazepine, dihydropyrimidodithiadiazepine, tetrahydropyrimidotriazepine, tetrahydropyrimidotetrazepine, tetrahydropyrimidooxatriazepine, tetrahydropyrimidothiatriazepine, dihydropyrimidooxathiadiazepine, dihydroan imidazopyridazine, tetrahydropyrimidopyridazine, tetrahydropyridazinopyrazine, dihydropyridazinooxadiazine, dihydropyridazinothiadiazine, tetrahydropyridazinotriazine, tetrahydropyridazinodiazepine, tetrahydropyridazinooxadiazepine, dihydropyridazinodioxadiazepine, tetrahydropyridazinothiadiazepine, dihydropyridazinodithiadiazepine, tetrahydropyridazinotriazepine, tetrahydropyridazinotetrazepine, tetrahydropyridazinooxatriazepine, tetrahydropyridazinothiatriazepine, dihydropyridazinooxathiadiazepine, dihydroimidazopyrazine, tetrahydropyrazinopyrazine, dihydropyrazinooxadiazine, dihydropyrazinothiadiazine, tetrahydropyrazinotriazine, tetrahydropyrazinodiazepine, tetrahydropyrazinooxadiazepine, dihydropyrazinodioxadiazepine, tetrahydropyrazinothiadiazepine, dihydropyrazinodithiadiazepine, tetrahydropyrazinotriazepine, tetrahydropyrazinotetrazepine, tetrahydropyrazinooxatriazepine, tetrahydropyrazinothiatriazepine, dihydropyrazinooxathiadiazepine, dihydroimidazoquinoline, tetrahydropyrimidoquinoline, tetrahydropyrazinoquinoline, dihydrooxadiazinoquinoline, dihydrothiadiazinoquinoline, tetrahydrotrianinoquinoline, tetrahydrodiazepinoquinoline, tetrahydrooxadiazepinoquinoline, dihydrodioxadiazepinoquinoline, tetrahydrothiadiazepinoquinoline, dihydrodithiadiazepinoquinoline, tetrahydrotriazepinoquinoline, tetrahydrotetrazepinoquinoline, tetrahydrooxatriazepinoquinoline, tetrahydrothiatriazepinoquinoline, dihydrooxathiadiazepinoquinoline, dihydroimidazoquinoxaline, tetrahydropyrimidoquinoxaline, tetrahydropyrazinoquinoxaline, dihydrooxadiazinoquinoxaline, dihydrothiadiazinoquinoxaline, tetrahydrotrianinoquinoxaline, tetrahydrodiazepinoquinoxaline, tetrahydrooxadiazepinoquinoxaline, dihydrodioxadiazepinoquinoxaline, tetrahydrothiadiazepinoquinoxaline, dihydrodithiadiazepinoquinoxaline, tetrahydrotriazepinoquinoxaline, tetrahydrotetrazepinoquinoxaline, tetrahydrooxatriazepinoquinoxaline, tetrahydrothiatriazepinoquinoxaline, dihydrooxathiadiazepinoquinoxaline, dihydroimidazonaphthyridine, tetrahydropyrimidonaphthyridine, tetrahydropyrazinonaphthyridine, dihydrooxadiazinonaphthyridine, dihydrothiadiazinonaphthyridine, tetrahydrotrianinonaphthyridine, tetrahydrodiazepinonaphthyridine, tetrahydrooxadiazepinonaphthyridine, dihydrodioxadiazepinonaphthyridine, tetrahydrothiadiazepinonaphthyridine, dihydrodithiadiazepinonaphthyridine, tetrahydrotriazepinonaphthyridine, tetrahydrotetrazepinonaphthyridine, tetrahydrooxatriazepinonaphthyridine, tetrahydrothiatriazepinonaphthyridine, or dihydrooxathiadiazepinonaphthyridine.

[0223] In one or more embodiments, ring CY.sub.31 and ring CY.sub.32 may each independently be dihydrobenzimidazole, tetrahydroquinazoline, tetrahydroquinoxaline, dihydronaphthoimidazole, tetrahydrobenzoquinazoline, tetrahydrobenzoquinoxaline, dihydroimidazopyridine, tetrahydropyridopyrimidine, tetrahydropyridopyrazine, dihydropurine, tetrahydropyridimopyrimidine, tetrahydropteridine, dihydroimidazopyridazine, tetrahydropyrimidopyridazine, tetrahydropyridazinopyrazine, dihydroimidazopyrazine, tetrahydropyrazinopyrazine, dihydroimidazoquinoline, tetrahydropyrimidoquinoline, tetrahydropyrazinoquinoline, dihydroimidazoquinoxaline, tetrahydropyrimidoquinoxaline, tetrahydropyrazinoquinoxaline, dihydroimidazonaphthyridine, tetrahydropyrimidonaphthyridine, or tetrahydropyrazinonaphthyridine.

[0224] In Formula 1A, m indicates the number of *(CH.sub.2)* included in a bridge shared by ring CY.sub.31 and ring CY.sub.32 which are condensed with each other, and may be an integer from 1 to 5.

[0225] In one or more embodiments, in Formula 1, a group represented by

##STR00012##

may be a group represented by one of (e.g., any one selected from among) Formulae CY1(1) to CY1(11):

##STR00013## ##STR00014## [0226] wherein, in Formulae CY1(1) to CY1(11), [0227] R.sub.11 to R.sub.17 are each as described in connection with R.sub.1, [0228] * indicates a binding site to M in Formula 1, and [0229] * indicates a binding site to L.sub.1 in Formula 1.

[0230] In one or more embodiments, R.sub.11 in Formulae CY1(1) to CY1(11) may be: [0231] CH.sub.3, CD.sub.3, CD.sub.2H, CDH.sub.2, CH.sub.2CH.sub.3, CH.sub.2CD.sub.3, CH.sub.2CD.sub.2H, CH.sub.2CDH.sub.2, CHDCH.sub.3, CHDCD.sub.2H, CHDCDH.sub.2, CHDCD.sub.3, CD.sub.2CD.sub.3, CD.sub.2CD.sub.2H, or CD.sub.2CDH.sub.2; [0232] an n-propyl group, an iso-propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, or a tert-pentyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.10 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof; or [0233] a group represented by one of Formulae R-1 to R-3:

##STR00015## [0234] wherein, in Formulae R-1 to R-3, [0235] X.sub.111 may be C(R.sub.111) or N, X.sub.112 may be C(R.sub.112) or N, X.sub.113 may be C(R.sub.113) or N, X.sub.114 may be C(R.sub.114) or N, and X.sub.115 may be C(R.sub.115) or N, [0236] X.sub.116 may be C(R.sub.116), N, O, or S, X.sub.117 may be C(R.sub.117), N, O, or S, X.sub.118 may be C(R.sub.118), N, O, or S, and X.sub.119 may be C(R.sub.119), N, O, or S, [0237] R.sub.111 to R.sub.119 may each independently be: [0238] hydrogen, deuterium, CH.sub.3, CD.sub.3, CD.sub.2H, CDH.sub.2, CH.sub.2CH.sub.3, CH.sub.2CD.sub.3, CH.sub.2CD.sub.2H, CH.sub.2CDH.sub.2, CHDCH.sub.3, CHDCD.sub.2H, CHDCDH.sub.2, CHDCD.sub.3, CD.sub.2CD.sub.3, CD.sub.2CD.sub.2H, or CD.sub.2CDH.sub.2; or [0239] an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.10 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof, and [0240] * indicates a binding site to a neighboring atom.

[0241] In one or more embodiments, R.sub.11 in Formulae CY1(1) to CY1(11) may be a group represented by Formula R-1, and

[0242] X.sub.111 may be C(R.sub.111).

[0243] In one or more embodiments, R.sub.11 in Formulae CY1(1) to CY1(11) may be a group represented by Formula R-1, and

[0244] X.sub.112 may be C(R.sub.112), and X.sub.114 may be C(R.sub.114).

[0245] In one or more embodiments, R.sub.11 in Formulae CY1(1) to CY1(11) may be a group represented by Formula R-1, and

[0246] X.sub.112 may be C(R.sub.112), X.sub.113 may be N, and X.sub.114 may be C(R.sub.114).

[0247] In one or more embodiments, R.sub.11 in Formulae CY1(1) to CY1(11) may be a group represented by Formula R-1, and

[0248] X.sub.111 may be C(R.sub.111), and X.sub.115 may be C(R.sub.115).

[0249] In one or more embodiments, a group represented by

##STR00016##

in Formula 1 may be a group represented by one of (e.g., any one selected from among) Formulae CY2(1) to CY2(13):

##STR00017## ##STR00018## ##STR00019## [0250] wherein, in Formulae CY2(1) to CY2(13), [0251] T.sub.21 may be B(Y.sub.21), C(Y.sub.21)(Y.sub.22), N(Y.sub.21), O, S, or Si(Y.sub.21)(Y.sub.22), [0252] T.sub.22 may be C(Y.sub.21), N, or Si(Y.sub.21), [0253] R.sub.21 to R.sub.26, Y.sub.21, and Y.sub.22 are each as described in connection with R.sub.2, [0254] * indicates a binding site to M in Formula 1, [0255] * indicates a binding site to L.sub.1 in Formula 1, and [0256] * Y indicates a binding site to L.sub.2 in Formula 1.

[0257] In one or more embodiments, in Formula 1, a group represented by

##STR00020##

may be a group represented by one of (e.g., any one selected from among) Formulae CY4(1) to CY4(29):

##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025## [0258] wherein, in Formulae CY4(1) to CY4(29), [0259] R.sub.41 to R.sub.47 are each as described in connection with R.sub.4, [0260] * indicates a binding site to M in Formula 1, and [0261] * indicates a binding site to L.sub.3 in Formula 1.

[0262] In one or more embodiments, a group represented by

##STR00026##

may be a group represented by Formula 1A(1) or Formula 1A(2):

##STR00027## [0263] wherein, in Formulae 1A(1) and 1A(2), [0264] X.sub.3, CY.sub.31, CY.sub.32, and m may each independently be as described herein, [0265] R.sub.31 and R.sub.32 are each as described in connection with R.sub.3, [0266] a31 and a32 may each independently be an integer from 1 to 20, [0267] * indicates a binding site to M in Formula 1, [0268] * indicates a binding site to L.sub.2 in Formula 1, and [0269] * indicates a binding site to L.sub.3 in Formula 1.

[0270] In one or more embodiments, ring CY.sub.3 may be a group represented by Formula 1B(1) or Formula 1B(2):

##STR00028## [0271] wherein, in Formulae 1B(1) and 1B(2), [0272] m is as described herein, [0273] X.sub.311 may be C(R.sub.311) or N, X.sub.312 may be C(R.sub.312) or N, X.sub.321 may be C(R.sub.321) or N, X.sub.322 may be C(R.sub.322) or N, X.sub.323 may be C(R.sub.323) or N, and X.sub.324 may be C(R.sub.324) or N, [0274] R.sub.311, R.sub.312, and R.sub.321 to R.sub.324 are each as described in connection with R.sub.3, [0275] * indicates a binding site to M in Formula 1, [0276] * indicates a binding site to L.sub.2 in Formula 1, and [0277] * indicates a binding site to L.sub.3 in Formula 1.

[0278] In one or more embodiments, the organometallic compound represented by Formula 1 may be a compound represented by Formula 1-1 or Formula 1-2:

##STR00029## [0279] wherein, in Formulae 1-1 and 1-2, [0280] M and m are each as described herein, [0281] L.sub.2 may be *C(R.sub.1a)(R.sub.1b)*, *C(R.sub.1a)C(R.sub.1b)*, *C(O)*, *C(S)*, *CC* *C[C(R.sub.1a)(R.sub.1b)]*, *Si(R.sub.1a)(R.sub.1b)*, *O*, or *S*, [0282] X.sub.12 may be C(R.sub.12) or N, X.sub.13 may be C(R.sub.13) or N, X.sub.14 may be C(R.sub.14) or N, and X.sub.15 may be C(R.sub.15) or N, [0283] X.sub.21 may be C(R.sub.21) or N, X.sub.22 may be C(R.sub.22) or N, and X.sub.23 may be C(R.sub.23) or N, [0284] X.sub.311 may be C(R.sub.311) or N, X.sub.312 may be C(R.sub.312) or N, X.sub.321 may be C(R.sub.321) or N, X.sub.322 may be C(R.sub.322) or N, X.sub.323 may be C(R.sub.323) or N, and X.sub.324 may be C(R.sub.324) or N, [0285] X.sub.41 may be C(R.sub.41) or N, X.sub.42 may be C(R.sub.42) or N, X.sub.43 may be C(R.sub.43) or N, and X.sub.44 may be C(R.sub.44) or N, [0286] R.sub.11 to R.sub.15 are each as described in connection with R.sub.1, [0287] R.sub.21 to R.sub.23 are each as described in connection with R.sub.2, [0288] R.sub.311, R.sub.312, and R.sub.321 to R.sub.324 are each as described in connection with R.sub.3, [0289] R.sub.41 to R.sub.44 are each as described in connection with R.sub.4, and [0290] two or more adjacent groups of R.sub.11 to R.sub.15, R.sub.21 to R.sub.23, R.sub.311, R.sub.312, R.sub.321 to R.sub.324, and R.sub.41 to R.sub.44 may optionally be bonded to each other to form a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a.

[0291] Unless defined otherwise, in Formula 1, R.sub.10a may be: [0292] deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; [0293] a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, or a C.sub.1-C.sub.60 alkoxy group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.11)(Q.sub.12)(Q.sub.13), N(Q.sub.11)(Q.sub.12), B(Q.sub.11)(Q.sub.12), C(O)(Q.sub.11), S(O).sub.2(Q.sub.11), P(O)(Q.sub.11)(Q.sub.12), or any combination thereof; [0294] a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.21)(Q.sub.22)(Q.sub.23), N(Q.sub.21)(Q.sub.22), B(Q.sub.21)(Q.sub.22), C(O)(Q.sub.21), S(O).sub.2(Q.sub.21), P(O)(Q.sub.21)(Q.sub.22), or any combination thereof; or [0295] O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), or P(O)(Q.sub.31)(Q.sub.32).

[0296] Unless defined otherwise, in Formula 1, Q.sub.1 to Q.sub.3, Q.sub.11 to Q.sub.13, Q.sub.21 to Q.sub.23, and Q.sub.31 to Q.sub.33 may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group; each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof; a C.sub.7-C.sub.60 arylakyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group.

[0297] In the organometallic compound represented by Formula 1, ring CY3 may include a moiety represented by Formula 1A. As the moiety represented by Formula 1A includes a bridged cyclic system, the - overlap may be reduced. Therefore, by using the organometallic compound represented by Formula 1, a light-emitting device (for example, an organic light-emitting device) having improved color purity and efficiency may be implemented.

Descriptions of Other Formulae

##STR00030##

[0298] In Formula 2, L.sub.51 to L.sub.53 may each independently be a single bond, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a.

[0299] In Formula 2, b51 to b53 indicate the number of L.sub.51 to L.sub.53, respectively, and may each be an integer from 1 to 5. When b51 is 2 or more, two or more of L.sub.51 may be substantially identical to or different from each other, if (e.g., when) b52 is 2 or more, two or more of L.sub.52 may be substantially identical to or different from each other, and if (e.g., when) b53 is 2 or more, two or more of L.sub.53 may be substantially identical to or different from each other. In one or more embodiments, b51 to b53 may each independently be 1 or 2.

[0300] In Formula 2, L.sub.51 to L.sub.53 may each independently be: [0301] a single bond; or [0302] a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a dibenzooxacilline group, a dibenzothiasiline group, a dibenzodihydroazasiline group, a dibenzodihydrodisiline group, a dibenzodihydrosiline group, a dibenzodioxane group, a dibenzooxathiene group, a dibenzooxazine group, a dibenzopyran group, a dibenzodithiin group, a dibenzothiazine group, a dibenzothiopyran group, a dibenzocyclohexadiene group, a dibenzodihydropyridine group, or a dibenzodihydropyrazine group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof, and [0303] Q.sub.31 to Q.sub.33 may each independently be hydrogen, deuterium, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group.

[0304] In one or more embodiments, in Formula 2, a bond between L.sub.51 and R.sub.51, a bond between L.sub.52 and R.sub.52, a bond between L.sub.53 and R.sub.53, a bond between two or more L.sub.51, a bond between two or more L.sub.52, a bond between two or more L.sub.53, a bond between L.sub.51 and carbon between X.sub.54 and X.sub.55 in Formula 2, a bond between L.sub.52 and carbon between X.sub.54 and X.sub.56 in Formula 2, and a bond between L.sub.53 and carbon between X.sub.55 and X.sub.56 in Formula 2 may each be a carbon-carbon single bond.

[0305] In Formula 2, X.sub.54 may be N or C(R.sub.54), X.sub.55 may be N or C(R.sub.55), and X.sub.56 may be N or C(R.sub.56), wherein at least one of X.sub.54 to X.sub.56 may be N. R.sub.54 to R.sub.56 are each as described herein. In one or more embodiments, two or three among X.sub.54 to X.sub.56 may each be N.

[0306] In Formula 2, R.sub.51 to R.sub.56 may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.7-C.sub.60 arylalkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 heteroarylalkyl group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2). Q.sub.1 to Q.sub.3 are each as described herein.

[0307] In Formula 2, R.sub.51 to R.sub.56 may each independently be:

[0308] hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; [0309] a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, Cl, Br, I, CDs, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.1 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof;

[0310] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, an azadibenzosilolyl group, or a group represented by Formula 91, each unsubstituted or substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzothiazolyl group, a benzoisoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof; or [0311] C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), and [0312] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: [0313] CH.sub.3, CD.sub.3, CD.sub.2H, CDH.sub.2, CH.sub.2CH.sub.3, CH.sub.2CD.sub.3, CH.sub.2CD.sub.2H, CH.sub.2CDH.sub.2, CHDCH.sub.3, CHDCD.sub.2H, CHDCDH.sub.2, CHDCD.sub.3, CD.sub.2CD.sub.3, CD.sub.2CD.sub.2H, or CD.sub.2CDH.sub.2; or [0314] an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.10 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof:

##STR00031## [0315] wherein, in Formula 91, [0316] ring CY.sub.91 and ring CY.sub.92 may each independently be a C.sub.5-C.sub.30 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.30 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0317] X.sub.91 may be a single bond, O, S, N(R.sub.91), B(R.sub.91), C(R.sub.91a)(R.sub.91b), or Si(R.sub.91a)(R.sub.91b), [0318] R.sub.91, R.sub.91a, and R.sub.91b are as described in connection with R.sub.82, R.sub.82a, and R.sub.82b, respectively, [0319] R.sub.10a is as described herein, and [0320] * indicates a binding site to a neighboring atom.

[0321] For example, in Formula 91, [0322] ring CY91 and ring CY92 may each independently be a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group, each unsubstituted or substituted with at least one R.sub.10a, and [0323] R.sub.91, R.sub.11a, and R.sub.91b may each independently be: [0324] hydrogen or a C.sub.1-C.sub.1 alkyl group; or [0325] a phenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.1 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof.

[0326] In Formula 2, a group represented by *-(L.sub.51).sub.b51-R.sub.51 and a group represented by *-(L.sub.52).sub.b52-R.sub.52 may each not be a phenyl group.

[0327] In one or more embodiments, a group represented by *-(L.sub.51).sub.b51-R.sub.51 and a group represented by *-(L.sub.52).sub.b52-R.sub.52 in Formula 2 may be substantially identical to each other.

[0328] In one or more embodiments, a group represented by *-(L.sub.51).sub.b51-R.sub.51 and a group represented by *-(L.sub.52).sub.b52-R.sub.52 in Formula 2 may be different from each other.

[0329] In one or more embodiments, in Formula 2, b51 and b52 may each be 1, 2, or 3, and L.sub.51 and L.sub.52 may each independently be a benzene group, a pyridine group, a pyrimidine group, a pyridazine group, a pyrazine group, or a triazine group, each unsubstituted or substituted with at least one R.sub.10a.

[0330] In one or more embodiments, R.sub.51 and R.sub.52 in Formula 2 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), or Si(Q.sub.1)(Q.sub.2)(Q.sub.3), and [0331] Q.sub.1 to Q.sub.3 may each independently be a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.

[0332] In one or more embodiments, a group represented by *-(L.sub.51).sub.b51-R.sub.51 in Formula 2 may be a group represented by one of Formulae CY51-1 to CY51-26, and/or [0333] a group represented by *-(L.sub.52).sub.b52-R.sub.52 in Formula 2 may be a group represented by one of Formulae CY52-1 to CY52-26, and/or [0334] a group represented by *-(L.sub.53).sub.b53-R.sub.53 in Formula 2 may be a group represented by one of (e.g., any one selected from among) Formulae CY53-1 to CY53-27, C(Q.sub.1)(Q.sub.2)(Q.sub.3), or Si(Q.sub.1)(Q.sub.2)(Q.sub.3):here

##STR00032## ##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042## ##STR00043##

##STR00044## ##STR00045## ##STR00046## [0335] wherein, in Formulae CY51-1 to CY51-26, CY52-1 to CY52-26, and CY53-1 to CY53-27, [0336] Y.sub.63 may be a single bond, O, S, N(R.sub.63), B(R.sub.63), C(R.sub.63a)(R.sub.63b), or Si(R.sub.63a)(R.sub.63b), [0337] Y.sub.64 may be a single bond, O, S, N(R.sub.64), B(R.sub.64), C(R.sub.64a)(R.sub.64b), or Si(R.sub.64a)(R.sub.64b), [0338] Y.sub.67 may be a single bond, O, S, N(R.sub.67), B(R.sub.67), C(R.sub.67a)(R.sub.67b), or Si(R.sub.67a)(R.sub.67b), [0339] Y.sub.68 may be a single bond, O, S, N(R.sub.68), B(R.sub.68), C(R.sub.68a)(R.sub.68b), or Si(R.sub.6sa)(R.sub.6sb), [0340] each of Y.sub.63 and Y.sub.64 in Formulae CY51-16 and CY51-17 may not be a single bond at the same time (e.g., simultaneously), [0341] each of Y.sub.67 and Y.sub.68 in Formulae CY52-16 and CY52-17 may not be a single bond at the same time (e.g., simultaneously), [0342] R.sub.51a to R.sub.51e, R.sub.61 to R.sub.64, R.sub.63a, R.sub.63b, R.sub.64a, and R.sub.64b are each as described in connection with R.sub.51, wherein R.sub.51a to R.sub.51e may each not be hydrogen, [0343] R.sub.52a to R.sub.52e, R.sub.65 to R.sub.68, R.sub.67a, R.sub.67b, R.sub.68a, and R.sub.68b are each as described in connection with R.sub.52, wherein R.sub.52a to R.sub.52e may each not be hydrogen, [0344] R.sub.53a to R.sub.53e, R.sub.69a, and R.sub.69b are each be as described in connection with R.sub.53, wherein R.sub.53a to R.sub.53e may each not be hydrogen, and [0345] * indicates a binding site to a neighboring atom.

[0346] In one or more embodiments, in Formulae CY51-1 to CY51-26 and CY52-1 to CY52-26, R.sub.51a to R.sub.51e and R.sub.52a to R.sub.52e may each independently be: [0347] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, an azadibenzosilolyl group, or a group represented by Formula 91, each unsubstituted or substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, or any combination thereof; or [0348] C(Q.sub.1)(Q.sub.2)(Q.sub.3) or Si(Q.sub.1)(Q.sub.2)(Q.sub.3), [0349] Q.sub.1 to Q.sub.3 may each independently be a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.10 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof, [0350] in Formulae CY51-16 and CY51-17, i) Y.sub.63 may be O or S, and Y.sub.64 may be Si(R.sub.64a)(R.sub.64b), or ii) Y.sub.63 may be Si(R.sub.63a)(R.sub.63b), and Y.sub.64 may be O or S, and [0351] in Formulae CY52-16 and CY52-17, i) Y.sub.67 may be O or S, and Yes may be Si(R.sub.68a)(R.sub.68b), or ii) Y.sub.67 may be Si(R.sub.67a)(R.sub.67b), and Yes may be O or S.

##STR00047##

[0352] In Formula 3, ring CY71 and ring CY72 may each independently be a electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group.

[0353] In Formula 3, X.sub.71 may be a single bond, or a linking group including O, S, N, B, C, Si, or any combination thereof.

[0354] In Formula 3, * indicates a binding site to any atom included in a remaining portion of the third compound other than the group represented by Formula 3.

##STR00048## ##STR00049##

[0355] In Formulae 3-1 to 3-5, ring CY71 to ring CY84 may each independently be a electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group.

[0356] In Formulae 3-1 to 3-5, X.sub.82 may be a single bond, O, S, N-[(L.sub.82).sub.b82-R.sub.82], C(R.sub.82a)(R.sub.82b), or Si(R.sub.82a)(R.sub.82b).

[0357] In Formulae 3-1 to 3-5, X.sub.83 may be a single bond, O, S, N-[(L.sub.83).sub.b83-R.sub.83], C(R.sub.83a)(R.sub.83b), or Si(R.sub.83a)(R.sub.83b).

[0358] In Formulae 3-1 to 3-5, X.sub.84 may be O, S, N-[(L.sub.84).sub.b84-R.sub.84], C(R.sub.84a)(R.sub.84b), or Si(R.sub.84a)(R.sub.84b).

[0359] In Formulae 3-1 to 3-5, X.sub.85 may be C or Si.

[0360] In Formulae 3-1 to 3-5, L.sub.81 to L.sub.85 may each independently be a single bond, *C(Q.sub.4)(Q.sub.5)-*, *Si(Q.sub.4)(Q.sub.5)-*, a electron-rich C.sub.3-C.sub.60 cyclic group unsubstituted or substituted with at least one R.sub.10a, or a pyridine group unsubstituted or substituted with at least one R.sub.10a.

[0361] Q.sub.4 and Q.sub.5 are each as described in connection with Q.sub.1.

[0362] In Formulae 3-1 to 3-5, b81 to b85 may each independently be an integer from 1 to 5.

[0363] In Formulae 3-1 to 3-5, R.sub.71 to R.sub.74, R.sub.81 to R.sub.85, R.sub.82a, R.sub.82b, R.sub.83a, R.sub.83b, R.sub.84a, and R.sub.84b are each as described herein.

[0364] In Formulae 3-1 to 3-5, a71 to a74 indicate the number of R.sub.71 to the number of R.sub.74, respectively, and may each independently be an integer from 0 to 20. When a71 is 2 or more, two or more of R.sub.71 may be substantially identical to or different from each other, if (e.g., when) a72 is 2 or more, two or more of R.sub.72 may be substantially identical to or different from each other, if (e.g., when) a73 is 2 or more, two or more of R.sub.73 may be substantially identical to or different from each other, and if (e.g., when) a74 is 2 or more, two or more of R.sub.74 may be substantially identical to or different from each other. a71 to a74 may each independently be an integer from 0 to 8.

[0365] R.sub.10a is as described herein.

[0366] In Formulae 3-1 to 3-5, L.sub.81 to L.sub.85 may each independently be: [0367] a single bond; [0368] *C(Q.sub.4)(Q)-* or *Si(Q.sub.4)(Q.sub.5)-*; or [0369] a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a furan group, a thiophene group, a silole group, an indene group, a fluorene group, an indole group, a carbazole group, a benzofuran group, a dibenzofuran group, a benzothiophene group, a dibenzothiophene group, a benzosilole group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, an azadibenzosilole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, or a benzothiadiazole group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a triazinyl group, a fluorenyl group, a dimethylfluorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a dimethyldibenzosilolyl group, a diphenyldibenzosilolyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof, and [0370] Q.sub.4, Q.sub.5, and Q.sub.31 to Q.sub.33 may each independently be hydrogen, deuterium, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group.

[0371] In one or more embodiments, a group represented by

##STR00050##

in Formulae 3-1 and 3-2 may be a group represented by one of (e.g., any one selected from among) Formulae CY71-1(1) to CY71-1(8), and/or [0372] a group represented by

##STR00051##

in Formulae 3-1 and 3-3 may be a group represented by one of (e.g., any one selected from among) Formulae CY71-2(1) to CY71-2(8), and/or [0373] a group represented by

##STR00052##

in Formulae 3-2 and 3-4 may be a group represented by one of (e.g., any one selected from among) Formulae CY71-3(1) to CY71-3(32), and/or [0374] a group represented by

##STR00053##

in Formulae 3-3 to 3-5 may be a group represented by one of (e.g., any one selected from among) Formulae CY71-4(1) to CY71-4(32), and/or [0375] a group represented by

##STR00054##

in Formula 3-5 may be a group represented by one of (e.g., any one selected from among) Formulae CY71-5(1) to CY71-5(8):

##STR00055## ##STR00056## ##STR00057## ##STR00058## ##STR00059## ##STR00060## ##STR00061##

##STR00062## ##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067## [0376] wherein, in Formulae CY71-1(1) to CY71-1(8), CY71-2(1) to CY71-2(8), CY71-3(1) to CY71-3(32), CY71-4(1) to CY71-4(32), and CY71-5(1) to CY71-5(8), [0377] X.sub.82 to X.sub.85, L.sub.81, b81, R.sub.81, and R.sub.85 are each as described herein, [0378] X.sub.86 may be a single bond, O, S, N(R.sub.86), B(R.sub.86), C(R.sub.86a)(R.sub.86b), or Si(R.sub.86a)(R.sub.86b), [0379] X.sub.87 may be a single bond, O, S, N(R.sub.87), B(R.sub.87), C(R.sub.87a)(R.sub.87b), or Si(R.sub.87a)(R.sub.87b), [0380] each of X.sub.86 and X.sub.87 in Formulae CY71-1(1) to CY71-1(8) and CY71-4(1) to CY71-4(32) may not be a single bond at the same time (e.g., simultaneously), [0381] X.sub.88 may be a single bond, O, S, N(R.sub.88), B(R.sub.88), C(R.sub.88a)(R.sub.88b), or Si(R.sub.88a)(R.sub.88b), [0382] X.sub.89 may be a single bond, O, S, N(R.sub.89), B(R.sub.89), C(R.sub.89a)(R.sub.89b), or Si(R.sub.89a)(R.sub.89b), [0383] each of X.sub.88 and X.sub.89 in Formulae CY71-2(1) to CY71-2(8), CY71-3(1) to CY71-3(32), and CY71-5(1) to CY71-5(8) may not be a single bond at the same time (e.g., simultaneously), and [0384] R.sub.86 to R.sub.89, R.sub.86a, R.sub.86b, R.sub.87a, R.sub.87b, R.sub.88a, R.sub.88b, R.sub.89a, and R.sub.89b are each as described in connection with R.sub.81.

##STR00068##

[0385] In Formulae 502 and 503, ring A.sub.501 to ring A.sub.504 may each independently be a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group.

[0386] In Formulae 502 and 503, Y.sub.505 may be O, S, N(R.sub.505), B(R.sub.505), C(R.sub.505a)(R.sub.505b), or Si(R.sub.505a)(R.sub.505b).

[0387] In Formulae 502 and 503, Y.sub.506 may be O, S, N(R.sub.506), B(R.sub.506), C(R.sub.506a)(R.sub.506b), or Si(R.sub.506a)(R.sub.506b).

[0388] In Formulae 502 and 503, Y.sub.507 may be O, S, N(R.sub.507), B(R.sub.507), C(R.sub.507a)(R.sub.507b), or Si(R.sub.507a)(R.sub.507b).

[0389] In Formulae 502 and 503, Y.sub.508 may be O, S, N(R.sub.508), B(R.sub.508), C(R.sub.508a)(R.sub.508b), or Si(R.sub.508a)(R.sub.508b).

[0390] In Formulae 502 and 503, Y.sub.51 and Y.sub.52 may each independently be B, P(O), or S(O).

[0391] In Formulae 502 and 503, R.sub.500a, R.sub.500b, R.sub.501 to R.sub.508, R.sub.505a, R.sub.505b, R.sub.506a, R.sub.506b, R.sub.507a, R.sub.507b, R.sub.508a, and R.sub.508b are each as described herein.

[0392] In Formulae 502 and 503, a501 to a504 indicate the number of R.sub.501 to the number of R.sub.504, respectively, and may each independently be an integer from 0 to 20. When a501 is 2 or more, two or more of R.sub.501 may be substantially identical to or different from each other, if (e.g., when) a502 is 2 or more, two or more of R.sub.502 may be substantially identical to or different from each other, if (e.g., when) a503 is 2 or more, two or more of R.sub.503 may be substantially identical to or different from each other, and if (e.g., when) a504 is 2 or more, two or more of R.sub.504 may be substantially identical to or different from each other. a501 to a504 may each independently be an integer from 0 to 8.

[0393] R.sub.51 to R.sub.56, R.sub.71 to R.sub.74, R.sub.81 to R.sub.85, R.sub.82a, R.sub.82b, R.sub.83a, R.sub.83b, R.sub.84a, R.sub.84b, R.sub.500a, R.sub.500b, R.sub.501 to R.sub.508, R.sub.505a, R.sub.505b, R.sub.506a, R.sub.506b, R.sub.507a, R.sub.507b, R.sub.508a, and R.sub.508b in the specification may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.6-C.sub.60 arylthio group unsubstituted or substituted with at least one R.sub.10a, a C.sub.7-C.sub.60 arylalkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 heteroaryl alkyl group unsubstituted or substituted with at least one R.sub.10a, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2). Q.sub.1 to Q.sub.3 are each as described herein.

[0394] In one or more embodiments, i) R.sub.51 to R.sub.56, R.sub.71 to R.sub.74, R.sub.81 to R.sub.85, R.sub.82a, R.sub.82b, R.sub.83a, R.sub.83b, R.sub.84a, R.sub.84b, R.sub.500a, R.sub.500b, R.sub.501 to R.sub.508, R.sub.505a, R.sub.505b, R.sub.506a, R.sub.506b, R.sub.507a, R.sub.507b, R.sub.508a, and R.sub.508b in Formulae 2, 3-1 to 3-5, 502, and 503 and ii) R.sub.10a may each independently be: [0395] hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, or a C.sub.1-C.sub.20 alkoxy group; [0396] a C.sub.1-C.sub.20 alkyl group or a C.sub.1-C.sub.20 alkoxy group, each substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.10 alkyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, or any combination thereof; [0397] a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azafluorenyl group, an azadibenzosilolyl group, or a group represented by Formula 91, each unsubstituted or substituted with deuterium, F, Cl, Br, I, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, CFH.sub.2, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, a phenyl group, a biphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, a naphthyl group, a fluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, an indolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzothiazolyl group, a benzoisoxazolyl group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, O(Q.sub.31), S(Q.sub.31), Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), P(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), P(O)(Q.sub.31)(Q.sub.32), or any combination thereof; or [0398] C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), N(Q.sub.1)(Q.sub.2), B(Q.sub.1)(Q.sub.2), C(O)(Q.sub.1), S(O).sub.2(Q.sub.1), or P(O)(Q.sub.1)(Q.sub.2), and [0399] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: [0400] CH.sub.3, CD.sub.3, CD.sub.2H, CDH.sub.2, CH.sub.2CH.sub.3, CH.sub.2CD.sub.3, CH.sub.2CD.sub.2H, CH.sub.2CDH.sub.2, CHDCH.sub.3, CHDCD.sub.2H, CHDCDH.sub.2, CHDCD.sub.3, CD.sub.2CD.sub.3, CD.sub.2CD.sub.2H, or CD.sub.2CDH.sub.2; or [0401] an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a phenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, or a triazinyl group, each unsubstituted or substituted with deuterium, a C.sub.1-C.sub.10 alkyl group, a phenyl group, a biphenyl group, a pyridinyl group, a pyrimidinyl group, a pyridazinyl group, a pyrazinyl group, a triazinyl group, or any combination thereof.

[0402] In one or more embodiments, i) R.sub.1 to R.sub.4 in Formula 1, ii) R.sub.51 to R.sub.56, R.sub.71 to R.sub.74, R.sub.81 to R.sub.85, R.sub.82a, R.sub.82b, R.sub.83a, R.sub.83b, R.sub.84a and R.sub.84b, R.sub.500a, R.sub.500b, R.sub.501 to R.sub.508, R.sub.505a, R.sub.505b, R.sub.506a, R.sub.506b, R.sub.507a, R.sub.507b, R.sub.508a, and R.sub.508b in Formulae 2, 3-1 to 3-5, 502, and 503, and iii) R.sub.10a may each independently be: [0403] hydrogen, deuterium, F, a cyano group, a nitro group, CH.sub.3, CD.sub.3, CD.sub.2H, CDH.sub.2, CF.sub.3, CF.sub.2H, or CFH.sub.2;

[0404] a group represented by one of (e.g., selected from among) Formulae 9-1 to 9-19; or [0405] a group represented by one of (e.g., selected from among) Formulae 10-1 to 10-246, C(Q.sub.1)(Q.sub.2)(Q.sub.3), Si(Q.sub.1)(Q.sub.2)(Q.sub.3), or P(O)(Q.sub.1)(Q.sub.2) (wherein Q.sub.1 to Q.sub.3 are each as described herein):

##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## [0406] wherein, in Formulae 9-1 to 9-19 and 10-1 to 10-246, * indicates a binding site to a neighboring atom, Ph represents a phenyl group, and TMS represents a trimethylsilyl group.

Examples of Compounds

[0407] In one or more embodiments, the organometallic compound represented by Formula 1 may be any one of (e.g., selected from among) Compounds 1 to 27:

##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110##

Description of FIG. 1

[0408] FIG. 1 is a schematic cross-sectional view of a light-emitting device 10 according to one or more embodiments. The light-emitting device 10 includes a first electrode 110, an interlayer 130, and a second electrode 150. Hereinafter, a structure of the light-emitting device 10 according to one or more embodiments and a method of manufacturing the light-emitting device 10 are described with reference to FIG. 1.

First Electrode 110

[0409] In FIG. 1, a substrate may be additionally arranged under the first electrode 110 or on the second electrode 150. As the substrate, a glass substrate or a plastic substrate may be used. In one or more embodiments, the substrate may be a flexible substrate and may include plastics with excellent or suitable heat resistance and durability, such as polyimide, polyethylene terephthalate (PET), polycarbonate, polyethylene naphthalate, polyarylate (PAR), polyetherimide, or any combination thereof.

[0410] The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high-work function material that facilitates injection of holes.

[0411] The first electrode 110 may be a reflective electrode, a transflective electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO.sub.2), zinc oxide (ZnO), or any combination thereof. In one or more embodiments, if (e.g., when) the first electrode 110 is a transflective electrode or a reflective electrode, a material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (AI), aluminum-lithium (AlLi), calcium (Ca), magnesium-indium (MgIn), magnesium-silver (Mg-Ag), or any combination thereof.

[0412] The first electrode 110 may have a single-layer structure including (e.g., consisting of) a single layer or a multilayer structure including a plurality of layers. In one or more embodiments, the first electrode 110 may have a three-layer structure of ITO/Ag/ITO.

Interlayer 130

[0413] The interlayer 130 may be arranged above the first electrode 110. The interlayer 130 includes the emission layer.

[0414] The interlayer 130 may further include a hole transport region arranged between the first electrode 110 and the emission layer, and an electron transport region arranged between the emission layer and the second electrode 150.

[0415] The interlayer 130 may further include, in addition to one or more suitable organic materials, a metal-containing compound such as an organometallic compound, an inorganic material such as quantum dots, and/or the like.

[0416] In one or more embodiments, the interlayer 130 may include, i) two or more emitting units sequentially stacked between the first electrode 110 and the second electrode 150, and ii) a charge generation layer between the two or more emitting units. When the interlayer 130 includes emitting units and a charge generation layer as described herein, the light-emitting device 10 may be a tandem light-emitting device.

Hole Transport Region in Interlayer 130

[0417] The hole transport region may have: i) a single-layer structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layer structure including (e.g., consisting of) a single layer including (e.g., consisting of) a plurality of materials that are different from each other, or iii) a multilayer structure including a plurality of layers including a plurality of materials that are different from each other.

[0418] The hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.

[0419] For example, the hole transport region may have a multi-layer structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron-blocking layer structure, wherein layers in each structure are sequentially stacked from the first electrode 110.

[0420] The hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, and/or any combination thereof:

##STR00111## [0421] wherein, in Formulae 201 and 202, [0422] L.sub.201 to L.sub.204 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0423] L.sub.205 may be *O*, *S*, *N(Q.sub.201)-*, a C.sub.1-C.sub.20 alkylene group unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.20 alkenylene group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0424] xa1 to xa4 may each independently be an integer from 0 to 5, [0425] xa5 may be an integer from 1 to 10, [0426] R.sub.201 to R.sub.204 and Q.sub.201 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0427] R.sub.201 and R.sub.202 may optionally be linked to each other via a single bond, a C.sub.1-C.sub.5 alkylene group unsubstituted or substituted with at least one R.sub.10a, or a C.sub.2-C.sub.5 alkenylene group unsubstituted or substituted with at least one R.sub.10a to form a C.sub.8-C.sub.60 polycyclic group (e.g., a carbazole group and/or the like) unsubstituted or substituted with at least one R.sub.10a (e.g., see Compound HT16), [0428] R.sub.203 and R.sub.204 may optionally be linked to each other via a single bond, a C.sub.1-C.sub.5 alkylene group that is unsubstituted or substituted with at least one R.sub.10a, or a C.sub.2-C.sub.5 alkenylene group that is unsubstituted or substituted with at least one R.sub.10a to form a C.sub.8-C.sub.60 polycyclic group that is unsubstituted or substituted with at least one R.sub.10a, and [0429] na1 may be an integer from 1 to 4.

[0430] In one or more embodiments, each of Formulae 201 and 202 may include at least one of (e.g., at least one selected from among) groups represented by Formulae CY201 to CY217:

##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## [0431] wherein, in Formulae CY201 to CY217, R.sub.10b, and R.sub.10c are each as described in connection with R.sub.10a, ring CY201 to ring CY204 may each independently be a C.sub.3-C.sub.20 carbocyclic group or a C.sub.1-C.sub.20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R.sub.10a.

[0432] In one or more embodiments, ring CY201 to ring CY204 in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.

[0433] In one or more embodiments, each of Formulae 201 and 202 may include at least one of (e.g., at least one selected from among) groups represented by Formulae CY201 to CY203.

[0434] In one or more embodiments, Formula 201 may include at least one of (e.g., at least one selected from among) groups represented by Formulae CY201 to CY203 and at least one of (e.g., at least one selected from among) groups represented by Formulae CY204 to CY217.

[0435] In one or more embodiments, in Formula 201, xa1 may be 1, R.sub.201 may be a group represented by one of (e.g., at least one selected from among) Formulae CY201 to CY203, xa2 may be 0, and R.sub.202 may be a group represented by one of (e.g., at least one selected from among) Formulae CY204 to CY207.

[0436] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude any of) groups represented by Formulae CY201 to CY203.

[0437] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude any of) groups represented by Formulae CY201 to CY203 and may include at least one of groups represented by Formulae CY204 to CY217.

[0438] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude any of) groups represented by Formulae CY201 to CY217.

[0439] In one or more embodiments, the hole transport region may include one of (e.g., any one selected from among) Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB(NPD), -NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4,4-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate) (PANI/PSS), and/or any combination thereof:

##STR00119## ##STR00120## ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127## ##STR00128## ##STR00129##

[0440] The thickness of the hole transport region may be about 50 angstrom () to about 10,000 , for example, about 100 to about 4,000 . When the hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, the thickness of the hole injection layer may be about 100 to about 9,000 , for example, about 100 to about 1,000 , and the thickness of the hole transport layer may be about 50 to about 2,000 , for example, about 100 to about 1,500 . When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within the ranges described herein, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

[0441] The emission auxiliary layer may increase light emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by the emission layer, and the electron blocking layer may block or reduce the leakage of electrons from the emission layer to the hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron blocking layer.

p-Dopant

[0442] The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly (e.g., substantially uniformly) or non-uniformly (e.g., substantially non-uniformly) dispersed in the hole transport region (for example, in the form of a single layer including (e.g., consisting of) a charge-generation material).

[0443] The charge-generation material may be, for example, a p-dopant (e.g., p type charge-generation material).

[0444] For example, the LUMO energy level of the p-dopant may be less than or equal to 3.5 electron volt (eV).

[0445] In one or more embodiments, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including an element EL1 and an element EL2, or any combination thereof.

[0446] Examples of the quinone derivative may include TCNQ and/or F4-TCNQ.

[0447] Examples of the cyano group-containing compound may include HAT-CN and/or a compound represented by Formula 221:

##STR00130## [0448] wherein, in Formula 221, [0449] R.sub.221 to R.sub.223 may each independently be a C.sub.3-C.sub.60 carbocyclic group that is unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group that is unsubstituted or substituted with at least one R.sub.10a, and [0450] at least one of R.sub.221 to R.sub.223 may each independently be a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each substituted with: a cyano group; F; C.sub.1; Br; I; a C.sub.1-C.sub.20 alkyl group substituted with a cyano group, F, Cl, Br, I, or any combination thereof; or any combination thereof.

[0451] In the compound including the element EL1 and the element EL2, the element EL1 may be a metal, a metalloid, and/or a (e.g., any suitable) combination thereof, and the element EL2 may be a non-metal, a metalloid, and/or a (e.g., any suitable) combination thereof.

[0452] Examples of the metal may include an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and/or the like); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and/or the like); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), and/or the like); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), and/or the like); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and/or the like).

[0453] Examples of the metalloid may include silicon (Si), antimony (Sb), and tellurium (Te).

[0454] Examples of the non-metal may include oxygen (O) and halogen (for example, F, Cl, Br, I, and/or the like).

[0455] Examples of the compound including the element EL1 and the element EL2 may include a metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, a metal iodide, and/or the like), a metalloid halide (for example, a metalloid fluoride, a metalloid chloride, a metalloid bromide, a metalloid iodide, and/or the like), a metal telluride, or any combination thereof.

[0456] Examples of the metal oxide may include a tungsten oxide (for example, WO, W.sub.2O.sub.3, WO.sub.2, WO.sub.3, W.sub.2O.sub.5, and/or the like), a vanadium oxide (for example, VO, V.sub.2O.sub.3, VO.sub.2, V.sub.2O.sub.5, and/or the like), a molybdenum oxide (for example, MoO, Mo.sub.2O.sub.3, MoO.sub.2, MoO.sub.3, Mo.sub.2O.sub.5, and/or the like), and a rhenium oxide (for example, ReO.sub.3, and/or the like).

[0457] Examples of the metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, and a lanthanide metal halide.

[0458] Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, and CsI.

[0459] Examples of the alkaline earth metal halide may include BeF.sub.2, MgF.sub.2, CaF.sub.2, SrF.sub.2, BaF.sub.2, BeCl.sub.2, MgCl.sub.2, CaCl.sub.2), SrCl.sub.2, BaCl.sub.2, BeBr.sub.2, MgBr.sub.2, CaBr.sub.2, SrBr.sub.2, BaBr.sub.2, BeI.sub.2, MgI.sub.2, CaI.sub.2, SrI.sub.2, and BaI.sub.2.

[0460] Examples of the transition metal halide may include a titanium halide (for example, TiF.sub.4, TiC.sub.4, TiBr.sub.4, TiI.sub.4, and/or the like), a zirconium halide (for example, ZrF.sub.4, ZrCl.sub.4, ZrBr.sub.4, ZrI.sub.4, and/or the like), a hafnium halide (for example, HfF.sub.4, HfCl.sub.4, HfBr.sub.4, HfI.sub.4, and/or the like), a vanadium halide (for example, VF.sub.3, VCl.sub.3, VBr.sub.3, VI.sub.3, and/or the like), a niobium halide (for example, NbF.sub.3, NbCI.sub.3, NbBr.sub.3, NbI.sub.3, and/or the like), a tantalum halide (for example, TaF.sub.3, TaCl.sub.3, TaBr.sub.3, TaI.sub.3, and/or the like), a chromium halide (for example, CrF.sub.3, CrCl.sub.3, CrBr.sub.3, CrI.sub.3, and/or the like), a molybdenum halide (for example, MoF.sub.3, MoCl.sub.3, MoBr.sub.3, MoI.sub.3, and/or the like), a tungsten halide (for example, WF.sub.3, WCl.sub.3, WBr.sub.3, WI.sub.3, and/or the like), a manganese halide (for example, MnF.sub.2, MnCl.sub.2, MnBr.sub.2, MnI.sub.2, and/or the like), a technetium halide (for example, TcF.sub.2, TcCl.sub.2, TcBr.sub.2, TcI.sub.2, and/or the like), a rhenium halide (for example, ReF.sub.2, ReCl.sub.2, ReBr.sub.2, ReI.sub.2, and/or the like), an Iron(II) halide (for example, FeF.sub.2, FeCl.sub.2, FeBr.sub.2, FeI.sub.2, and/or the like), a ruthenium halide (for example, RuF.sub.2, RuCl.sub.2, RuBr.sub.2, RuI.sub.2, and/or the like), an osmium halide (for example, OsF.sub.2, OsCl.sub.2, OsBr.sub.2, OsI.sub.2, and/or the like), a cobalt halide (for example, CoF.sub.2, COCl.sub.2, CoBr.sub.2, CoI.sub.2, and/or the like), a rhodium halide (for example, RhF.sub.2, RhCl.sub.2, RhBr.sub.2, RhI.sub.2, and/or the like), an iridium halide (for example, IrF.sub.2, IrCl.sub.2, IrBr.sub.2, IrI.sub.2, and/or the like), a nickel halide (for example, NiF.sub.2, NiCl.sub.2, NiBr.sub.2, NiI.sub.2, and/or the like), a palladium halide (for example, PdF.sub.2, PdCl.sub.2, PdBr.sub.2, PdI.sub.2, and/or the like), a platinum halide (for example, PtF.sub.2, PtCl.sub.2, PtBr.sub.2, Pt.sub.12, and/or the like), a Copper(I) halide (for example, CuF, CuCl, CuBr, CuI, and/or the like), a silver halide (for example, AgF, AgCl, AgBr, AgI, and/or the like), and a gold halide (for example, AuF, AuCl, AuBr, AuI, and/or the like).

[0461] Examples of the post-transition metal halide may include a zinc halide (for example, ZnF.sub.2, ZnCl.sub.2, ZnBr.sub.2, ZnI.sub.2, and/or the like), an indium halide (for example, InI.sub.3, and/or the like), and a tin halide (for example, SnI.sub.2, and/or the like).

[0462] Examples of the lanthanide metal halide may include YbF, YbF.sub.2, YbF.sub.3, SmF.sub.3, YbCl, YbCl.sub.2, YbCl.sub.3, SmCl.sub.3, YbBr, YbBr.sub.2, YbBr.sub.3, SmBr.sub.3, YbI, YbI.sub.2, YbI.sub.3, SmI.sub.3, and/or the like.

[0463] Examples of the metalloid halide may include an antimony halide (for example, SbCI.sub.5, and/or the like).

[0464] Examples of the metal telluride may include an alkali metal telluride (for example, Li.sub.2Te, Na.sub.2Te, K.sub.2Te, Rb.sub.2Te, Cs.sub.2Te, and/or the like), an alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, and/or the like), a transition metal telluride (for example, TiTe.sub.2, ZrTe.sub.2, HfTe.sub.2, V.sub.2Te.sub.3, Nb.sub.2Te.sub.3, Ta.sub.2Te.sub.3, Cr.sub.2Te.sub.3, Mo.sub.2Te.sub.3, W.sub.2Te.sub.3, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu.sub.2Te, CuTe, Ag.sub.2Te, AgTe, Au.sub.2Te, and/or the like), a post-transition metal telluride (for example, ZnTe, and/or the like), and a lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, and/or the like).

Emission Layer in Interlayer 130

[0465] When the light-emitting device 10 is a full-color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer may have a stacked structure of two or more layers of a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other, to emit white light. In one or more embodiments, the emission layer may include two or more materials of a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer, to emit white light.

[0466] In one or more embodiments, the emission layer may include a host and a dopant (or an emitter). In one or more embodiments, the emission layer may further include an auxiliary dopant that promotes energy transfer to a dopant (or an emitter), in addition to the host and the dopant (or an emitter). When the emission layer includes the dopant (or an emitter) and the auxiliary dopant, the dopant (or an emitter) and the auxiliary dopant are different from each other.

[0467] The organometallic compound represented by Formula 1 in the specification may serve as the dopant (or an emitter), or may serve as the auxiliary dopant.

[0468] An amount (weight) of the dopant (or an emitter) in the emission layer may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host.

[0469] In one or more embodiments, the emission layer may include the organometallic compound represented by Formula 1. An amount of the organometallic compound in the emission layer may be, based on 100 parts by weight of the organometallic compound, in a range of about 0.01 parts by weight to about 30 parts by weight, about 0.1 parts by weight to about 20 parts by weight, or about 0.1 parts by weight to about 15 parts by weight.

[0470] In one or more embodiments, the emission layer may include a quantum dot.

[0471] In one or more embodiments, the emission layer may include a delayed fluorescence material. The delayed fluorescence material may act as a host or a dopant in the emission layer.

[0472] The thickness of the emission layer may be about 100 A to about 1,000 , for example, about 200 A to about 600 . When the thickness of the emission layer is within the range described herein, excellent or suitable luminescence characteristics may be obtained without a substantial increase in driving voltage.

Host

[0473] In one or more embodiments, the host in the emission layer may include the second compound, the third compound, or any combination thereof.

[0474] In one or more embodiments, the host may include a compound represented by Formula 301:

##STR00131## [0475] wherein, in Formula 301, [0476] Ar.sub.301 and L.sub.301 may each independently be a C.sub.3-C.sub.60 carbocyclic group that is unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group that is unsubstituted or substituted with at least one R.sub.10a, [0477] xb11 may be 1, 2, or 3, [0478] xb1 may be an integer from 0 to 5, [0479] R.sub.301 may be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkenyl group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.2-C.sub.60 alkynyl group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 alkoxy group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group that is unsubstituted or substituted with at least one R.sub.10a, Si(Q.sub.301)(Q.sub.302)(Q.sub.303), N(Q.sub.301)(Q.sub.302), B(Q.sub.301)(Q.sub.302), C(O)(Q.sub.301), S(O).sub.2(Q.sub.301), or P(O)(Q.sub.301)(Q.sub.302), [0480] xb21 may be an integer from 1 to 5, and [0481] Q.sub.301 to 0303 are each as described in connection with Q.sub.1.

[0482] In one or more embodiments, if (e.g., when) xb11 in Formula 301 is 2 or more, two or more of Ar.sub.301 may be linked to each other via a single bond.

[0483] In one or more embodiments, the host may include a compound represented by Formula 301-1, a compound represented by Formula 301-2, or any combination thereof:

##STR00132## [0484] wherein, in Formulae 301-1 and 301-2, [0485] ring A.sub.301 to ring A.sub.304 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0486] X.sub.301 may be O, S, N-[(L.sub.304).sub.xb4-R.sub.304], C(R.sub.304)(R.sub.305), or Si(R.sub.304)(R.sub.305), [0487] xb22 and xb23 may each independently be 0, 1, or 2, [0488] L.sub.301, xb1, and R.sub.301 are each as described in the specification, [0489] L.sub.302 to L.sub.304 may each independently be as described in connection with L.sub.301, [0490] xb2 to xb4 may each independently be as described in connection with xb1, and

[0491] R.sub.302 to R.sub.305 and R.sub.311 to R.sub.314 are each as described in connection with R.sub.301.

[0492] In one or more embodiments, the host may include an alkaline earth metal complex, a post-transition metal complex, or any combination thereof. In one or more embodiments, the host may include a Be complex (for example, Compound H55), an Mg complex, a Zn complex, or any combination thereof.

[0493] In one or more embodiments, the host may include: any one of (e.g., selected from among) Compounds H1 to H128; 9,10-di(2-naphthyl)anthracene (ADN); 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN); 9,10-di(2-naphthyl)-2-t-butyl-anthracene (TBADN); 4,4-bis(N-carbazolyl)-1,1-biphenyl (CBP); 1,3-di(carbazol-9-yl)benzene (mCP); 1,3,5-tri(carbazol-9-yl)benzene (TCP); and/or any combination thereof:

##STR00133## ##STR00134## ##STR00135## ##STR00136## ##STR00137## ##STR00138## ##STR00139## ##STR00140## ##STR00141## ##STR00142## ##STR00143## ##STR00144## ##STR00145## ##STR00146## ##STR00147## ##STR00148## ##STR00149## ##STR00150## ##STR00151## ##STR00152## ##STR00153## ##STR00154## ##STR00155## ##STR00156## ##STR00157## ##STR00158## ##STR00159## ##STR00160## ##STR00161## ##STR00162## ##STR00163##

##STR00164##

[0494] In one or more embodiments, the host may include a silicon-containing compound, a phosphine oxide-containing compound, or any combination thereof.

[0495] The host may have one or more suitable modifications. For example, the host may include only one kind of compound, or may include two or more kinds of different compounds.

Phosphorescent Dopant

[0496] The emission layer may include, as a phosphorescent dopant, the organometallic compound represented by Formula 1.

[0497] In one or more embodiments, if (e.g., when) the emission layer includes the organometallic compound represented by Formula 1 and the organometallic compound represented by Formula 1 serves as an auxiliary dopant, the emission layer may include a phosphorescent dopant.

[0498] The phosphorescent dopant may include at least one transition metal as a central metal.

[0499] The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof.

[0500] The phosphorescent dopant may be electrically neutral.

[0501] In one or more embodiments, the phosphorescent dopant may include an organometallic compound represented by Formula 401:

##STR00165## [0502] wherein, in Formulae 401 and 402, [0503] M may be a transition metal (e.g., Ir, Pt, Pd, Os, Ti, Au, Hf, Eu, Tb, Rh, Re, or Tm), [0504] L.sub.401 may be a ligand represented by Formula 402, and xc1 is 1, 2, or 3, wherein, if (e.g., when) xc1 is 2 or more, two or more of L.sub.401 may be substantially identical to or different from each other, [0505] L.sub.402 may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, wherein, if (e.g., when) xc2 is 2 or more, two or more of L.sub.402 may be substantially identical to or different from each other, [0506] X.sub.401 and X.sub.402 may each independently be nitrogen or carbon, [0507] ring A.sub.401 and ring A.sub.402 may each independently be a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, [0508] T.sub.401 may be a single bond, *O*, *S*, *C(O)*, *N(Q.sub.411)-*, *C(Q.sub.411)(Q.sub.412)-*, *C(Q.sub.411)C(Q.sub.412)-*, *C(Q.sub.411)*, or *C*, [0509] X.sub.403 and X.sub.404 may each independently be a chemical bond (for example, a covalent bond or a coordinate bond), O, S, N(Q.sub.413), B(Q.sub.413), P(Q.sub.413), C(Q.sub.413)(Q.sub.414), or Si(Q.sub.413)(Q.sub.414), [0510] Q.sub.411 to Q.sub.414 are each as described in connection with Q.sub.1, [0511] R.sub.401 and R.sub.402 may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.20 alkoxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, Si(Q.sub.401)(Q.sub.402)(Q.sub.403), N(Q.sub.401)(Q.sub.402), B(Q.sub.401)(Q.sub.402), C(O)(Q.sub.401), S(O).sub.2(Q.sub.401), or P(O)(Q.sub.401)(Q.sub.402), [0512] Q.sub.401 to Q.sub.403 are each as described in connection with Q.sub.1, [0513] xc11 and xc12 may each independently be an integer from 0 to 10, and [0514] * and * in Formula 402 each indicate a binding site to M in Formula 401.

[0515] In one or more embodiments, in Formula 402, i) X.sub.401 may be nitrogen, and X.sub.4O.sub.2 may be carbon, or ii) each of X.sub.401 and X.sub.402 may be nitrogen.

[0516] In one or more embodiments, if (e.g., when) xc1 in Formula 401 is 2 or more, two ring A.sub.401 selected from among two or more of L.sub.401 may be optionally linked together via T.sub.402, which is a linking group, and two ring A.sub.402 may be optionally linked together via T.sub.403, which is a linking group (see Compounds PD1 to PD4 and PD7). T.sub.402 and T.sub.403 are each as described in connection with T.sub.401.

[0517] L.sub.402 in Formula 401 may be an organic ligand. In one or more embodiments, L.sub.402 may include a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), C(O), an isonitrile group, a CN group, a phosphorus-containing group (for example, a phosphine group, a phosphite group, and/or the like), or any combination thereof.

[0518] The phosphorescent dopant may include, for example, at least one of (e.g., selected from among) compounds PD1 to PD39, or a (e.g., any) combination thereof:

##STR00166## ##STR00167## ##STR00168## ##STR00169## ##STR00170## ##STR00171## ##STR00172## ##STR00173##

Fluorescent Dopant

[0519] In one or more embodiments, if (e.g., when) the emission layer includes the organometallic compound represented by Formula 1 and the organometallic compound represented by Formula 1 serves as an auxiliary dopant, the emission layer may further include a fluorescent dopant.

[0520] In one or more embodiments, if (e.g., when) the emission layer includes the organometallic compound represented by Formula 1 and the organometallic compound represented by Formula 1 serves as a phosphorescent dopant, the emission layer may further include an auxiliary dopant.

[0521] The fluorescent dopant and the auxiliary dopant may each independently include an arylamine compound, a styrylamine compound, a boron-containing compound, or any combination thereof.

[0522] In one or more embodiments, the fluorescent dopant and the auxiliary dopant may each independently include a compound represented by Formula 501:

##STR00174## [0523] wherein, in Formula 501, [0524] Ar.sub.501, L.sub.501 to L.sub.503, R.sub.501, and R.sub.502 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0525] xd1 to xd3 may each independently be 0, 1, 2, or 3, and [0526] xd4 may be 1, 2, 3, 4, 5, or 6.

[0527] In one or more embodiments, Ar.sub.501 in Formula 501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, a pyrene group, and/or the like) in which three or more monocyclic groups are condensed together.

[0528] In one or more embodiments, xd4 in Formula 501 may be 2.

[0529] In one or more embodiments, the fluorescent dopant and the auxiliary dopant may each include: at least one of (e.g., selected from among) Compounds FD1 to FD37; DPVBi; DPAVBi; and/or any combination thereof:

##STR00175## ##STR00176## ##STR00177## ##STR00178## ##STR00179##

Delayed Fluorescence Material

[0530] The emission layer may include a delayed fluorescence material.

[0531] Herein, the delayed fluorescence material may be selected from among compounds capable of emitting delayed fluorescence based on a delayed fluorescence emission mechanism.

[0532] The delayed fluorescence material may include, for example, the fourth compound described herein.

[0533] The delayed fluorescence material included in the emission layer may act as a host or a dopant depending on the type or kind of other materials included in the emission layer.

[0534] In one or more embodiments, a difference between a triplet energy level (eV) of the delayed fluorescence material and a singlet energy level (eV) of the delayed fluorescence material may be at least 0 eV but not more than 0.5 eV. When the difference between the triplet energy level (eV) of the delayed fluorescence material and the singlet energy level (eV) of the delayed fluorescence material is within the range described herein, up-conversion from the triplet state to the singlet state of the delayed fluorescence material may effectively occur, and thus, the light-emitting device 10 may have improved luminescence efficiency.

[0535] In one or more embodiments, the delayed fluorescence material may include: i) a material including at least one electron donor (for example, a electron-rich C.sub.3-C.sub.60 cyclic group such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, a electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group, and/or the like), ii) a material including a C.sub.8-C.sub.60 polycyclic group including at least two cyclic groups that are condensed with each other while sharing boron (B).

[0536] Examples of the delayed fluorescence material may include at least one of (e.g., selected from among) Compounds DF1 to DF14:

##STR00180## ##STR00181## ##STR00182##

Quantum Dot

[0537] The emission layer may include a quantum dot.

[0538] The term quantum dot as used herein refers to a crystal of a semiconductor compound, and may include any material capable of emitting light of one or more suitable emission wavelengths according to the size of the crystal.

[0539] A diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm. In the present disclosure, when quantum dot, quantum dots, or quantum dot particles are spherical, diameter indicates a particle diameter or an average particle diameter, and when the particles are non-spherical, the diameter indicates a major axis length or an average major axis length. The diameter of the particles may be measured utilizing a scanning electron microscope or a particle size analyzer. As the particle size analyzer, for example, HORIBA, LA-950 laser particle size analyzer, may be utilized. When the size of the particles is measured utilizing a particle size analyzer, the average particle diameter is referred to as D50. D50 refers to the average diameter of particles whose cumulative volume corresponds to 50 vol % in the particle size distribution (e.g., cumulative distribution), and refers to the value of the particle size corresponding to 50% from the smallest particle when the total number of particles is 100% in the distribution curve accumulated in the order of the smallest particle size to the largest particle size.

[0540] The quantum dot may be synthesized by a wet chemical process, a metal organic chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto.

[0541] The wet chemical process is a method including mixing a precursor material with an organic solvent and then growing a quantum dot particle crystal. When the quantum dot particle crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot particle crystal and controls the growth of the crystal so that the growth of quantum dot particle crystals can be controlled or selected through a process which costs lower, and is easier than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE).

[0542] The quantum dot may include Group II-VI semiconductor compounds, Group III-V semiconductor compounds, Group III-VI semiconductor compounds, Group I-III-VI semiconductor compounds, Group IV-VI semiconductor compounds, a Group IV element or compound, and/or a (e.g., any suitable) combination thereof.

[0543] Examples of the Group II-VI semiconductor compound are a binary compound, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; and/or a (e.g., any suitable) combination thereof.

[0544] Examples of the Group III-V semiconductor compound are: a binary compound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and/or the like; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, and/or the like; a quaternary compound, such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GalnNSb, GaInPAs, GalnPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and/or the like; or any combination thereof. In one or more embodiments, the Group III-V semiconductor compound may further include a Group II element. Examples of the Group III-V semiconductor compound further including a Group II element are InZnP, InGaZnP, InAlZnP, and/or the like.

[0545] Examples of the Group III-VI semiconductor compound are: a binary compound, such as GaS, GaSe, Ga.sub.2Se.sub.3, GaTe, InS, InSe, In.sub.2S.sub.3, In.sub.2Se.sub.3, or InTe; a ternary compound, such as InGaS.sub.3, or InGaSe.sub.3; and/or a (e.g., any suitable) combination thereof.

[0546] Examples of the Group I-III-VI semiconductor compound are: a ternary compound, such as AgInS, AgInS.sub.2, CuInS, CuInS.sub.2, CuGaO.sub.2, AgGaO.sub.2, AgAlO.sub.2, and/or the like; or any combination thereof.

[0547] Examples of the Group IV-VI semiconductor compound are: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, or SnPbSTe; and/or a (e.g., any suitable) combination thereof.

[0548] The Group IV element or compound may include: a single element, such as Si or Ge; a binary compound, such as SiC or SiGe; and/or a (e.g., any suitable) combination thereof.

[0549] Each element included in a multi-element compound such as the binary compound, the ternary compound, and the quaternary compound may be present at a substantially uniform concentration or substantially non-uniform concentration in a particle.

[0550] In one or more embodiments, the quantum dot may have a single structure in which the concentration of each element in the quantum dot is substantially uniform, or a core-shell dual structure. For example, the material included in the core and the material included in the shell may be different from each other.

[0551] The shell of the quantum dot may act as a protective layer that prevents chemical degeneration of the core to maintain semiconductor characteristics, and/or as a charging layer that imparts electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. The interface between the core and the shell may have a concentration gradient in which the concentration of an element existing in the shell decreases toward the center of the core.

[0552] Examples of the shell of the quantum dot may be an oxide of metal, metalloid, or non-metal, a semiconductor compound, and/or a (e.g., any suitable) combination thereof. Examples of the oxide of metal, metalloid, or non-metal are a binary compound, such as SiO.sub.2, Al.sub.2O.sub.3, TiO.sub.2, ZnO, MnO, Mn.sub.2O.sub.3, Mn.sub.3O.sub.4, CuO, FeO, Fe.sub.2O.sub.3, Fe.sub.3O.sub.4, CoO, Co.sub.3O.sub.4, or NiO; a ternary compound, such as MgAl.sub.2O.sub.4, CoFe.sub.2O.sub.4, NiFe.sub.2O.sub.4, or CoMn.sub.2O.sub.4; and/or a (e.g., any suitable) combination thereof. Examples of the semiconductor compound are, as described herein, a Group II-VI semiconductor compound; a Group III-V semiconductor compound; a Group III-VI semiconductor compound; a Group I-III-VI semiconductor compound; a Group IV-VI semiconductor compound; and/or a (e.g., any suitable) combination thereof. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, and/or a (e.g., any suitable) combination thereof.

[0553] A full width at half maximum (FWHM) of the emission wavelength spectrum of the quantum dot may be about 45 nanometer (nm) or less, for example, about 40 nm or less, for example, about 30 nm or less, and within these ranges, color purity or color reproducibility may be increased. In some embodiments, because the light emitted through the quantum dot is emitted in all directions, the wide viewing angle may be improved.

[0554] In some embodiments, the quantum dot may be in the form of a spherical nanoparticle, a pyramidal nanoparticle, a multi-arm nanoparticle, a cubic nanoparticle, a nanotube, a nanowire, a nanofiber, or a nanoplate.

[0555] Because an energy band gap may be adjusted by controlling the size of the quantum dot, light having one or more suitable wavelength bands may be obtained from the quantum dot emission layer. Accordingly, by using quantum dots of different sizes, a light-emitting device that emits light of one or more suitable wavelengths may be implemented. In one or more embodiments, the size of the quantum dot may be selected to emit red, green and/or blue light. In some embodiments, the size of the quantum dot may be configured to emit white light by combination of light of one or more suitable colors.

Electron Transport Region in Interlayer 130

[0556] The electron transport region may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including multiple different materials, or iii) a multilayer structure including multiple layers including multiple different materials.

[0557] The electron transport region may include a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof.

[0558] For example, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein layers in each structure are sequentially stacked from the emission layer.

[0559] The electron transport region (e.g., a buffer layer, a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound including at least one electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

[0560] In one or more embodiments, the electron transport region may include a compound represented by Formula 601.

##STR00183##

wherein, in Formula 601, [0561] Ar.sub.601 and L.sub.601 may each independently be a C.sub.3-C.sub.60 carbocyclic group unsubstituted or substituted with at least one R.sub.10a or a C.sub.1-C.sub.60 heterocyclic group unsubstituted or substituted with at least one R.sub.10a, [0562] xe11 may be 1, 2, or 3, [0563] xe1 may be 0, 1, 2, 3, 4, or 5, [0564] R.sub.601 may be a C.sub.3-C.sub.60 carbocyclic group that is unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-C.sub.60 heterocyclic group that is unsubstituted or substituted with at least one R.sub.10a, Si(Q.sub.601)(Q.sub.602)(Q.sub.603), C(O)(Q.sub.601), S(O).sub.2(Q.sub.601), or P(O)(Q.sub.601)(Q.sub.602), [0565] Q.sub.601 to Q.sub.603 are each as described in connection with Q.sub.1, [0566] xe21 may be 1, 2, 3, 4, or 5, and [0567] at least one of Ar.sub.601, L.sub.601, and R.sub.601 may each independently be a electron-deficient nitrogen-containing C.sub.1-C.sub.60 cyclic group that is unsubstituted or substituted with at least one R.sub.10a.

[0568] In one or more embodiments, if (e.g., when) xe11 in Formula 601 is 2 or more, two or more of Ar.sub.601 may be linked together via a single bond.

[0569] In one or more embodiments, Ar.sub.601 in Formula 601 may be an anthracene group unsubstituted or substituted with at least one R.sub.10a.

[0570] In one or more embodiments, the electron transport region may include a compound represented by Formula 601-1:

##STR00184## [0571] wherein, in Formula 601-1, [0572] X.sub.614 may be N or C(R.sub.614), X.sub.615 may be N or C(R.sub.615), X.sub.616 may be N or C(R.sub.616), and at least one of X.sub.614 to X.sub.616 may be N, [0573] L.sub.611 to L.sub.613 are each as described in connection with L.sub.601, [0574] xe611 to xe613 are each as described in connection with xe1, [0575] R.sub.611 to R.sub.613 are each as described in connection with R.sub.601, and [0576] R.sub.614 to R.sub.616 may each independently be hydrogen, deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.20 alkyl group, a C.sub.1-C.sub.20 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group that is unsubstituted or substituted with at least one R.sub.10a, or a C.sub.1-C.sub.60 heterocyclic group that is unsubstituted or substituted with at least one R.sub.10a.

[0577] In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

[0578] The electron transport region may include at least one of (e.g., selected from among) Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq.sub.3, BAlq, TAZ, NTAZ, and/or any combination thereof:

##STR00185## ##STR00186## ##STR00187## ##STR00188## ##STR00189## ##STR00190## ##STR00191## ##STR00192## ##STR00193## ##STR00194## ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200##

[0579] The thickness of the electron transport region may be about 100 to about 5,000 , for example, about 160 to about 4,000 . When the electron transport region includes a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, or any combination thereof, a thickness of the buffer layer, the hole blocking layer, or the electron control layer may each independently be in a range of about 20 to about 1,000 , for example, about 30 to about 300 , and a thickness of the electron transport layer may be in a range of about 100 to about 1,000 , for example, about 150 to about 500 . When the thicknesses of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport region are within the ranges described herein, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.

[0580] The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described herein, a metal-containing material.

[0581] The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of the alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may include at least one selected from among a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, and/or any combination thereof.

[0582] In one or more embodiments, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (Liq) and/or ET-D2:

##STR00201##

[0583] The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150. The electron injection layer may directly contact the second electrode 150.

[0584] The electron injection layer may have: i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including multiple different materials, or iii) a multilayer structure including multiple layers including multiple different materials.

[0585] The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.

[0586] The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof. The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.

[0587] The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may include oxides, halides (for example, fluorides, chlorides, bromides, iodides, and/or the like), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.

[0588] The alkali metal-containing compound may include: an alkali metal oxide, such as Li.sub.2O, Cs.sub.2O, K.sub.2O, and/or the like; alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, KI, and/or the like; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal oxide, such as BaO, SrO, CaO, BaxSr.sub.1-xO (x is a real number satisfying 0<x<1), or BaxCa.sub.1-xO (x is a real number satisfying 0<x<1). The rare earth metal-containing compound may include YbF.sub.3, ScF.sub.3, Sc.sub.2O.sub.3, Y.sub.2O.sub.3, Ce.sub.2O.sub.3, GdF.sub.3, TbF.sub.3, YbI.sub.3, ScI.sub.3, TbI.sub.3, or any combination thereof. In one or more embodiments, the rare earth metal-containing compound may include lanthanide metal telluride. Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La.sub.2Te.sub.3, Ce.sub.2Te.sub.3, Pr.sub.2Te.sub.3, Nd.sub.2Te.sub.3, Pm.sub.2Te.sub.3, Sm.sub.2Te.sub.3, Eu.sub.2Te.sub.3, Gd.sub.2Te.sub.3, Tb.sub.2Te.sub.3, Dy.sub.2Te.sub.3, Ho.sub.2Te.sub.3, Er.sub.2Te.sub.3, Tm.sub.2Te.sub.3, Yb.sub.2Te.sub.3, and Lu.sub.2Te.sub.3.

[0589] The alkali metal complex, the alkaline earth metal complex, and the rare earth metal complex may include i) at least one of (e.g., selected from among) metal ions of the alkali metal, the alkaline earth metal, and the rare earth metal, and ii) as a ligand bonded to the metal ions (e.g., the selected metal ions), for example, a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenyl benzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.

[0590] The electron injection layer may include (e.g., consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described herein. In one or more embodiments, the electron injection layer may further include an organic material (for example, a compound represented by Formula 601).

[0591] In one or more embodiments, the electron injection layer may include (e.g., consist of) i) an alkali metal-containing compound (for example, alkali metal halide), ii) a) an alkali metal-containing compound (for example, alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. In one or more embodiments, the electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, a LiF:Yb co-deposited layer, and/or the like.

[0592] When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal-containing compound, the alkaline earth metal-containing compound, the rare earth metal-containing compound, the alkali metal complex, the alkaline earth-metal complex, the rare earth metal complex, or any combination thereof may be uniformly (e.g., substantially uniformly) or non-uniformly (e.g., substantially non-uniformly) dispersed in a matrix including the organic material.

[0593] The thickness of the electron injection layer may be about 1 to about 100 , and, for example, about 3 to about 90 . When the thickness of the electron injection layer is within the range as described herein, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.

Second Electrode 150

[0594] The second electrode 150 is arranged on the interlayer 130. The second electrode 150 may be a cathode, which is an electron injection electrode, and as a material for forming the second electrode 150, a metal, an alloy, an electrically conductive compound, or any combination thereof, each having a low-work function, may be used.

[0595] The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (AlLi), calcium (Ca), magnesium-indium (MgIn), magnesium-silver (MgAg), ytterbium (Yb), silver-ytterbium (AgYb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a transflective electrode, or a reflective electrode.

[0596] The second electrode 150 may have a single-layer structure or a multilayer structure including a plurality of layers.

Capping Layer

[0597] A first capping layer may be arranged outside (and e.g., on) the first electrode 110, and/or a second capping layer may be arranged outside (and e.g., on) the second electrode 150. In more detail, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are sequentially stacked in the stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in the stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in the stated order.

[0598] Light generated in the emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the first electrode 110 which is a transflective electrode or a transmissive electrode, and the first capping layer. Light generated in the emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the second electrode 150 which is a transflective electrode or a transmissive electrode, and the second capping layer.

[0599] The first capping layer and the second capping layer may increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 is increased, such that the luminescence efficiency of the light-emitting device 10 may be increased.

[0600] Each of the first capping layer and the second capping layer may include a material having a refractive index of 1.6 or more (at 589 nm).

[0601] The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.

[0602] At least one of the first capping layer and/or the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may optionally be substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In one or more embodiments, at least one of the first capping layer and/or the second capping layer may each independently include an amine group-containing compound.

[0603] In one or more embodiments, at least one of the first capping layer and/or the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.

[0604] In one or more embodiments, at least one of the first capping layer and/or the second capping layer may each independently include at least one of (e.g., selected from among) Compounds HT28 to HT33, at least one of (e.g., selected from among) Compounds CP1 to CP6, -NPB, and/or any combination thereof:

##STR00202## ##STR00203##

Film

[0605] The condensed cyclic compound represented by Formula 1 may be included in one or more suitable films. Accordingly, another aspect provides a film including the organometallic compound represented by Formula 1. The film may be, for example, an optical member (or a light control component) (e.g., a color filter, a color conversion member, a capping layer, a light extraction efficiency enhancement layer, a selective light absorbing layer, a polarizing layer, a quantum dot-containing layer, and/or the like), a light blocking member (e.g., a light reflective layer, a light absorbing layer, and/or the like), a protective member (e.g., an insulating layer, a dielectric layer, and/or the like), and/or the like.

Electronic Apparatus

[0606] The light-emitting device may be included in one or more suitable electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and/or the like.

[0607] The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color conversion layer, or iii) a color filter and a color conversion layer. The color filter and/or the color conversion layer may be arranged in at least one traveling direction of light emitted from the light-emitting device. For example, light emitted from the light-emitting device may be blue light, green light, or white light. A detailed description of the light-emitting device is provided herein. In one or more embodiments, the color conversion layer may include quantum dots.

[0608] The electronic apparatus may include a first substrate. The first substrate may include a plurality of subpixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the plurality of subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the plurality of subpixel areas.

[0609] A pixel-defining film may be arranged among the subpixel areas to define each of the subpixel areas.

[0610] The color filter may further include a plurality of color filter areas and light-shielding patterns arranged among the color filter areas, and the color conversion layer may further include a plurality of color conversion areas and light-shielding patterns arranged among the color conversion areas.

[0611] The plurality of color filter areas (or the plurality of color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. In one or more embodiments, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In one or more embodiments, the plurality of color filter areas (or the plurality of color conversion areas) may include quantum dots. In more detail, the first area may include red quantum dots, the second area may include green quantum dots, and the third area may not include (e.g., may exclude) quantum dots. A detailed description of the quantum dots is provided herein. The first area, the second area, and/or the third area may each further include a scatterer.

[0612] In one or more embodiments, the light-emitting device may be to emit first light, the first area may be to absorb the first light to emit 1-1 color light, the second area may be to absorb the first light to emit 2-1 color light, and the third area may be to absorb the first light to emit 3-1 color light. In this case, the 1-1 color light, the 2-1 color light, and the 3-1 color light may have different maximum emission wavelengths. In more detail, the first light may be blue light, the 1-1 color light may be red light, the 2-1 color light may be green light, and the 3-1 color light may be blue light.

[0613] The electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device as described herein. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the light-emitting device.

[0614] The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.

[0615] The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like.

[0616] The electronic apparatus may further include a encapsulation portion for encapsulation of the light-emitting device. The encapsulation portion may be arranged between the color filter and/or the color conversion layer and the light-emitting device. The encapsulation portion allows light from the light-emitting device to be extracted to the outside, and concurrently (e.g., simultaneously) prevents ambient air and moisture from penetrating into the light-emitting device. The encapsulation portion may be an encapsulation substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including at least one layer of an organic layer and/or an inorganic layer. When the encapsulation portion is a thin film encapsulation layer, the electronic apparatus may be flexible.

[0617] One or more suitable functional layers may be additionally arranged on the encapsulation portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of the functional layers may include a touch screen layer and a polarizing layer. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, and/or the like).

[0618] The authentication apparatus may further include, in addition to the light-emitting device as described herein, a biometric information collector.

[0619] The electronic apparatus (for example, a light-emitting apparatus) may be applied to one or more suitable electronic equipments. In one or more embodiments, the electronic apparatus may be applied to one or more suitable displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, one or more suitable measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and/or the like.

Electronic Equipment

[0620] The electronic apparatus may be applied to one or more suitable electronic equipments. Thus, the light-emitting device may be included in one or more suitable electronic equipment.

[0621] In one or more embodiments, the light-emitting apparatus may be applied to one or more suitable electronic equipments. The electronic equipment may include the light-emitting apparatus, and may further include module or apparatus with additional functions in addition to the light-emitting apparatus.

[0622] In one or more embodiments, the electronic equipment including the light-emitting device may be at least one (e.g., selected from among) of a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, a light for indoor or outdoor lighting and/or signaling, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a mobile phone, a tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro display, a 3D display, a virtual or augmented-reality display, a vehicle, a video wall including multiple displays tiled together, a theater or stadium screen, a phototherapy device, a signboard, and combinations thereof.

[0623] Because the light-emitting device has excellent or suitable effects in terms of luminescence efficiency and long lifespan, the electronic equipment including the light-emitting device may have characteristics with high luminance, high resolution, and low power consumption.

Description of FIGS. 2 and 3

[0624] FIG. 2 is a cross-sectional view showing a light-emitting apparatus as an example of the electronic apparatus according to one or more embodiments.

[0625] The light-emitting apparatus of FIG. 2 includes a substrate 100, a thin-film transistor (TFT), a light-emitting device, and an encapsulation portion 300 that seals the light-emitting device.

[0626] The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be arranged on the substrate 100. The buffer layer 210 may prevent or reduce penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.

[0627] A TFT may be arranged on the buffer layer 210. The TFT may include an activation layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.

[0628] The activation layer 220 may include an inorganic semiconductor, such as silicon or polysilicon, an organic semiconductor, or an oxide semiconductor, and may include a source region, a drain region, and a channel region.

[0629] A gate insulating film 230 for insulating the activation layer 220 from the gate electrode 240 may be arranged on the activation layer 220, and the gate electrode 240 may be arranged on the gate insulating film 230.

[0630] An interlayer insulating film 250 may be arranged on the gate electrode 240. The interlayer insulating film 250 may be arranged between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270, to insulate from one another.

[0631] The source electrode 260 and the drain electrode 270 may be arranged on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source region and the drain region of the activation layer 220, and the source electrode 260 and the drain electrode 270 may be arranged in contact with the exposed portions of the source region and the drain region of the activation layer 220.

[0632] The TFT may be electrically connected to a light-emitting device to drive the light-emitting device, and may be covered and protected by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device may be provided on the passivation layer 280. The light-emitting device may include the first electrode 110, the interlayer 130, and the second electrode 150.

[0633] The first electrode 110 may be arranged on the passivation layer 280. The passivation layer 280 may be arranged to expose a portion of the drain electrode 270, not fully covering the drain electrode 270, and the first electrode 110 may be arranged to be connected to the exposed portion of the drain electrode 270.

[0634] A pixel-defining film 290 including an insulating material may be arranged on the first electrode 110. The pixel-defining film 290 may expose a certain region of the first electrode 110, and the interlayer 130 may be formed in the exposed region of the first electrode 110. The pixel-defining film 290 may be a polyimide-based organic film or a polyacrylic-based organic film. In one or more embodiments, at least some layers of the interlayer 130 may extend beyond the upper portion of the pixel-defining film 290 to be arranged in the form of a common layer.

[0635] The second electrode 150 may be arranged on the interlayer 130, and a second capping layer 170 may be additionally formed on the second electrode 150. The second capping layer 170 may be formed to cover the second electrode 150.

[0636] The encapsulation portion 300 may be arranged on the second capping layer 170. The encapsulation portion 300 may be arranged on a light-emitting device to protect the light-emitting device from moisture or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, and/or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), and/or the like), or any combination thereof; and/or a (e.g., any suitable) combination of the inorganic film and the organic film.

[0637] FIG. 3 is a cross-sectional view of a light-emitting apparatus as an example of the electronic apparatus according to one or more embodiments.

[0638] The light-emitting apparatus of FIG. 3 is substantially the same as the light-emitting apparatus of FIG. 2, except that a light-shielding pattern 500 and a functional region 400 are additionally arranged on the encapsulation portion 300. The functional region 400 may be i) a color filter area, ii) a color conversion area, or iii) a combination of the color filter area and the color conversion area. In one or more embodiments, a light-emitting device included in the light-emitting apparatus of FIG. 3 may be a tandem light-emitting device.

Description of FIG. 4

[0639] FIG. 4 is a block diagram of an electronic equipment 1 according to one or more embodiments. Referring to FIG. 4, the electronic equipment 1 according to one or more embodiments may include a light-emitting module 11, a processor 12, a memory 13, and a power module 14.

[0640] The processor 12 may include at least one of a central processing unit (CPU), an application processor (AP), a graphics processing unit (GPU), a communication processor (CP), an image signal processor (ISP), or a controller.

[0641] The memory 13 may store data information necessary for the operation of the processor 12 or the light-emitting module 11. When the processor 12 executes an application stored in the memory 13, video data signals and/or input control signals are transmitted to the light-emitting module 11, which processes the received signals to output video information through a display screen.

[0642] The power module 14 may include a power supply module, such as a power adapter or a battery, and a power conversion module that converts power supplied by the power supply module to generate power required for the operation of the electronic equipment 1.

[0643] At least one of the components of the above-described electronic equipment 1 may be included in the light-emitting apparatus according to the aforementioned embodiments. Furthermore, some of the individual module's functionally (e.g., included in a single module) may be incorporated into the light-emitting apparatus, while other functionalities may be provided separately from the light-emitting apparatus. For example, the light-emitting apparatus may include the light-emitting module 11, and the processor 12, memory 13, and power module 14 may be provided as other apparatuses within the electronic quipment 1 rather than being part of the light-emitting apparatus.

Description of FIG. 5

[0644] FIG. 5 is a schematic diagram of electronic equipment according to one or more embodiments.

[0645] Referring to FIG. 5, electronic equipment to which an electronic apparatus (for example, a light-emitting apparatus) is applied may include, not only image display electronic equipment, such as a smartphone 1_1a, a tablet PC 1_1b, a laptop 1_1c, a TV 1_1d, and a desktop monitor 1_1e, but also wearable electronic equipment including light-emitting modules such as smart glasses 1_2a, a head-mounted displays 1_2b, and a smartwatch 1_2c, as well as vehicle electronic equipments 1_3 including light-emitting modules such as an instrument panel, a center fascia, a center information display (CID) placed on the dashboard, and a room mirror display.

Description of FIG. 6

[0646] FIG. 6 is a schematic perspective view of electronic equipment 1 including a light-emitting device according to one or more embodiments. The electronic equipment 1 may be, as an apparatus that displays a moving image or a still image, portable electronic equipment, such as a mobile phone, a smartphone, a tablet personal computer (PC), a mobile communication terminal, an electronic notebook, an electronic book, a portable multimedia player (PMP), a navigation, or an ultra-mobile PC (UMPC), as well as one or more suitable products, such as a television, a laptop, a monitor, a billboard, or an Internet of things (IoT) device. The electronic equipment 1 may be such a product described herein or a part thereof. In some embodiments, the electronic equipment 1 may be a wearable device, such as a smart watch, a watch phone, a glasses-type or kind display, or a head mounted display (HMD), or a part of the wearable device. However, embodiments are not limited thereto. In one or more embodiments, the electronic equipment 1 may be a dashboard of a vehicle, a center information display (CID) arranged on a center fascia or dashboard of a vehicle, a room mirror display instead of a side-view mirror of a vehicle, an entertainment for the back seat of a vehicle, or a display arranged on the back of the front seat of a vehicle, a head up display (HUD) installed on the front of a vehicle or projected on a front window glass, or a computer generated hologram augmented reality head up display (CGH AR HUD). FIG. 6 illustrates one or more embodiments in which the electronic equipment 1 is a smartphone for convenience of explanation.

[0647] The electronic equipment 1 may include a display area DA and a non-display area NDA outside the display area DA. A display apparatus may implement an image through an array of a plurality of pixels that are two-dimensionally arranged in the display area DA.

[0648] The non-display area NDA is an area that does not display an image, and may entirely be around (e.g., surround) the display area DA. On the non-display area NDA, a driver for providing electrical signals or power to display devices arranged on the display area DA may be arranged. On the non-display area NDA, a pad, which is an area to which an electronic element or a printed circuit board, may be electrically connected may be arranged.

[0649] In the electronic equipment 1, the length in an x-axis direction and the length in a y-axis direction may be different from each other. In one or more embodiments, as shown in FIG. 6, the length in the x-axis direction may be less than the length in the y-axis direction. In one or more embodiments, the length in the x-axis direction may be substantially the same as the length in the y-axis direction. In one or more embodiments, the length in the x-axis direction may be greater than the length in the y-axis direction.

Descriptions of FIGS. 7 and 8A to 8C

[0650] FIG. 7 is a schematic view of the exterior of a vehicle 1000 as electronic equipment including a light-emitting device, according to one or more embodiments. FIGS. 8A to 8C are each a schematic view of the interior of the vehicle 1000 according to one or more embodiments.

[0651] Referring to FIGS. 7, 8A, 8B, and 8C, the vehicle 1000 may refer to one or more suitable apparatuses for moving a subject to be transported, such as a human, an aspect, or an animal, from a departure point to a destination point. The vehicle 1000 may include a vehicle traveling on a road or track, a vessel moving over the sea or river, an airplane flying in the sky using the action of air, and/or the like.

[0652] The vehicle 1000 may travel on a road or a track. The vehicle 1000 may move in a certain direction according to rotation of at least one wheel. In one or more embodiments, the vehicle 1000 may include a three-wheeled or four-wheeled vehicle, a construction machine, a two-wheeled vehicle, a prime mover device, a bicycle, and a train running on a track.

[0653] The vehicle 1000 may include a body of the 1000 having an interior and an exterior, and a chassis in which mechanical apparatuses necessary for driving are installed as other parts except for the body of the vehicle 1000. The exterior of the body of the vehicle may include a front panel, a bonnet, a roof panel, a rear panel, a trunk, a pillar provided at a boundary between doors, and/or the like. The chassis of the vehicle 1000 may include a power generating device, a power transmitting device, a driving device, a steering device, a braking device, a suspension device, a transmission device, a fuel device, front and rear wheels, left and right wheels, and/or the like.

[0654] The vehicle 1000 may include a side window glass 1100, a front window glass 1200, a side-view mirror 1300, a cluster 1400, a center fascia 1500, a passenger seat dashboard 1600, and a display apparatus 2.

[0655] The side window glass 1100 and the front window glass 1200 may be partitioned by a pillar arranged between the side window glass 1100 and the front window glass 1200.

[0656] The side window glass 1100 may be installed on the side of the vehicle 1000. In one or more embodiments, the side window glass 1100 may be installed on a door of the vehicle 1000. A plurality of side window glasses 1100 may be provided and may face each other. In one or more embodiments, the side window glass 1100 may include a first side window glass 1110 and a second side window glass 1120. In one or more embodiments, the first side window glass 1110 may be arranged adjacent to the cluster 1400. The second side window glass 1120 may be arranged adjacent to the passenger seat dashboard 1600.

[0657] In one or more embodiments, the side window glasses 1100 may be spaced and/or apart (e.g., spaced apart or separated) from each other in an x direction or a x direction. In one or more embodiments, the first side window glass 1110 and the second side window glass 1120 may be spaced and/or apart (e.g., spaced apart or separated) from each other in the x direction or the x direction. For example, an imaginary straight line L connecting the side window glasses 1100 may extend in the x direction or the x direction. In one or more embodiments, an imaginary straight line L connecting the first side window glass 1110 and the second side window glass 1120 to each other may extend in the x direction or the x direction.

[0658] The front window glass 1200 may be installed in front of the vehicle 1000. The front window glass 1200 may be arranged between the side window glasses 1100 opposite to (e.g., facing) each other.

[0659] The side-view mirror 1300 may provide a rear view of the vehicle 1000. The side-view mirror 1300 may be installed on the exterior of the body of the vehicle. In one or more embodiments, a plurality of side-view mirrors 1300 may be provided. Any one of the plurality of side-view mirrors 1300 may be arranged outside the first side window glass 1110. The other one of the plurality of side-view mirrors 1300 may be arranged outside the second side window glass 1120.

[0660] The cluster 1400 may be arranged in front of a steering wheel. The cluster 1400 may include a tachometer, a speedometer, a coolant thermometer, a fuel gauge, a turn signal indicator, a high beam indicator, a warning light, a seat belt warning light, an odometer, a tachograph, an automatic shift selector indicator, a door open warning light, an engine oil warning light, and/or a low fuel warning light.

[0661] The center fascia 1500 may include a control panel on which a plurality of buttons for adjusting an audio device, an air conditioning device, and a seat heater are arranged. The center fascia 1500 may be arranged on one side of the cluster 1400.

[0662] The passenger seat dashboard 1600 may be spaced and/or apart (e.g., spaced apart or separated) from the cluster 1400, and the center fascia 1500 may be arranged between the cluster 1400 and the passenger seat dashboard 1600. In one or more embodiments, the cluster 1400 may be arranged to correspond to a driver seat, and the passenger seat dashboard 1600 may be arranged to correspond to a passenger seat. In one or more embodiments, the cluster 1400 may be adjacent to the first side window glass 1110, and the passenger seat dashboard 1600 may be adjacent to the second side window glass 1120.

[0663] In one or more embodiments, the display apparatus 2 may include a display panel 3, and the display panel 3 may display an image. The display apparatus 2 may be arranged inside the vehicle 1000. In one or more embodiments, the display apparatus 2 may be arranged between the side window glasses 1100 opposite to (e.g., facing) each other. The display apparatus 2 may be arranged on at least one of the cluster 1400, the center fascia 1500, and the passenger seat dashboard 1600.

[0664] The display apparatus 2 may include an organic light-emitting display, an inorganic electroluminescent display, a quantum dot display, and/or the like. Hereinafter, as the display apparatus 2 according to one or more embodiments, an organic light-emitting display apparatus including the light-emitting device will be described as an example, but one or more suitable types (kinds) of display apparatuses as described herein may be used in embodiments.

[0665] Referring to FIG. 8A, the display apparatus 2 may be arranged on the center fascia 1500. In one or more embodiments, the display apparatus 2 may display navigation information. In one or more embodiments, the display apparatus 2 may display information regarding audio settings, video setting, or vehicle settings.

[0666] Referring to FIG. 8B, the display apparatus 2 may be arranged on the cluster 1400. In this case, the cluster 1400 may display driving information and/or the like through the display apparatus 2. For example, the cluster 1400 may be implemented digitally. The digital cluster 1400 may display vehicle information and driving information. In one or more embodiments, a needle and a gauge of a tachometer and one or more suitable warning light icons may be displayed by a digital signal.

[0667] Referring to FIG. 8C, the display apparatus 2 may be arranged on the passenger seat dashboard 1600. The display apparatus 2 may be embedded in the passenger seat dashboard 1600 or arranged on the passenger seat dashboard 1600. In one or more embodiments, the display apparatus 2 arranged on the passenger seat dashboard 1600 may display an image related to information displayed on the cluster 1400 and/or information displayed on the center fascia 1500. In one or more embodiments, the display apparatus 2 arranged on the passenger seat dashboard 1600 may display information different from information displayed on the cluster 1400 and/or information displayed on the center fascia 1500.

Manufacturing Method

[0668] Layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region may be formed in a certain region by using one or more suitable methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, laser-induced thermal imaging, and/or the like.

[0669] When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature in a range of about 100 C. to about 500 C., at a vacuum degree in a range of about 10.sup.8 torr to about 10-3 torr, and at a deposition speed in a range of about 0.01 angstrom per second (/sec) to about 100 /sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.

DEFINITION OF TERMS

[0670] The term C.sub.3-C.sub.60 carbocyclic group as used herein refers to a cyclic group consisting of carbon atoms as the only ring-forming atoms and having three to sixty carbon atoms, and the term C.sub.1-C.sub.60 heterocyclic group as used herein refers to a cyclic group that has one to sixty carbon atoms and further includes, in addition to a carbon atom, a heteroatom as a ring-forming atom. The C.sub.3-C.sub.60 carbocyclic group and the C.sub.1-C.sub.60 heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. In one or more embodiments, the number of ring-forming atoms of the C.sub.1-C.sub.60 heterocyclic group may be 3 to 61.

[0671] The cyclic group as used herein may include both (e.g., simultaneously) the C.sub.3-C.sub.60 carbocyclic group and the C.sub.1-C.sub.60 heterocyclic group.

[0672] The term electron-rich C.sub.3-C.sub.60 cyclic group as used herein refers to a cyclic group that has 3 to 60 carbon atoms and does not include *N* as a ring-forming moiety, and the term electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group as used herein refers to a heterocyclic group that has 1 to 60 carbon atoms and includes *N* as a ring-forming moiety.

[0673] In one or more embodiments, the C.sub.3-C.sub.60 carbocyclic group may be i) Group T1 or ii) a condensed cyclic group in which two or more of Group T1 are condensed with each other (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group), [0674] the C.sub.1-C.sub.60 heterocyclic group may be i) Group T2, ii) a condensed cyclic group in which two or more of Group T2 are condensed with each other, or iii) a condensed cyclic group in which at least one Group T2 and at least one Group T1 are condensed with each other (e.g., a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, and/or the like), [0675] the electron-rich C.sub.3-C.sub.60 cyclic group may be i) Group T1, ii) a condensed cyclic group in which two or more of Group T1 are condensed with each other, iii) Group T3, iv) a condensed cyclic group in which two or more of Group T3 are condensed with each other, or v) a condensed cyclic group in which at least one Group T3 and at least one Group T1 are condensed with each other (for example, the C.sub.3-C.sub.60 carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonaphthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, and/or the like), [0676] the electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group may be i) Group T4, ii) a condensed cyclic group in which two or more of Group T4 are condensed with each other, iii) a condensed cyclic group in which at least one Group T4 and at least one Group T1 are condensed with each other, iv) a condensed cyclic group in which at least one Group T4 and at least one Group T3 are condensed with each other, or v) a condensed cyclic group in which at least one Group T4, at least one Group T1, and at least one Group T3 are condensed with one another (e.g., a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, and/or the like), [0677] Group T1 may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group, [0678] Group T2 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group, [0679] Group T3 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and [0680] Group T4 may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.

[0681] The terms the cyclic group, the C.sub.3-C.sub.60 carbocyclic group, the C.sub.1-C.sub.60 heterocyclic group, the electron-rich C.sub.3-C.sub.60 cyclic group, and the electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group as used herein may each refer to a group condensed to any cyclic group, a monovalent group, or a polyvalent group (e.g., a divalent group, a trivalent group, a tetravalent group, and/or the like) according to the structure of a formula for which the corresponding term is used. In one or more embodiments, the benzene group may be a benzo group, a phenyl group, a phenylene group, and/or the like, which may be easily understood by those of ordinary skill in the art according to the structure of a formula including the benzene group.

[0682] Depending on context, a divalent group may refer or be a polyvalent (e.g., trivalent, tetravalent, etc., and not just divalent) group per, e.g., the structure of a formula in connection with which of the terms are utilized.

[0683] Examples of the monovalent C.sub.3-C.sub.60 carbocyclic group and the monovalent C.sub.1-C.sub.60 heterocyclic group may include a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.1-C.sub.10 heterocycloalkyl group, a C.sub.3-C.sub.10 cycloalkenyl group, a C.sub.1-C.sub.10 heterocycloalkenyl group, a C.sub.6-C.sub.60 aryl group, a C.sub.1-C.sub.60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of the divalent C.sub.3-C.sub.60 carbocyclic group and the divalent C.sub.1-C.sub.60 heterocyclic group are a C.sub.3-C.sub.10 cycloalkylene group, a C.sub.1-C.sub.10 heterocycloalkylene group, a C.sub.3-C.sub.10 cycloalkenylene group, a C.sub.1-C.sub.10 heterocycloalkenylene group, a C.sub.6-C.sub.60 arylene group, a C.sub.1-C.sub.60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.

[0684] The term C.sub.1-C.sub.60 alkyl group as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term C.sub.1-C.sub.60 alkylene group as used herein refers to a divalent group having the same structure as the C.sub.1-C.sub.60 alkyl group.

[0685] The term C.sub.2-C.sub.60 alkenyl group as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C.sub.2-C.sub.60 alkyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term C.sub.2-C.sub.60 alkenylene group as used herein refers to a divalent group having the same structure as the C.sub.2-C.sub.60 alkenyl group.

[0686] The term C.sub.2-C.sub.60 alkynyl group as used herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C.sub.2-C.sub.60 alkyl group, and examples thereof include an ethynyl group and a propynyl group. The term C.sub.2-C.sub.60 alkynylene group as used herein refers to a divalent group having the same structure as the C.sub.2-C.sub.60 alkynyl group.

[0687] The term C.sub.1-C.sub.60 alkoxy group as used herein refers to a monovalent group represented by OA.sub.101 (wherein A.sub.101 is the C.sub.1-C.sub.60 alkyl group), and examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

[0688] The term C.sub.3-C.sub.10 cycloalkyl group as used herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, and/or the like. The term C.sub.3-C.sub.10 cycloalkylene group as used herein refers to a divalent group having the same structure as the C.sub.3-C.sub.10 cycloalkyl group.

[0689] The term C.sub.1-C.sub.10 heterocycloalkyl group as used herein refers to a monovalent cyclic group that has one to ten carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom, and examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term C.sub.1-Cia heterocycloalkylene group as used herein refers to a divalent group having the same structure as the C.sub.1-Cia heterocycloalkyl group.

[0690] The term C.sub.3-C.sub.10 cycloalkenyl group as used herein refers to a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term C.sub.3-C.sub.10 cycloalkenylene group as used herein refers to a divalent group having the same structure as the C.sub.3-C.sub.10 cycloalkenyl group.

[0691] The term C.sub.1-C.sub.10 heterocycloalkenyl group as used herein refers to a monovalent cyclic group that has one to ten carbon atoms, further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom, and has at least one double bond in the ring thereof. Examples of the C.sub.1-C.sub.10 heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term C.sub.1-Cia heterocycloalkenylene group as used herein refers to a divalent group having the same structure as the C.sub.1-C.sub.10 heterocycloalkenyl group.

[0692] The term C.sub.6-C.sub.60 aryl group as used herein refers to a monovalent group having a carbocyclic aromatic system of six to sixty carbon atoms, and the term C.sub.6-C.sub.60 arylene group as used herein refers to a divalent group having a carbocyclic aromatic system of six to sixty carbon atoms. Examples of the C.sub.6-C.sub.60 aryl group include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. When the C.sub.6-C.sub.60 aryl group and the C.sub.6-C.sub.60 arylene group each include two or more rings, the two or more rings may be condensed with each other.

[0693] The term C.sub.1-C.sub.60 heteroaryl group as used herein refers to a monovalent group having a heterocyclic aromatic system that has one to sixty carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom. The term C.sub.1-C.sub.60 heteroarylene group as used herein refers to a divalent group having a heterocyclic aromatic system that has one to sixty carbon atoms and further includes, in addition to the carbon atoms, at least one heteroatom as a ring-forming atom. Examples of the C.sub.1-C.sub.60 heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C.sub.1-C.sub.60 heteroaryl group and the C.sub.1-C.sub.60 heteroarylene group each include two or more rings, the two or more rings may be condensed with each other.

[0694] The term monovalent non-aromatic condensed polycyclic group as used herein refers to a monovalent group having two or more rings condensed with each other, only carbon atoms (for example, eight to sixty carbon atoms) as ring-forming atoms, and no aromaticity in its molecular structure if (e.g., when) considered as a whole. Examples of the monovalent non-aromatic condensed polycyclic group include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indeno anthracenyl group. The term divalent non-aromatic condensed polycyclic group as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

[0695] The term monovalent non-aromatic condensed heteropolycyclic group as used herein refers to a monovalent group that has two or more rings condensed with each other, further includes, in addition to carbon atoms (for example, one to sixty carbon atoms), at least one heteroatom as a ring-forming atom, and has no aromaticity in its molecular structure if (e.g., when) considered as a whole. Examples of the monovalent non-aromatic condensed heteropolycyclic group include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indeno carbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphthosilolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term divalent non-aromatic condensed heteropolycyclic group as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

[0696] The term C.sub.6-C.sub.60 aryloxy group as used herein indicates OA.sub.102 (wherein A.sub.102 is the C.sub.6-C.sub.60 aryl group), and the term C.sub.6-C.sub.60 arylthio group as used herein indicates SA.sub.103 (wherein A.sub.103 is the C.sub.6-C.sub.60 aryl group).

[0697] The term C.sub.7-C.sub.60 arylalkyl group as used herein refers to -A.sub.104A.sub.10s (wherein A.sub.104 is a C.sub.1-C.sub.54 alkylene group, and A.sub.105 is a C.sub.6-C.sub.59 aryl group), and the term C.sub.2-C.sub.60 heteroarylalkyl group as used herein refers to -A.sub.106A.sub.107 (wherein A.sub.106 is a C.sub.1-C.sub.59 alkylene group, and A.sub.107 is a C.sub.1-C.sub.59 heteroaryl group).

[0698] The term R.sub.10a as used herein may be: [0699] deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; [0700] a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, or a C.sub.1-C.sub.60 alkoxy group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.11)(Q.sub.12)(Q.sub.13), N(Q.sub.11)(Q.sub.12), B(Q.sub.11)(Q.sub.12), C(O)(Q.sub.11), S(O).sub.2(Q.sub.11), P(O)(Q.sub.11)(Q.sub.12), or any combination thereof; [0701] a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, or a C.sub.2-C.sub.60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, a nitro group, a C.sub.1-C.sub.60 alkyl group, a C.sub.2-C.sub.60 alkenyl group, a C.sub.2-C.sub.60 alkynyl group, a C.sub.1-C.sub.60 alkoxy group, a C.sub.3-C.sub.60 carbocyclic group, a C.sub.1-C.sub.60 heterocyclic group, a C.sub.6-C.sub.60 aryloxy group, a C.sub.6-C.sub.60 arylthio group, a C.sub.7-C.sub.60 arylalkyl group, a C.sub.2-C.sub.60 heteroarylalkyl group, Si(Q.sub.21)(Q.sub.22)(Q.sub.23), N(Q.sub.21)(Q.sub.22), B(Q.sub.21)(Q.sub.22), C(O)(Q.sub.21), S(O).sub.2(Q.sub.21), P(O)(Q.sub.21)(Q.sub.22), or any combination thereof; or [0702] Si(Q.sub.31)(Q.sub.32)(Q.sub.33), N(Q.sub.31)(Q.sub.32), B(Q.sub.31)(Q.sub.32), C(O)(Q.sub.31), S(O).sub.2(Q.sub.31), or P(O)(Q.sub.31)(Q.sub.32).

[0703] Q.sub.1 to Q.sub.3, Q.sub.11 to Q.sub.13, Q.sub.21 to Q.sub.23, and Q.sub.31 to Q.sub.33 as used herein may each independently be: hydrogen; deuterium; F; CI; Br; I; a hydroxyl group; a cyano group; a nitro group; a C.sub.1-C.sub.60 alkyl group; a C.sub.2-C.sub.60 alkenyl group; a C.sub.2-C.sub.60 alkynyl group; a C.sub.1-C.sub.60 alkoxy group; a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.60 heterocyclic group, each unsubstituted or substituted with deuterium, F, a cyano group, a C.sub.1-C.sub.60 alkyl group, a C.sub.1-C.sub.60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C.sub.7-C.sub.60 arylalkyl group; or a C.sub.2-C.sub.60 heteroarylalkyl group.

[0704] The term heteroatom as used herein refers to any atom other than a carbon atom and hydrogen atom. Examples of the heteroatom include O, S, N, P, Si, B, Ge, Se, or any combination thereof.

[0705] The term transition metal used herein includes hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and/or the like.

[0706] The term Ph as used herein refers to a phenyl group, the term Me as used herein refers to a methyl group, the term Et as used herein refers to an ethyl group, the term tert-Bu or Bu.sup.t as used herein refers to a tert-butyl group, and the term OMe as used herein refers to a methoxy group.

[0707] The term biphenyl group as used herein refers to a phenyl group that is substituted with a phenyl group. For example, the biphenyl group may be a substituted phenyl group having a C.sub.6-C.sub.60 aryl group as a substituent.

[0708] The term terphenyl group as used herein refers to a phenyl group substituted with a biphenyl group. The terphenyl group is a substituted phenyl group having, as a substituent, a C.sub.6-C.sub.60 aryl group substituted with a C.sub.6-C.sub.60 aryl group. [0709] * and * as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.

[0710] The terms x-axis, y-axis, and z-axis as used herein are not limited to three axes in an orthogonal coordinate system, and may be interpreted in a broader sense than the aforementioned three axes in an orthogonal coordinate system. For example, the x-axis, y-axis, and z-axis may describe axes that are orthogonal to each other, or may describe axes that are in different directions that are not orthogonal to each other.

[0711] Terms such as substantially, about, and approximately are used as relative terms and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. They may be inclusive of the stated value and an acceptable range of deviation as determined by one of ordinary skill in the art, considering the limitations and error associated with measurement of that quantity. For example, about may refer to one or more standard deviations, or 30%, 20%, 10%, 5% of the stated value.

[0712] Numerical ranges disclosed herein include and are intended to disclose all subsumed sub-ranges of the same numerical precision. For example, a range of 1.0 to 10.0 includes all subranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Applicant therefore reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

[0713] The light-emitting device, the electronic apparatus, a device of manufacturing thereof, and/or any other relevant devices or components according to embodiments of the present disclosure described herein may be implemented utilizing any suitable hardware, firmware (e.g., an application-specific integrated circuit), software, or a combination of software, firmware, and hardware. For example, the one or more suitable components of the light-emitting device and/or the electronic apparatus, may be formed on one integrated circuit (IC) chip or on separate IC chips. Further, the one or more suitable components of the light-emitting device and/or the electronic apparatus may be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on one substrate. Further, the one or more suitable components of the device and/or apparatus may be a process or thread, running on one or more processors, in one or more computing devices, executing computer program instructions and interacting with other system components for performing the one or more suitable functionalities described herein. The computer program instructions are stored in a memory which may be implemented in a computing device using a standard memory device, such as, for example, a random access memory (RAM). The computer program instructions may also be stored in other non-transitory computer readable media such as, for example, a CD-ROM, flash drive, or the like. Also, a person of skill in the art should recognize that the functionality of one or more suitable computing devices may be combined or integrated into a single computing device, or the functionality of a particular computing device may be distributed across one or more other computing devices without departing from the scope of the embodiments of the present disclosure.

[0714] Hereinafter, compounds according to one or more embodiments and light-emitting devices according to one or more embodiments will be described in more detail with reference to the following synthesis examples and examples. The wording B was used instead of A used in describing Synthesis Examples refers to that an substantially identical molar equivalent of B was used in place of A.

EXAMPLES

Synthesis Example 1: Synthesis of Compound 1

##STR00204##

1) Synthesis of Intermediate 1-1

[0715] After 5-bromo-2-methylaniline and 3-((4-(tert-butyl)pyridin-2-yl)methyl)-6-phenyl-[1,1:2,1-terphenyl]-2-amine were dissolved in a Schlenk tube, formaldehyde was added thereto, and the mixture was stirred at room temperature for 24 hours to obtain a reaction product. Afterwards, an extraction process was performed thereon three times by using methylene chloride (MC) and water to obtain an organic layer. (The extraction process may be carried out as follows: the reaction product was diluted with water and the resultant solution was transferred to a separatory funnel. A first portion of MC was added to the resultant solution which was thoroughly mixed and then allowed to settle, forming two distinct layers: an aqueous layer and an organic layer (MC). The bottom layer was carefully separated and removed from the separatory funnel. Second and third MC portions were added to the separatory funnel and each addition was followed, in turn, by a thorough mixing, settling, separation and removal from the separatory funnel. The three MC portions were then combined into a single organic layer.) The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Intermediate 1-1 (yield: 45%).

2) Synthesis of Intermediate 1-2

[0716] After Intermediate 1-1 was dissolved in MC, bis(pinacolato)diboron was slowly added thereto. The mixture was stirred at 80 C. for 24 hours, and an extraction process was performed thereon three times by using ethyl acetate and water to obtain an organic layer. The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Intermediate 1-2 (yield: 83%).

3) Synthesis of Intermediate 1-3

[0717] Intermediate 1-2 and 9-bromo-9-(5-chloro-2,6-diisopropyl-[1,1-biphenyl]-3-yl)-9H-fluorene were dissolved in dimethyl sulfoxide(DMSO) and then stirred at 100 C. for 3 hours to obtain a reaction product. The reaction product was cooled to room temperature, and an extraction process was performed thereon three times by using ethyl acetate and water to obtain an organic layer. The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Intermediate 1-3 (yield: 85%).

4) Synthesis of Intermediate 1-4

[0718] Intermediate 1-3 and N.sup.1-(2,6-diisobutylphenyl)benzene-1 ,2-diamine were dissolved in toluene (0.1 M), and then stirred at 110 C. for 3 hours to obtain a reaction product. After cooling the reaction product to room temperature, the solvent was removed therefrom by distillation under reduced pressure at 8 mbar, and an extraction process was performed thereon three times by using MC and water to obtain an organic layer. The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Intermediate 1-4 (yield: 61%).

5) Synthesis of Intermediate 1-5

[0719] After Intermediate 1-4 was dissolved in triethyl orthoformate, 37% HCL was added thereto, and then stirred at 80 C. to obtain a reaction product. The reaction product was cooled at room temperature, and triethyl orthoformate in the reaction product was concentrated. Then, an extraction process was performed thereon three times by using MC and water to obtain an organic layer. The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Intermediate 1-5 (yield: 60%).

6) Synthesis of Compound 1

[0720] Intermediate 1-5, potassium platinum(II)chloride (K.sub.2PtCl.sub.4), and 2,6-lutidine were dissolved in 1,2-dichlorobenzene (0.05 M) and then stirred at 120 C. in a nitrogen atmosphere for 3 hours to obtain a reaction product. The reaction product was cooled at room temperature, and 1,2-dichlorobenzene in the reaction product was concentrated. Then, an extraction process was performed thereon three times by using dichloromethane and water to obtain an organic layer. The organic layer thus obtained was dried by using magnesium sulfate, and concentrated to synthesize Compound 1 (yield: 53%).

Synthesis Example 2: Synthesis of Compound 2

##STR00205##

[0721] Compound 2 was synthesized (yield: 52%) in substantially the same manner as in Synthesis Example 1, except that when synthesizing Intermediate 2-3, bromo(5-chloro-2,6-diisopropyl-[1,1-biphenyl]-3-yl)diphenylsilane was used instead of 9-bromo-9-(5-chloro-2,6-diisopropyl-[I,I-biphenyl]-3-yl)-9H-fluorene.

Synthesis Example 3: Synthesis of Compound 3

##STR00206##

[0722] Compound 3 was synthesized (yield: 58%) in substantially the same manner as in Synthesis Example 1, except that when synthesizing Intermediate 3-1, 2-(tert-butyl)-6-((4-(tert-butyl)pyridin-2-yl)methyl)aniline was used instead of 3-((4-(tert-butyl)pyridin-2-yl)methyl)-6-phenyl-[1,1:2,1-terphenyl]-2-amine.

Synthesis Example 4: Synthesis of Compound 10

##STR00207##

[0723] Compound 10 was synthesized (yield: 62%) in substantially the same manner as in Synthesis Example 1, except that 3-amino-4-methylphenyl hypobromite was used instead of 5-bromo-2-methylaniline, and 2-((4-(tert-butyl)pyridin-2-yl)methyl)aniline was used instead of 3-((4-(tert-butyl)pyridin-2-yl)methyl)-6-phenyl-[1,1:2,1-terphenyl]-2amine when synthesizing Intermediate 10-1, 1-bromo-3-chlorobenzene was used instead of 9-bromo-9-(5-chloro-2,6-diisopropyl-[1,1-biphenyl]-3-yl)-9H-fluorene when synthesizing Intermediate 10-3, and N.sup.1-([1,1:3,1 terphenyl]-2-yl)benzene-1,2-diamine was used instead of N.sup.1-(2,6-diisobutylphenyl)benzene-1,2-diamine when synthesizing Intermediate 10-4.

Evaluation Example 1

[0724] The highest occupied molecular orbital (HOMO) energy level (E.sub.HOMO), lowest unoccupied molecular orbital (LUMO) energy level (E.sub.LUMO), T.sub.1 energy level (nanometer (nm)), and presence ratio (%) of triplet metal-to-ligand charge transfer state (.sup.3MLCT) of Compounds 1, 2, 3, and 10 were evaluated by using the DFT method of Gaussian program which was structurally optimized at a B3LYP/6-311 G (d,p) level, and the results thereof are shown in Table 1. Ti energy level can be converted from eV to wavelength in nm using the formula: A(nm)=1240/energy level(eV).

TABLE-US-00001 TABLE 1 Presence Compound T.sub.1 energy ratio of No. E.sub.HOMO (eV) E.sub.LUMO (eV) level (nm) .sup.3MLCT (%) 1 5.3 1.37 444 14.64 2 5.42 1.39 445 18.07 3 5.32 1.36 440 19.22 10 4.92 1.48 470 18.59

Example 1

[0725] As an anode, a glass substrate (product of Corning Inc.) with a 15 ohm per square centimeter (/cm.sup.2) (1,200 angstrom ()) ITO formed thereon was cut to a size of 50 millimeter (mm)50 mm0.7 mm, sonicated by using isopropyl alcohol and pure water each for 5 minutes, washed by irradiation of ultraviolet rays and exposure of ozone thereto for 30 minutes, and then mounted on a vacuum deposition apparatus.

[0726] 2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 . 4,4-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter, referred to as NPB) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 .

[0727] Compound 1, Compound DFD29, Compound HTH29, and Compound ETH2 were vacuum-deposited on the hole transport layer to form an emission layer having a thickness of 350 . In this regard, the amount of Compound 1 was 13 parts by weight based on 100 parts by weight of the emission layer, and the amount of Compound DFD29 was 0.4 parts by weight based on 100 parts by weight of the emission layer. The weight ratio of Compound HTH29 to Compound ETH2 was 6.5:3.5.

[0728] Compound HBL-1 was vacuum-deposited on the emission layer to form a hole blocking layer having a thickness of 50 .

[0729] CNNPTRZ and LiQ were vacuum-deposited on the hole blocking layer to form an electron transport layer having a thickness of 310 . In this regard, the weight ratio of CNNPTRZ to LiQ was 4:6.

[0730] Yb was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 15 .

[0731] Mg was vacuum-deposited on the electron injection layer to form a cathode having a thickness of 800 , thereby completing the manufacture of a light-emitting device.

##STR00208## ##STR00209##

Examples 2 to 4 and Comparative Example 1

[0732] Organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that compounds used in forming an emission layer were changed as shown in Table 2.

Evaluation Example 1

[0733] The luminescence efficiency (candela per ampere (cd/A)) at 1000 candela per square meter (cd/m.sup.2) and maximum emission wavelength (nanometer (nm)) of the light-emitting devices manufactured according to Examples 1 to 4 and Comparative Example 1 were measured by using Keithley MU 236 and luminance meter PR650, and the results thereof are shown in Table 2.

[0734] The luminescence efficiency values in Table 2 are shown as relative values (%) of the luminescence efficiency in Examples 1 to 4 based on the luminescence efficiency (100%) of Comparative Example 1.

TABLE-US-00002 TABLE 2 Maximum Luminescence emission Organometallic efficiency wavelength compound (%) (nm) Example 1 1 134 459 Example 2 2 165 460 Example 3 3 175 455 Example 4 10 170 485 Comparative CE1 100 475 Example 1 [00210][00211][00212][00213][00214]

[0735] From Table 2, it was confirmed that the organic light-emitting devices according to Examples 1 to 4 emitted blue light and had higher luminescence efficiency, compared to the organic light-emitting device according to Comparative Example 1.

[0736] According to the one or more embodiments, by using an organometallic compound, a light-emitting device having reduced driving voltage, improved color purity and luminescence efficiency, and increased lifetime and a high-quality electronic apparatus including the light-emitting device may be manufactured. That is, based on one or more embodiments, utilizing the organometallic compound should result in the production of the light-emitting device with lower driving voltage, enhanced color purity and efficiency, extended lifespan, and the high-quality electronic apparatus incorporating this light-emitting device.

[0737] In the context of the present application and unless otherwise defined, the terms use, using, and used may be considered synonymous with the terms utilize, utilizing, and utilized, respectively.

[0738] A person of ordinary skill in the art, in view of the present disclosure in its entirety, would appreciate that each suitable feature of the one or more suitable embodiments of the present disclosure may be combined or combined with each other, partially or entirely, and may be technically interlocked and operated in one or more suitable ways, and each embodiment may be implemented independently of each other or in conjunction with each other in any suitable manner unless otherwise stated or implied.

[0739] It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in one or more embodiments. While one or more embodiments have been described with reference to the drawings, it will be understood by those of ordinary skill in the art that one or more suitable changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and equivalents thereof.