LIGHT-EMITTING DEVICE AND ELECTRONIC APPARATUS AND ELECTRONIC EQUIPMENT INCLUDING THE LIGHT-EMITTING DEVICE

Abstract

A light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes a first compound, a second compound, a transition metal-containing compound, and a delayed fluorescence compound, the first compound being a hole transport material, and the second compound being an electron transport material, the first compound and the second compound form an exciplex, the first compound, the second compound, or any combination thereof is substituted with at least one deuterium, and an absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant of a mixture of the first compound and the second compound is decreased, compared to a case in which the first compound, the second compound, or any combination thereof is not substituted with deuterium.

Claims

1. A light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and comprising an emission layer, wherein the emission layer comprises a first compound, a second compound, a transition metal-containing compound, and a delayed fluorescence compound, the first compound being a hole transport material, and the second compound being an electron transport material, the first compound and the second compound form an exciplex, the first compound, the second compound, or any combination thereof is substituted with at least one deuterium, and an absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant of a mixture of the first compound and the second compound is less compared to a case in which the first compound, the second compound, or any combination thereof is not substituted with deuterium.

2. The light-emitting device of claim 1, wherein the first compound, the second compound, or any combination thereof each has a deuterium substitution rate of 100%.

3. The light-emitting device of claim 1, wherein the triplet charge transfer state-singlet ground state non-radiative decay rate constant is expressed as an average decay time according to multi-exponential decay function fitting in a time-resolved photoluminescence graph of the mixture of the first compound and the second compound.

4. The light-emitting device of claim 3, wherein the average decay time is greater than 4.5 ?s.

5. The light-emitting device of claim 1, wherein, in a corresponding one of the first compound or the second compound, the at least one deuterium is at least substituted at a position at which orbitals involved in exciplex formation are distributed.

6. The light-emitting device of claim 5, wherein the orbitals involved in the exciplex formation are located at an electron donor moiety or an electron acceptor moiety in the corresponding one of the first compound or the second compound.

7. The light-emitting device of claim 1, wherein the first compound comprises a group represented by Formula 1: ##STR00169## and wherein, in Formula 1, 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 comprised in a remaining portion of the first compound other than the group represented by Formula 1.

8. The light-emitting device of claim 7, wherein the group represented by Formula 1 is substituted with the at least one deuterium.

9. The light-emitting device of claim 7, wherein the first compound is at least one selected from Compounds HT01 to HT09: ##STR00170##

10. The light-emitting device of claim 1, wherein the second compound comprises at least one ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

11. The light-emitting device of claim 10, wherein the ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group is substituted with the at least one deuterium.

12. The light-emitting device of claim 10, wherein the second compound is at least one selected from Compounds ET01 to ET12: ##STR00171## ##STR00172## ##STR00173##

13. The light-emitting device of claim 1, wherein the transition metal-containing compound is represented by Formula 3: ##STR00174## and wherein, in Formula 3, 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.901 to X.sub.904 are each independently C or N, ring CY.sub.901 to ring CY.sub.904 are each independently a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group, L.sub.901 to L.sub.903 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(?O)*, *C(?S)*, *C?C*, *B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(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 indicating a binding site to a neighboring atom, n901 to n903 are each independently an integer from 1 to 5, R.sub.901 to R.sub.904, 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.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), a901 to a904 are each independently an integer from 1 to 10, 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, 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, or a C.sub.6-C.sub.60 arylthio 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, 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 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), 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; or a C.sub.3-C.sub.60 carbocyclic group or a C.sub.1-C.sub.6 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.

14. The light-emitting device of claim 13, wherein the transition metal-containing compound is at least one selected from Compounds BD01 to BD16: ##STR00175## ##STR00176## ##STR00177##

15. The light-emitting device of claim 1, wherein the delayed fluorescence compound is a compound comprising at least one cyclic group comprising boron (B) and nitrogen (N) as ring-forming atoms.

16. The light-emitting device of claim 15, wherein the delayed fluorescence compound is at least one selected from Compounds DFD01 to DFD12: ##STR00178## ##STR00179## ##STR00180##

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

18. The electronic apparatus of claim 17, 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.

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

20. The electronic equipment of claim 19, wherein the electronic equipment is at least one of 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 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 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, or a signboard.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of the present disclosure. The drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain principles of the present disclosure. The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0018] FIG. 1 is a schematic view of a structure of a light-emitting device according to one or more embodiments of the present disclosure;

[0019] FIG. 2 is a schematic view of a structure of an electronic apparatus according to one or more embodiment of the present disclosure;

[0020] FIG. 3 is a schematic view of a structure of an electronic apparatus according to one or more embodiments of the present disclosure;

[0021] FIGS. 4, 5, 6A, 6B, and 6C are each a schematic view of a structure of electronic equipment according to one or more embodiments of the present disclosure;

[0022] FIG. 7 shows a time-resolved photoluminescence (PL) graph at 25? C. of each of a mixture including a first compound and a second compound, in which at least one is substituted with deuterium, at a mixing ratio of 1:1 by weight and a mixture including the first compound and the second compound that are not substituted with deuterium at a mixing ratio of 1:1 by weight, according to one or more embodiments of the present disclosure; and

[0023] FIG. 8 shows a PL graph at room temperature (300 K) ((a) of FIG. 8) and a PL graph at cryogenic temperature (4 K) ((b) of FIG. 8) of each of a first compound, a second compound, a mixture including the first compound and the second compound, in which at least one is substituted with deuterium, at a mixing ratio of 1:1 by weight, and a mixture including the first compound and the second compound that are not substituted with deuterium at a mixing ratio of 1:1 by weight, according to one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

[0024] Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout the present disclosure, and duplicative descriptions thereof may not be provided for conciseness. In this regard, the embodiments of the present disclosure may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments of the present disclosure are merely described, by referring to the drawings, to explain aspects of the present disclosure. As utilized herein, the term and/or or or may include any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expressions such as at least one of, one of, and selected from, when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, at least one of a, b or c, at least one selected from a, b, and c, at least one selected from among a to c, etc., may indicate 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. The / utilized herein may be interpreted as and or as or depending on the situation.

[0025] According to one or more embodiments of the present disclosure, a light-emitting device may include: [0026] a first electrode; [0027] a second electrode facing the first electrode; and [0028] an interlayer between the first electrode and the second electrode and including an emission layer, [0029] wherein the emission layer may include a first compound, a second compound, a transition metal-containing compound, and a delayed fluorescence compound, the first compound being a hole transport material, and the second compound being an electron transport material, [0030] the first compound and the second compound form an exciplex, [0031] the first compound, the second compound, or any combination thereof is substituted with at least one deuterium, and [0032] due to the substitution of the first compound, the second compound, or any combination thereof with the at least one deuterium, an absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant of a mixture of the first compound and the second compound is decreased (e.g., less), compared to a case (e.g., an embodiment) in which the first compound, the second compound, or any combination thereof is not substituted with deuterium.

[0033] The term triplet charge transfer state-singlet ground state non-radiative decay rate constant as utilized herein refers to a rate constant for a non-radiative decay from a triplet charge transfer state (3CT) to a singlet ground state, among energy states of the mixture of the first compound and the second compound. The triplet charge transfer state and/or the singlet ground state may be an energy state formed when the first compound and the second compound are mixed to form an exciplex.

[0034] In one or more embodiments, the triplet charge transfer state-singlet ground state non-radiative decay rate constant may be expressed as a decay section slope in a time-resolved photoluminescence (PL) graph. The decay section slope may be expressed as, for example, an average slope of a decay section, an average slope of a specific area in a decay section, an instantaneous slope of a decay section at specific time coordinates, a maximum or minimum value of an instantaneous slope of a decay section, and/or the like. Here, the average slope may be an average slope of PL intensity from time coordinates indicating maximum emission (e.g., maximum emission intensity) to end time coordinates (e.g., the total measured/recorded time coordinates).

[0035] In one or more embodiments, the triplet charge transfer state-singlet ground state non-radiative decay rate constant may be expressed as an average decay time according to multi-exponential decay function fitting in a time-resolved PL graph. In this regard, when the absolute value of the triplet charge transfer state-singlet ground state non-radiative decay rate constant decreases, the average decay time may increase, and when the absolute value of the triplet charge transfer state-singlet ground state non-radiative decay rate constant increases, the average decay time may decrease. The multi-exponential decay function fitting may be performed on time-dependent PL intensity data obtained from, for example, a curved time-resolved PL graph. The multi-exponential decay function fitting may be performed by utilizing a suitable method. For a suitable method, <J?rg Enderlein and Rainer Erdmann. (1997). Fast fitting of multi-exponential decay curves. Optics Communications. 134(1), 371-378>, Japanese Patent Application Publication No. 1998-078398 A, and/or the like may be referred to, the entire content of each of which is incorporated herein by reference. However, embodiments of the present disclosure are not limited thereto, and all suitable methods may be applied to the multi-exponential decay function fitting.

[0036] In one or more embodiments, the average decay time may be greater than 4.5 ?s. For example, in some embodiments, the average decay time may be 4.6 ?s or more, 4.65 ?s or more, 4.7 ?s or more, 4.75 ?s or more, 4.8 ?s or more, 4.85 ?s or more, 4.9 ?s or more, or 4.95 ?s or more.

[0037] In one or more embodiments, the average decay time may be in a range of: about 4.6 ?s to about 20 ?s, about 4.65 ?s to about 20 ?s, about 4.7 ?s to about 20 ?s, about 4.75 ?s to about 20 ?s, about 4.8 ?s to about 20 ?s, about 4.85 ?s to about 20 ?s, about 4.9 ?s to about 20 ?s, or about 4.95 ?s to about 20 ?s; about 4.6 ?s to about 15 ?s, about 4.65 ?s to about 15 ?s, about 4.7 ?s to about 15 ?s, about 4.75 ?s to about 15 ?s, about 4.8 ?s to about 15 ?s, about 4.85 ?s to about 15 ?s, about 4.9 ?s to about 15 ?s, or about 4.95 ?s to about 15 ?s; about 4.6 ?s to about 10 ?s, about 4.65 ?s to about 10 ?s, about 4.7 ?s to about 10 ?s, about 4.75 ?s to about 10 ?s, about 4.8 ?s to about 10 ?s, about 4.85 ?s to about 10 ?s, about 4.9 ?s to about 10 ?s, or about 4.95 ?s to about 10 ?s; about 4.6 ?s to about 8 ?s, about 4.65 ?s to about 8 ?s, about 4.7 ?s to about 8 ?s, about 4.75 ?s to about 8 ?s, about 4.8 ?s to about 8 ?s, about 4.85 ?s to about 8 ?s, about 4.9 ?s to about 8 ?s, or about 4.95 ?s to about 8 ?s; about 4.6 ?s to about 7 ?s, about 4.65 ?s to about 7 ?s, about 4.7 ?s to about 7 ?s, about 4.75 ?s to about 7 ?s, about 4.8 ?s to about 7 ?s, about 4.85 ?s to about 7 ?s, about 4.9 ?s to about 7 ?s, or about 4.95 ?s to about 7 ?s; about 4.6 ?s to about 6 ?s, about 4.65 ?s to about 6 ?s, about 4.7 ?s to about 6 ?s, about 4.75 ?s to about 6 ?s, about 4.8 ?s to about 6 ?s, about 4.85 ?s to about 6 ?s, about 4.9 ?s to about 6 ?s, or about 4.95 ?s to about 6 ?s; or about 4.6 ?s to about 5.5 ?s, about 4.65 ?s to about 5.5 ?s, about 4.7 ?s to about 5.5 ?s, about 4.75 ?s to about 5.5 ?s, about 4.8 ?s to about 5.5 ?s, about 4.85 ?s to about 5.5 ?s, about 4.9 ?s to about 5.5 ?s, or about 4.95 ?s to about 5.5 ?s.

[0038] According to one or more embodiments, FIG. 7 shows a time-resolved PL graph at 25? C. of a mixture including Compounds HT08 and ET08 at a ratio of 1:1, wherein Graph (1), i.e., curve (1), is a graph of an embodiment in which Compound HT08 is substituted with deuterium (substitution rate: 100%), and Graph (2), i.e., curve (2) is a graph of an embodiment in which Compound HT08 is not substituted with deuterium (substitution rate: 0%). According to the time-resolved PL graph of FIG. 7, PL intensity gradually decreases over time after reaching a maximum value, and a slope (e.g., an average rate of change or an instantaneous rate of change) of a decay section in which the PL intensity decreases may correspond to a triplet charge transfer state-singlet ground state non-radiative decay rate constant of the mixture of HT08 and ET08.

[0039] In one or more embodiments, the first compound, the second compound, or any combination thereof may each have a deuterium substitution rate of 50% or more.

[0040] The term deuterium substitution rate as utilized herein refers to a ratio of positions actually substituted with deuterium out of all positions available for substitution (e.g., all positions of hydrogen) in each compound. For example, when Compound HT01 described herein is substituted with 16 deuterium atoms, Compound HT01 has a deuterium substitution rate of 80%.

[0041] In one or more embodiments, the first compound, the second compound, or any combination thereof may each have a deuterium substitution rate of 100%.

[0042] In one or more embodiments, the first compound may be substituted with deuterium, and the first compound may have a deuterium substitution rate of 100%.

[0043] In one or more embodiments, the second compound may be substituted with deuterium, and the second compound may have a deuterium substitution rate of 100%.

[0044] In one or more embodiments, the first compound and the second compound may both (e.g., simultaneously) be substituted with deuterium, and the first compound and the second compound may each have a deuterium substitution rate of 100%.

[0045] In one or more embodiments, the light-emitting device may have a PL quantum yield (PLQY) value of 103% or more, compared to (e.g., relative to) a light-emitting device including the first compound and the second compound that are not substituted with deuterium in an emission layer. For example, in some embodiments, the light-emitting device may have a PLQY value in a range of about 103% to about 150%, about 104% to about 150%, or about 105% to about 150%, compared to (e.g., relative to) a light-emitting device including the first compound and the second compound that are not substituted with deuterium in an emission layer.

[0046] In one or more embodiments, the light-emitting device may have a device lifespan value of 120% or more, compared to (e.g., relative to) a light-emitting device including the first compound and the second compound that are not substituted with deuterium in an emission layer. In this regard, the lifespan value may be based on the time (LT95) taken until the luminance declines to 95% of the initial luminance. For example, in some embodiments, the light-emitting device may have a device lifespan value in a range of about 120% to about 250%, about 125% to about 250%, or about 130% to about 250%, compared to (e.g., relative to) a light-emitting device including the first compound and the second compound that are not substituted with deuterium in an emission layer.

[0047] In one or more embodiments, the increase in PLQY or the increase in device lifespan may be due to a decrease in the absolute value of the triplet charge transfer state-singlet ground state non-radiative decay rate constant, rather than a decrease in the singlet-triplet energy level difference of the mixture of the first compound and the second compound.

[0048] For example, FIG. 7 shows a time-resolved PL graph at 25? C. of a mixture including Compounds HT08 and ET08 at a mixing ratio of 1:1 by weight, wherein Graph (1), i.e., curve (1) is a graph of an embodiment in which Compound HT08 is substituted with deuterium (substitution rate: 100%), and Graph (2), i.e., curve (2) is a graph of an embodiment in which Compound HT08 is not substituted with deuterium (substitution rate: 0%). According to the time-resolved PL graph of FIG. 7, it may be confirmed that due to the substitution of HT08 with deuterium, the absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant (which is expressed by a slope of a decay section) of the mixture of HT08 and ET08 is decreased compared to the embodiment in which HT08 is not substituted with deuterium.

[0049] In one or more embodiments, FIG. 8 shows a PL graph at room temperature (300 K) ((a) of FIG. 8) and a PL graph at a cryogenic temperature (4 K) ((b) of FIG. 8). In (a) and (b) of FIG. 8, Graph (1), i.e., curve (1), shows a PL graph of an embodiment in which HT08 is utilized alone as the first compound, Graph (2), i.e., curve (2), shows a PL graph of an embodiment in which ET08 is utilized alone as the second compound, Graph (3), i.e., curve (3), shows a PL graph of an embodiment in which a mixture including HT08 and ET08 at a mixing ratio of 1:1 by weight is utilized and HT08 is substituted with deuterium (substitution rate: 100%), and Graph (4), i.e., curve (4), shows a PL graph of an embodiment in which a mixture including HT08 and ET08 at a mixing ratio of 1:1 by weight is utilized and HT08 is not substituted with deuterium (substitution rate: 0%). A PL graph at room temperature represents an energy level in a singlet state, and a PL graph at a cryogenic temperature represents an energy level in a triplet state. Comparing (a) of FIG. 8 with (b) of FIG. 8, it may be confirmed that, regardless of the presence or absence of deuterium substitution, because wavelengths of light respectively emitted from singlet and triplet states of the mixture of HT08 and ET08 are substantially the same, energy levels in the singlet and triplet states of the mixture of HT08 and ET08 are substantially the same. For example, it may be confirmed that a singlet-triplet energy level difference remains substantially the same despite deuterium substitution.

[0050] In one or more embodiments, in each (e.g., a corresponding one) of the first compound, the second compound, or any combination thereof, the deuterium may at least be substituted at a position at which orbitals involved in exciplex formation are distributed.

[0051] In one or more embodiments, the orbitals involved in the exciplex formation may be located at an electron donor moiety or an electron acceptor moiety in the first compound or the second compound (e.g., the corresponding one of the first compound or the second compound).

[0052] For example, the electron doner moiety may be a ? electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group, and the electron acceptor moiety may be a ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group. For example, in one or more embodiments, the first compound may include, as an electron doner moiety, a ? electron-rich C.sub.3-C.sub.60 cyclic group or a pyridine group, and the ? electron-rich C.sub.3-C.sub.60 cyclic group or the pyridine group may be substituted with at least one deuterium. For example, in one or more embodiments, the second compound may include, as an electron acceptor moiety, a ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group, and the ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group may be substituted with at least one deuterium.

[0053] In one or more embodiments, the first compound may include a group represented by Formula 1:

##STR00001##

[0054] In Formula 1, [0055] 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, [0056] X.sub.71 may be a single bond, or a linking group including O, S, N, B, C, Si, or any combination thereof, and [0057] * indicates a binding site to any atom included in a remaining portion of the first compound other than the group represented by Formula 1.

[0058] In one or more embodiments, the group represented by Formula 1 may be substituted with at least one deuterium.

[0059] In one or more embodiments, the first compound may include a compound represented by Formula 1-1, a compound represented by Formula 1-2, a compound represented by Formula 1-3, a compound represented by Formula 1-4, a compound represented by Formula 1-5, or any combination thereof:

##STR00002## ##STR00003##

[0060] In Formulae 1-1 to 1-5, [0061] 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, [0062] 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), [0063] 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), [0064] 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), [0065] X.sub.85 may be C or Si, [0066] 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 may each be the same as described with respect to Q.sub.1, [0067] b81 to b85 may each independently be an integer from 1 to 5, [0068] 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 may each be the same as described elsewhere herein, [0069] a71 to a74 may each independently be an integer from 0 to 20, and [0070] R.sub.10a may be the same as described herein.

[0071] In one or more embodiments, the second compound may include at least one ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

[0072] 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.

[0073] In one or more embodiments, the ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group may be substituted with at least one deuterium.

[0074] In one or more embodiments, the second compound may include a compound represented by Formula 2:

##STR00004##

[0075] In Formula 2, [0076] 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, [0077] b51 to b53 may each independently be an integer from 1 to 5, [0078] 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 selected from among X.sub.54 to X.sub.56 may be N, and [0079] R.sub.51 to R.sub.56 and R.sub.10a may each be the same as described herein.

[0080] In one or more embodiments, the transition metal-containing compound may be represented by Formula 3:

##STR00005##

[0081] Details on Formula 3 may be the same as described elsewhere herein.

[0082] In one or more embodiments, the delayed fluorescence compound may be a compound including at least one cyclic group including boron (B) and nitrogen (N) as ring-forming atoms.

[0083] In one or more embodiments, a difference between a triplet energy level (eV) of the delayed fluorescence compound and a singlet energy level (eV) of the delayed fluorescence compound may be 0 eV or more and 0.5 eV or less (or, 0 eV or more and 0.3 eV or less).

[0084] In one or more embodiments, the delayed fluorescence compound may be a C.sub.8-C.sub.60 polycyclic group-containing compound including at least two condensed cyclic groups that share B (e.g., one being a first ring and another being a second ring).

[0085] In one or more embodiments, the delayed fluorescence compound may include a condensed ring in which at least one third ring is condensed with at least one fourth ring, for example, to form the condensed ring including four or more rings, [0086] the third ring of the delayed fluorescence compound 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 of the delayed fluorescence compound 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 delayed fluorescence compound may include a compound represented by Formula 502, a compound represented by Formula 503, or any combination thereof:

##STR00006##

[0089] In Formulae 502 and 503, [0090] 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, [0091] 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), [0092] 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), [0093] 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), [0094] 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), [0095] Y.sub.51 and Y.sub.52 may each independently be B, P(?O), or S(?O), [0096] 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 may each be the same as described elsewhere herein, and [0097] a501 to a504 may each independently be an integer from 0 to 20.

[0098] In one or more embodiments, the emission layer may include a host and a dopant, wherein the first compound and the second compound may be included in the host, and the transition metal-containing compound and the delayed fluorescence compound may be included in the dopant.

[0099] In one or more embodiments, the emission layer may include a host, a dopant, and an auxiliary dopant, wherein the first compound and the second compound may be included in the host, the delayed fluorescence compound may be included in the dopant, and the transition metal-containing compound may be included in the auxiliary dopant.

[0100] In one or more embodiments, the emission layer may include a host, an emitter, and a dopant, wherein the first compound and the second compound may be included in the host, the transition metal-containing compound may be included in the emitter, and the delayed fluorescence compound may be included in the dopant.

[0101] In the present disclosure, the auxiliary dopant may serve to transfer energy to the dopant (or the emitter).

[0102] In one or more embodiments, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof may include at least one deuterium.

[0103] In one or more embodiments, the first electrode may be an anode, the second electrode may be a cathode, [0104] 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, [0105] 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 [0106] the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof. [0107] 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. For example, the hole blocking layer may directly contact the emission layer.

[0108] In one or more embodiments, the emission layer may be to emit red light, green light, blue light, and/or white light (e.g., combined white light). For example, in some embodiments, 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 400 nm to about 490 nm.

[0109] In one or more embodiments, the emission layer may be to emit blue light. For example, the emission layer may be to emit light having a maximum emission wavelength in a range of about 430 nm to about 480 nm.

[0110] In one or more embodiments, the blue light may have a maximum emission wavelength in a range of 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.

[0111] In one or more embodiments, the light-emitting device may satisfy at least one condition selected from among Conditions 1 to 4:

Condition 1

[0112] lowest unoccupied molecular orbital (LUMO) energy level (eV) of first compound>LUMO energy level (eV) of transition metal-containing compound

Condition 2

[0113] LUMO energy level (eV) of transition metal-containing compound>LUMO energy level (eV) of second compound

Condition 3

[0114] highest occupied molecular orbital (HOMO) energy level (eV) of transition metal-containing compound>HOMO energy level (eV) of first compound

Condition 4

[0115] HOMO energy level (eV) of first compound>HOMO energy level (eV) of second compound.

[0116] Each of the HOMO energy level and LUMO energy level of each of the first compound, the second compound, and the transition metal-containing compound may be a negative value, and may be measured according to a suitable method.

[0117] In one or more embodiments, an absolute value of a difference between the LUMO energy level of the transition metal-containing compound and the LUMO energy level of the second compound may be about 0.1 eV or more and about 1.0 eV or less or an absolute value of a difference between the LUMO energy level of the transition metal-containing compound and the LUMO energy level of the first compound may be about 0.1 eV or more and about 1.0 eV or less, and an absolute value of a difference between the HOMO energy level of the transition metal-containing compound and the HOMO energy level of the second compound may be about 1.25 eV or less (e.g., about 1.25 eV or less and about 0.2 eV or more) or an absolute value of a difference between the HOMO energy level of the transition metal-containing compound and the HOMO energy level of the first compound may be about 1.25 eV or less (e.g., about 1.25 eV or less and about 0.2 eV or more).

[0118] When the relationships between LUMO energy level and HOMO energy level satisfy the conditions as described above, a balance between holes and electrons injected into the emission layer may be achieved.

[0119] The light-emitting device may have a structure as described herein.

Embodiments

[0120] According to one or more embodiments, the emission layer of the light-emitting device may include a host, a dopant (or an emitter), and an auxiliary dopant, wherein the first compound and the second compound may be included in the host, the delayed fluorescence compound may be included in the dopant (or the emitter), the transition metal-containing compound may be included in the auxiliary dopant, and the emission layer may be to emit phosphorescence or fluorescence (e.g., delayed fluorescence) emitted from the dopant (or the emitter).

[0121] For example, in one or more embodiments, the phosphorescence or fluorescence emitted from the dopant (or the emitter) may be blue phosphorescence or blue fluorescence (e.g., blue delayed fluorescence).

[0122] 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.

[0123] In one or more embodiments, the light-emitting device may further include a capping layer arranged outside (e.g., on) the first electrode and/or outside (e.g., on) the second electrode.

[0124] In one or more embodiments, the light-emitting device may further include at least one of a first capping layer arranged outside (e.g., on) the first electrode or a second capping layer arranged outside (e.g., on) the second electrode. At least one of the first capping layer or the second capping layer may include the first compound, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof. More details on the first capping layer and/or the second capping layer may be the same as described herein.

[0125] In one or more embodiments, the light-emitting device may include: [0126] a first capping layer arranged outside (e.g., on) the first electrode and including the first compound, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof; [0127] a second capping layer arranged outside (e.g., on) the second electrode and including the first compound, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof; or [0128] the first capping layer and the second capping layer.

[0129] The expression (an interlayer and/or a capping layer) includes the first compound (or, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof) as utilized herein may include an embodiment in which (an interlayer and/or a capping layer) includes one kind or type of the first compound (or, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof) and an embodiment in which (an interlayer and/or a capping layer) includes two or more different kinds or types of the first compound (or, the second compound, the transition metal-containing compound, the delayed fluorescence compound, or any combination thereof).

[0130] For example, in some embodiments, the interlayer and/or the capping layer may include Compound HT01 only as the first compound. In this regard, Compound HT01 may be present in the emission layer of the light-emitting device. In some embodiments, the interlayer may include, as the first compound, Compound HT01 and Compound HT02. In this regard, Compound HT01 and Compound HT02 may be present in substantially the same layer (e.g., both (e.g., simultaneously) Compound HT01 and Compound HT02 may be present in the emission layer), or may be present in different layers (e.g., Compound HT01 may be present in the emission layer, and Compound HT02 may be present in the electron transport region).

[0131] The term interlayer as utilized herein refers to a single layer and/or all of multiple layers between the first electrode and the second electrode of the light-emitting device.

[0132] One or more aspects of embodiments of the present disclosure are directed toward an electronic apparatus including the light-emitting device. In one or more embodiments, 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 of the thin-film transistor. In some 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 the same as described herein.

[0133] One or more aspects of embodiments of the present disclosure are directed toward electronic equipment including the light-emitting device.

[0134] For example, the electronic equipment may be at least one of 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 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 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, or a signboard.

[0135] Methods of substituting the first compound, the second compound, or any combination thereof with deuterium may be recognized by one of ordinary skill in the art by referring to Synthesis Examples and/or Examples provided herein.

[0136] In the light-emitting device, the emission layer may include the first compound that is a hole transport material, the second compound that is an electron transport material, the transition metal-containing compound, and the delayed fluorescence compound, and the first compound, the second compound, or any combination thereof may be substituted with at least one deuterium. Due to the substitution of the first compound, the second compound, or any combination thereof with deuterium, the absolute value of a triplet charge transfer state-singlet ground state non-radiative decay rate constant of a mixture of the first compound and the second compound may be decreased, compared to a case (e.g., embodiments) in which the first compound, the second compound, or any combination thereof is not substituted with deuterium. Due to the decrease in the absolute value of the triplet charge transfer state-singlet ground state non-radiative decay rate constant, the light-emitting device may have increased luminescence efficiency and lifespan. Accordingly, by utilizing the light-emitting device, an electronic device having characteristics of low driving voltage, high efficiency, and long lifespan may be implemented.

Description of Formulae

[0137] ##STR00007##

[0138] In Formula 1, 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.

[0139] In Formula 1, X.sub.71 may be a single bond, or a linking group including O, S, N, B, C, Si, or any combination thereof.

[0140] In Formula 1, * indicates a binding site to any atom included in a remaining portion of the first compound other than the group represented by Formula 1.

##STR00008## ##STR00009##

[0141] In Formulae 1-1 to 1-5, 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.

[0142] In Formulae 1-1 to 1-5, 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).

[0143] In Formulae 1-1 to 1-5, 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).

[0144] In Formulae 1-1 to 1-5, 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).

[0145] In Formulae 1-1 to 1-5, X.sub.85 may be C or Si.

[0146] In Formulae 1-1 to 1-5, 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.

[0147] Q.sub.4 and Q.sub.5 may each be the same as described with respect to Q.sub.1.

[0148] In Formulae 1-1 to 1-5, b81 to b85 may each independently be an integer from 1 to 5.

[0149] In Formulae 1-1 to 1-5, 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 may each be the same as described herein.

[0150] In Formulae 1-1 to 1-5, 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 (s) may be identical to or different from each other, when a72 is 2 or more, two or more of R.sub.72(s) may be identical to or different from each other, when a73 is 2 or more, two or more of R.sub.73(s) may be identical to or different from each other, and when a74 is 2 or more, two or more of R.sub.74(s) may be identical to or different from each other. In some embodiments, a71 to a74 may each independently be an integer from 0 to 8.

[0151] R.sub.10a may be the same as described herein.

[0152] In Formulae 1-1 to 1-5, L.sub.81 to L.sub.85 may each independently be: [0153] a single bond; [0154] *C(Q.sub.4)(Q.sub.5)-* or *Si(Q.sub.4)(Q.sub.5)-*; or [0155] 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 [0156] 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.

[0157] In one or more embodiments, a group represented by

##STR00010##

in Formulae 1-1 and 1-2 may be a group represented by one selected from among Formulae CY71-1(1) to CY71-1(8), and/or [0158] a group represented by

##STR00011## in Formulae 1-1 and 1-3 may be a group represented by one selected from among Formulae CY71-2(1) to CY71-2(8), and/or [0159] a group represented by

##STR00012## in Formulae 1-2 and 1-4 may be a group represented by one selected from among Formulae CY71-3(1) to CY71-3(32), and/or [0160] a group represented by

##STR00013## in Formulae 1-3 to 1-5 may be a group represented by one selected from among Formulae CY71-4(1) to CY71-4(32), and/or [0161] a group represented by

##STR00014## in Formula 1-5 may be a group represented by one selected from among Formulae CY71-5(1) to CY71-5(8):

##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##

[0162] 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), [0163] X.sub.81 to X.sub.85, L.sub.81, b81, R.sub.81, and R.sub.85 may each be the same as described herein, [0164] 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), [0165] 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), [0166] in Formulae CY71-1(1) to CY71-1(8) and 71-4(1) to CY71-4(32), each of X.sub.86 and X.sub.87 may not be a single bond at the same time, [0167] 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.86a)(R.sub.86b), [0168] 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), [0169] in Formulae CY71-2(1) to CY71-2(8), CY71-3(1) to CY71-3(32), and CY71-5(1) to CY71-5(8), each of X.sub.88 and X.sub.89 may not be a single bond at the same time, and [0170] 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 may each be the same as described with respect to R.sub.81.

##STR00026##

[0171] 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.

[0172] In Formula 2, b51 to b53 indicate the number of L.sub.51 to the number of 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 (s) may be identical to or different from each other, when b52 is 2 or more, two or more of L.sub.52(s) may be identical to or different from each other, and when b53 is 2 or more, two or more of L.sub.53(s) may be identical to or different from each other. For example, in some embodiments, b51 to b53 may each independently be 1 or 2.

[0173] In Formula 2, in one or more embodiments, L.sub.51 to L.sub.53 may each independently be: [0174] a single bond; or [0175] 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 dibenzooxasiline 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 dibenzodithiine 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 [0176] 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.

[0177] In one or more embodiment, 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 L.sub.51(s), a bond between two L.sub.52(s), a bond between two L.sub.53(s), 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.

[0178] 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), X.sub.56 may be N or C(R.sub.56), and at least one selected from X.sub.54 to X.sub.56 may be N. R.sub.54 to R.sub.56 may each be the same as described herein. For example, in some embodiments, two or three selected from X.sub.54 to X.sub.56 may each be N.

[0179] 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.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 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 may each be the same as described herein.

[0180] In Formula 2, in one or more embodiments, R.sub.51 to R.sub.56 may each independently be: [0181] 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; [0182] 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; [0183] 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.20alkyl group, a C.sub.1-C.sub.20alkoxy 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 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 [0184] 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 [0185] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: [0186] 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 [0187] 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.

##STR00027##

[0188] In Formula 91, [0189] 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, [0190] X.sub.91 may be a single bond, O, S, N(R.sub.91), B(R.sub.91), C(R.sub.91a)(R.sub.11b), or Si(R.sub.91a)(R.sub.91b), [0191] R.sub.11, R.sub.11a, and R.sub.91b may be the same as described with respect to R.sub.82, R.sub.82a, and R.sub.82b, respectively, [0192] R.sub.10a may be the same as described herein, and [0193] * indicates a binding site to a neighboring atom.

[0194] For example, in some embodiments, in Formula 91, [0195] ring CY.sub.91 and ring CY.sub.92 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 [0196] R.sub.11, R.sub.11a, and R.sub.91b may each independently be: [0197] hydrogen or a C.sub.1-C.sub.10 alkyl group; or [0198] 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.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.

[0199] In one or more embodiments, 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.

[0200] In one or more embodiments, 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 be identical to each other.

[0201] In one or more embodiments, 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 be different from each other.

[0202] In one or more embodiments, in Formula 2, b51 and b52 may each independently 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.

[0203] For example, in some embodiments, in Formula 2, R.sub.51 and R.sub.52 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.1-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 [0204] 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.

[0205] In one or more embodiments, [0206] a group represented by *-(L.sub.51).sub.b51-R.sub.51 in Formula 2 may be a group represented by one selected from among Formulae CY51-1 to CY51-26, and/or [0207] a group represented by *-(L.sub.52).sub.b52-R.sub.52 in Formula 2 may be a group represented by one selected from among Formulae CY52-1 to CY52-26, and/or [0208] a group represented by *-(L.sub.53).sub.b53-R.sub.53 in Formula 2 may be a group represented by 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):

##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042## ##STR00043## ##STR00044## ##STR00045## [0209] In Formulae CY51-1 to CY51-26, CY52-1 to CY52-26, and CY53-1 to CY53-27, [0210] 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), [0211] 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), [0212] 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.6a)(R.sub.67b), [0213] 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.68a)(R.sub.68b), [0214] 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, [0215] 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, [0216] 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 may each be the same as described with respect to R.sub.51, wherein R.sub.51a to R.sub.51e may not each be hydrogen, [0217] 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 may each be the same as described with respect to R.sub.52, wherein R.sub.52a to R.sub.52e may not each be hydrogen, [0218] R.sub.53a to R.sub.53e, R.sub.69a, and R.sub.69b may each be the same as described with respect to R.sub.53, wherein R.sub.53a to R.sub.53e may not each be hydrogen, and [0219] * indicates a binding site to a neighboring atom.

[0220] For example, in one or more embodiments, [0221] in Formulae CY51-1 to CY51-26 and CY52-1 to 52-26, R.sub.51a to R.sub.51e and R.sub.52a to R.sub.52e may each independently be: [0222] 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 [0223] C(Q.sub.1)(Q.sub.2)(Q.sub.3) or Si(Q.sub.1)(Q.sub.2)(Q.sub.3), [0224] 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, [0225] 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 [0226] 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.

##STR00046##

[0227] In Formula 3, 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).

[0228] In one or more embodiments, M may be Pt.

[0229] In Formula 3, X.sub.901 to X.sub.904 may each independently be C or N.

[0230] In one or more embodiments, X.sub.901 may be C. For example, in some embodiment, in Formula 3, X.sub.901 may be C, and C may be carbon of a carbene moiety.

[0231] In one or more embodiments, in Formula 3, X.sub.901 may be N.

[0232] In one or more embodiments, X.sub.902 and X.sub.903 may each be C, and X.sub.904 may be N.

[0233] In Formula 3, i) a bond between X.sub.901 and M may be a coordinate bond, and ii) one selected from among a bond between X.sub.902 and M, a bond between X.sub.903 and M, and a bond between X.sub.904 and M may be a coordinate bond, and the other two may each be a covalent bond.

[0234] For example, in some embodiments, a bond between X.sub.901 and M and a bond between X.sub.904 and M may each be a coordinate bond, and a bond between X.sub.902 and M and a bond between X.sub.903 and M may each be a covalent bond.

[0235] In one or more embodiments, X.sub.901 may be C, and a bond between X.sub.901 and M may be a coordinate bond.

[0236] In Formula 3, ring CY.sub.901 to ring CY.sub.904 may each independently be a C.sub.5-C.sub.30 carbocyclic group or a C.sub.1-C.sub.30 heterocyclic group.

[0237] For example, in some embodiments, ring CY.sub.901 may be a nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

[0238] In Formula 3, in one or more embodiments, ring CY.sub.901 may be i) an X.sub.901-containing 5-membered ring, ii) an X.sub.901-containing 5-membered ring in which at least one 6-membered ring is condensed, or iii) an X.sub.901-containing 6-membered ring. In one or more embodiments, in Formula 3, ring CY.sub.901 may be i) an X.sub.901-containing 5-membered ring or ii) an X.sub.901-containing 5-membered ring in which at least one 6-membered ring is condensed. For example, in some embodiments, ring CY.sub.901 may include a 5-membered ring bonded to M in Formula 3 via X.sub.901. The X.sub.901-containing 5-membered ring may be 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, or a thiadiazole group, and the X.sub.901-containing 6-membered ring and the 6-membered ring which may be optionally condensed to the X.sub.901-containing 5-membered ring may each independently be a benzene group, a pyridine group, or a pyrimidine group.

[0239] In one or more embodiments, ring CY.sub.901 may be an X.sub.901-containing 5-membered ring, and the X.sub.901-containing 5-membered ring may be an imidazole group or a triazole group.

[0240] In one or more embodiments, ring CY.sub.901 may be an X.sub.901-containing 5-membered ring in which at least one 6-membered ring is condensed, and the X.sub.901-containing 5-membered ring in which at least one 6-membered ring is condensed may be a benzimidazole group or an imidazopyridine group.

[0241] In one or more embodiments, ring CY.sub.901 may be an imidazole group, a triazole group, a benzimidazole group, or an imidazopyridine group.

[0242] In one or more embodiments, X.sub.901 may be C, and ring CY.sub.901 may be an imidazole group, a triazole group, a benzimidazole group, a naphthoimidazole group, or an imidazopyridine group.

[0243] In one or more embodiments, ring CY.sub.902 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.

[0244] For example, in some embodiments, ring CY.sub.902 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.

[0245] In Formula 3, ring CY.sub.903 may be: a C.sub.2-C.sub.8 monocyclic group; or a C.sub.4-C.sub.20 polycyclic group in which two or three C.sub.2-C.sub.8 monocyclic groups are condensed with each other.

[0246] For example, in one or more embodiments, in Formula 3, ring CY.sub.903 may be: a C.sub.4-C.sub.6 monocyclic group; or a C.sub.4-C.sub.8 polycyclic group in which two or three C.sub.4-C.sub.6 monocyclic groups are condensed with each other.

[0247] The term C.sub.2-C.sub.8 monocyclic group as utilized herein refers to a non-condensed cyclic group, and may include, for example, a cyclopentadiene 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 benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a cycloheptadiene group, or a cyclooctadiene group.

[0248] For example, in some embodiments, ring CY.sub.903 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, an azadibenzofuran group, an azadibenzothiophene group, an azacarbazole group, an azafluorene group, or an azadibenzosilole group.

[0249] In Formula 3, ring CY.sub.904 may be a nitrogen-containing C.sub.1-C.sub.60 heterocyclic group.

[0250] For example, in one or more embodiments, ring CY.sub.904 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.

[0251] In Formula 3, L.sub.901 to L.sub.903 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(?O)*, *C(?S)*, *C?C*, *B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(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)*, wherein * and * each indicate a binding site to a neighboring atom.

[0252] R.sub.1a and R.sub.1b may each be the same as described herein.

[0253] In one or more embodiments, L.sub.901 and L.sub.903 may each be a single bond, and L.sub.902 may be *C(R.sub.1a)(R.sub.1b)*, *B(R.sub.1a)*, *N(R.sub.1a)*, *O*, *P(R.sub.1a)*, *Si(R.sub.1a)(R.sub.1b)*, or *S*.

[0254] In one or more embodiments, L.sub.902 may be *O* or *S*.

[0255] In Formula 3, n901 to n903 indicate the number of L.sub.901 to the number of L.sub.903, respectively, and may each independently be an integer from 1 to 5. When each of n901 to n903 is 2 or more, each of two or more of L.sub.901(s), two or more of L.sub.902(s), and/or two or more of L.sub.903(s) may be identical to or different from each other.

[0256] In one or more embodiments, n902 may be 1.

[0257] In Formula 3, R.sub.901 to R.sub.904, R.sub.1a, and R.sub.1b 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.1-C.sub.60 aryloxy group unsubstituted or substituted with at least one R.sub.10a, a C.sub.1-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).

[0258] R.sub.10a, Q.sub.1, Q.sub.2, and Q.sub.3 may each be the same as described herein.

[0259] In one or more embodiments, R.sub.901 to R.sub.904, R.sub.1a, and R.sub.1b may each independently be: [0260] 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; [0261] 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; [0262] 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 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.1 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, 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 [0263] 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). [0264] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each be the same as described herein.

[0265] In one or more embodiments, R.sub.901 to R.sub.904, R.sub.1a, and R.sub.1b may each independently be: [0266] hydrogen, deuterium, F, Cl, Br, I, or a C.sub.1-C.sub.20alkyl group; [0267] a C.sub.1-C.sub.20 alkyl group 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.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; or [0268] a phenyl group, a biphenyl group, a terphenyl group, a (C.sub.1-C.sub.10 alkyl)phenyl group, or a naphthyl 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 C.sub.1-C.sub.20alkyl 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, a (C.sub.1-C.sub.10 alkyl)phenyl group, or any combination thereof.

[0269] In Formula 3, a901 to a904 indicate the number of R.sub.901 to the number of R.sub.904, respectively, and may each independently be an integer from 1 to 10. When each of a901 to a904 is 2 or more, each of two or more of R.sub.901(s) to two or more of R.sub.904(s) may be identical to or different from each other.

##STR00047##

[0270] 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.

[0271] 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).

[0272] 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).

[0273] 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).

[0274] 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).

[0275] In Formulae 502 and 503, Y.sub.51 and Y.sub.52 may each independently be B, P(?O), or S(?O).

[0276] 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 may each be the same as described herein.

[0277] 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(s) may be identical to or different from each other, when a502 is 2 or more, two or more of R.sub.502(s) may be identical to or different from each other, when a503 is 2 or more, two or more of R.sub.503(s) may be identical to or different from each other, and when a504 is 2 or more, two or more of R.sub.504(s) may be identical to or different from each other. In some embodiments, a501 to a504 may each independently be an integer from 0 to 8.

[0278] In the present disclosure, 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, R.sub.508b, and R.sub.901 to R.sub.904 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 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 may each be the same as described herein.

[0279] 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, R.sub.508b, and R.sub.901 to R.sub.904 in Formulae 1-1 to 1-5, 2, 3, 502, and 503 and ii) R.sub.10a may each independently be: [0280] 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; [0281] 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; [0282] 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.20alkyl group, a C.sub.1-C.sub.20alkoxy 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 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 [0283] 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 [0284] Q.sub.1 to Q.sub.3 and Q.sub.31 to Q.sub.33 may each independently be: [0285] 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 [0286] 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.

[0287] 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, R.sub.508b, and R.sub.901 to R.sub.904 in Formulae 1-1 to 1-5, 2, 3, 502, and 503, and ii) R.sub.10a may each independently be: [0288] 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; [0289] a group represented by one selected from among Formulae 9-1 to 9-19; [0290] a group represented by one selected from among Formulae 10-1 to 10-246; or [0291] 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 may each be the same as described herein):

##STR00048## ##STR00049## ##STR00050## ##STR00051## ##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056## ##STR00057## ##STR00058## ##STR00059## ##STR00060## ##STR00061##

[0292] 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, D represents deuterium, and TMS represents a trimethylsilyl group.

[0293] Unless defined otherwise, for example, R.sub.10a may be: [0294] deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; [0295] 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.1-C.sub.60 aryloxy group, a C.sub.1-C.sub.60 arylthio 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; [0296] 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, or a C.sub.6-C.sub.60 arylthio 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, 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 [0297] 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).

[0298] Unless defined otherwise, for example, 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; 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.

Examples of Compounds

[0299] In one or more embodiments, the first compound may be at least one selected from Compounds HT01 to HT09:

##STR00062##

[0300] In one or more embodiments, the second compound may be at least one selected from Compounds ET01 to ET12:

##STR00063## ##STR00064## ##STR00065##

[0301] In one or more embodiments, the transition metal-containing compound may be at least one selected from Compounds BD01 to BD16:

##STR00066## ##STR00067## ##STR00068##

[0302] In one or more embodiments, the delayed fluorescence compound may be at least one selected from Compounds DFD01 to DFD12:

##STR00069## ##STR00070## ##STR00071##

Description of FIG. 1

[0303] FIG. 1 is a schematic cross-sectional view of a light-emitting device 10 according to one or more embodiments of the present disclosure. The light-emitting device 10 may include a first electrode 110, an interlayer 130, and a second electrode 150.

[0304] Hereinafter, the structure of the light-emitting device 10 according to one or more embodiments and a method of manufacturing the light-emitting device 10 will be described in more detail with reference to FIG. 1.

First Electrode 110

[0305] In FIG. 1, in one or more embodiments, a substrate may be additionally provided and arranged under the first electrode 110 and/or on the second electrode 150. In one or more embodiments, as the substrate, a glass substrate or a plastic substrate may be utilized. 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.

[0306] 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.

[0307] The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. In one or more embodiments, 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, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (AlLi), calcium (Ca), magnesium-indium (MgIn), magnesium-silver (MgAg), or any combination thereof.

[0308] The first electrode 110 may have a single-layer structure including (e.g., consisting of) a single layer or a multi-layer structure including multiple layers. For example, in some embodiments, the first electrode 110 may have a three-layer structure of ITO/Ag/ITO.

Interlayer 130

[0309] The interlayer 130 may be on the first electrode 110. The interlayer 130 may include an emission layer.

[0310] In one or more embodiments, 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.

[0311] In one or more embodiments, 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.

[0312] 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 two neighboring emitting units. When the interlayer 130 includes the two or more emitting units and the charge generation layer, the light-emitting device 10 may be a tandem light-emitting device.

Hole Transport Region in Interlayer 130

[0313] 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) multiple materials that are different from each other, or iii) a multi-layer structure including multiple layers including multiple materials that are different from each other.

[0314] 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.

[0315] For example, in one or more embodiments, 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 constituent layers of each structure are stacked sequentially from the first electrode 110 in the stated order.

[0316] In one or more embodiments, the hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:

##STR00072##

[0317] In Formulae 201 and 202, [0318] 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, [0319] 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, [0320] xa1 to xa4 may each independently be an integer from 0 to 5, [0321] xa5 may be an integer from 1 to 10, [0322] 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, [0323] 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, etc.) unsubstituted or substituted with at least one R.sub.10a (e.g., see Compound HT16), [0324] 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 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 unsubstituted or substituted with at least one R.sub.10a, and [0325] na1 may be an integer from 1 to 4.

[0326] For example, in some embodiments, each of Formulae 201 and 202 may include at least one selected from groups represented by Formulae CY201 to CY217:

##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079##

[0327] In Formulae CY201 to CY217, R.sub.10b and R.sub.10c may each independently be the same as described with respect to R.sub.10a, ring CY.sub.201 to ring CY.sub.204 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.

[0328] In one or more embodiments, ring CY.sub.201 to ring CY.sub.204 in Formulae CY201 to CY217 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.

[0329] In one or more embodiments, each of Formulae 201 and 202 may include at least one selected from the groups represented by Formulae CY201 to CY203.

[0330] In one or more embodiments, Formula 201 may include at least one selected from the groups represented by Formulae CY201 to CY203 and at least one selected from the groups represented by Formulae CY204 to CY217.

[0331] In one or more embodiments, in Formula 201, xa1 may be 1, R.sub.201 may be one selected from the groups represented by Formulae CY201 to CY203, xa2 may be 0, and R.sub.202 may be one selected from the groups represented by Formulae CY204 to CY207.

[0332] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) any groups represented by Formulae CY201 to CY203.

[0333] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) any groups represented by Formulae CY201 to CY203, and may include at least one selected from the groups represented by Formulae CY204 to CY217.

[0334] In one or more embodiments, each of Formulae 201 and 202 may not include (e.g., may exclude) any groups represented by Formulae CY201 to CY217.

[0335] For example, in one or more embodiments, the hole transport region may include: at least one selected from Compounds HT1 to HT46; 4,4,4-[tris(3-methylphenyl)phenylamino] triphenylamine (m-MTDATA); 4,4,4-tris(N,N-diphenylamino)triphenylamine (TDATA); 4,4,4-tris[N(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA); N,N-di(naphthalen-1-yl)-N,N-diphenyl-benzidine (NPB(NPD)); ?-NPB; N,N-bis(3-methylphenyl)-N,N-diphenyl-[1,1-biphenyl]-4,4-diamine (TPD); spiro-TPD; spiro-NPB; methylated NPB; 4,4-cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC); 4,4-bis[N,N-(3-tolyl)amino]-3,3-dimethylbiphenyl (HMTPD); 4,4,4-tris(N-carbazolyl)triphenylamine (TCTA); polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA); poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS); polyaniline/camphor sulfonic acid (PANI/CSA); polyaniline/poly(4-styrenesulfonate) (PANI/PSS); and/or any combination thereof:

##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090##

[0336] A thickness of the hole transport region may be in a range of about 50 ? 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, a thickness of the hole injection layer may be in a range of about 100 ? to about 9,000 ?, for example, about 100 ? to about 1,000 ?, and a thickness of the hole transport layer may be in a range of 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 these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

[0337] 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

[0338] In one or more embodiments, the hole transport region may further include, in addition to these aforementioned materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be substantially uniformly or non-uniformly dispersed in the hole transport region (e.g., in the form of a single layer including (e.g., consisting of) a charge-generation material).

[0339] The charge-generation material may be, for example, a p-dopant.

[0340] For example, in some embodiments, the p-dopant may have a LUMO energy level of ?3.5 eV or less.

[0341] In one or more embodiments, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or any combination thereof.

[0342] Non-limiting examples of the quinone derivative may be tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), and/or the like.

[0343] Non-limiting examples of the cyano group-containing compound may be dipyrazino[2,3-f: 2,3-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), a compound represented by Formula 221, and/or the like:

##STR00091##

[0344] In Formula 221, [0345] 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 [0346] at least one selected from among 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; Cl; 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.

[0347] In the compound including element EL1 and element EL2, element EL1 may be metal, metalloid, or any combination thereof, and element EL2 may be non-metal, metalloid, or any combination thereof.

[0348] Non-limiting examples of the metal may be: alkali metals (e.g., lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); alkaline earth metals (e.g., beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); transition metals (e.g., 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), etc.); post-transition metals (e.g., zinc (Zn), indium (In), tin (Sn), etc.); lanthanide metals (e.g., 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), etc.); and/or the like.

[0349] Non-limiting examples of the metalloid may be silicon (Si), antimony (Sb), tellurium (Te), and/or the like.

[0350] Non-limiting examples of the non-metal may be oxygen (O), a halogen (e.g., F, Cl, Br, I, etc.), and/or the like.

[0351] For example, in one or more embodiments, the compound including element EL1 and element EL2 may include metal oxides, metal halides (e.g., metal fluorides, metal chlorides, metal bromides, metal iodides, etc.), metalloid halides (e.g., metalloid fluorides, metalloid chlorides, metalloid bromides, metalloid iodides, etc.), metal tellurides, or any combination thereof.

[0352] Non-limiting examples of the metal oxide may be tungsten oxides (e.g., WO, W.sub.2O.sub.3, WO.sub.2, WO.sub.3, W.sub.2O.sub.5, etc.), vanadium oxides (e.g., VO, V.sub.2O.sub.3, VO.sub.2, V.sub.2O.sub.5, etc.), molybdenum oxides (e.g., MoO, Mo.sub.2O.sub.3, MoO.sub.2, MoO.sub.3, Mo.sub.2O.sub.5, etc.), rhenium oxides (e.g., ReO.sub.3, etc.), and/or the like.

[0353] Non-limiting examples of the metal halide may be alkali metal halides, alkaline earth metal halides, transition metal halides, post-transition metal halides, lanthanide metal halides, and/or the like.

[0354] Non-limiting examples of the alkali metal halide may be LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and/or the like.

[0355] Non-limiting examples of the alkaline earth metal halide may be 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, BaI.sub.2, and/or the like.

[0356] Non-limiting examples of the transition metal halide may be titanium halides (e.g., TiF.sub.4, TiCl.sub.4, TiBr.sub.4, TiI.sub.4, etc.), zirconium halides (e.g., ZrF.sub.4, ZrCl.sub.4, ZrBr.sub.4, ZrI.sub.4, etc.), hafnium halides (e.g., HfF.sub.4, HfCl.sub.4, HfBr.sub.4, HfI.sub.4, etc.), vanadium halides (e.g., VF.sub.3, VCl.sub.3, VBr.sub.3, VI.sub.3, etc.), niobium halides (e.g., NbF.sub.3, NbCl.sub.3, NbBr.sub.3, NbI.sub.3, etc.), tantalum halides (e.g., TaF.sub.3, TaCl.sub.3, TaBr.sub.3, TaI.sub.3, etc.), chromium halides (e.g., CrF.sub.3, CrO.sub.3, CrBr.sub.3, CrI.sub.3, etc.), molybdenum halides (e.g., MoF.sub.3, MoCl.sub.3, MoBr.sub.3, MoI.sub.3, etc.), tungsten halides (e.g., WF.sub.3, WCl.sub.3, WBr.sub.3, WI.sub.3, etc.), manganese halides (e.g., MnF.sub.2, MnCl.sub.2, MnBr.sub.2, MnI.sub.2, etc.), technetium halides (e.g., TcF.sub.2, TcCl.sub.2, TcBr.sub.2, TcI.sub.2, etc.), rhenium halides (e.g., ReF.sub.2, ReCl.sub.2, ReBr.sub.2, ReI.sub.2, etc.), ferrous halides (e.g., FeF.sub.2, FeCl.sub.2, FeBr.sub.2, FeI.sub.2, etc.), ruthenium halides (e.g., RuF.sub.2, RuCl.sub.2, RuBr.sub.2, RuI.sub.2, etc.), osmium halides (e.g., OsF.sub.2, OsCl.sub.2, OsBr.sub.2, OsI.sub.2, etc.), cobalt halides (e.g., CoF.sub.2, COCl.sub.2, CoBr.sub.2, CoI.sub.2, etc.), rhodium halides (e.g., RhF.sub.2, RhCl.sub.2, RhBr.sub.2, RhI.sub.2, etc.), iridium halides (e.g., IrF.sub.2, IrCl.sub.2, IrBr.sub.2, IrI.sub.2, etc.), nickel halides (e.g., NiF.sub.2, NiCl.sub.2, NiBr.sub.2, NiI.sub.2, etc.), palladium halides (e.g., PdF.sub.2, PdCl.sub.2, PdBr.sub.2, PdI.sub.2, etc.), platinum halides (e.g., PtF.sub.2, PtCl.sub.2, PtBr.sub.2, PtI.sub.2, etc.), cuprous halides (e.g., CuF, CuCl, CuBr, CuI, etc.), silver halides (e.g., AgF, AgCl, AgBr, AgI, etc.), gold halides (e.g., AuF, AuCl, AuBr, AuI, etc.), and/or the like.

[0357] Non-limiting examples of the post-transition metal halide may be zinc halides (e.g., ZnF.sub.2, ZnCl.sub.2, ZnBr.sub.2, ZnI.sub.2, etc.), indium halides (e.g., InI.sub.3, etc.), tin halides (e.g., SnI.sub.2, etc.), and/or the like.

[0358] Non-limiting examples of the lanthanide metal halide may be 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.

[0359] Non-limiting examples of the metalloid halide may be antimony halides (e.g., SbCl.sub.5, etc.) and/or the like.

[0360] Non-limiting examples of the metal telluride may be alkali metal tellurides (e.g., Li.sub.2Te, Na.sub.2Te, K.sub.2Te, Rb.sub.2Te, Cs.sub.2Te, etc.), alkaline earth metal tellurides (e.g., BeTe, MgTe, CaTe, SrTe, BaTe, etc.), transition metal tellurides (e.g., 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, etc.), post-transition metal tellurides (e.g., ZnTe, etc.), lanthanide metal tellurides (e.g., LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.), and/or the like.

Emission Layer in Interlayer 130

[0361] 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 selected from 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 (e.g., combined white light). In one or more embodiments, the emission layer may include two or more materials selected from 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 (e.g., combined white light).

[0362] 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 the dopant (or the emitter), in addition to the host and the dopant (or the emitter). When the emission layer includes the dopant (or the emitter) and the auxiliary dopant, the dopant (or the emitter) and the auxiliary dopant are different from each other.

[0363] An amount (weight) of the dopant (or the 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.

[0364] The transition metal-containing compound may be included in the emission layer. An amount (weight) of the transition metal-containing compound in the emission layer may be 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, based on 100 parts by weight of the emission layer.

[0365] A thickness of the emission layer may be in a range of about 100 ? to about 1,000 ?, for example, about 200 ? to about 600 ?. When the thickness of the emission layer is within these ranges, excellent or suitable luminescence characteristics may be obtained without a substantial increase in driving voltage.

Host

[0366] In one or more embodiments, the host may include a compound represented by Formula 301:

[Ar.sub.301].sub.xb11-[(L.sub.301).sub.xb1-R.sub.301].sub.xb21.Formula 301

[0367] In Formula 301, [0368] Ar.sub.301 and L.sub.301 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, [0369] xb11 may be 1, 2, or 3, [0370] xb1 may be an integer from 0 to 5, [0371] 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 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, 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), [0372] xb21 may be an integer from 1 to 5, and [0373] Q.sub.301 to Q.sub.303 may each be the same as described with respect to Q.sub.1.

[0374] For example, in some embodiments, when xb11 in Formula 301 is 2 or more, two or more of Ar.sub.301(s) may be linked to each other via a single bond.

[0375] 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:

##STR00092##

[0376] In Formulae 301-1 and 301-2, [0377] 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, [0378] 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), [0379] xb22 and xb23 may each independently be 0, 1, or 2, [0380] L.sub.301, xb1, and R.sub.301 may each be the same as described herein, [0381] L.sub.302 to L.sub.304 may each independently be the same as described with respect to L.sub.301, [0382] xb2 to xb4 may each independently be the same as described with respect to xb1, and [0383] R.sub.302 to R.sub.305 and R.sub.311 to R.sub.314 may each be the same as described with respect to R.sub.301.

[0384] 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 (e.g., Compound H55), a Mg complex, a Zn complex, or any combination thereof.

[0385] In one or more embodiments, the host may include: at least one selected from 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:

##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120## ##STR00121##

[0386] In one or more embodiments, the host may include a silicon-containing compound, a phosphine oxide-containing compound, or any combination thereof.

[0387] The host may have one or more suitable modifications. For example, the host may include only one kind or type of compound, or may include two or more kinds or types of different compounds.

Phosphorescent Dopant

[0388] The phosphorescent dopant may include at least one transition metal as a central metal.

[0389] 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.

[0390] In one or more embodiments, the phosphorescent dopant may be electrically neutral.

[0391] For example, in some embodiments, the phosphorescent dopant may include an organometallic compound represented by Formula 401:

##STR00122##

[0392] In Formulae 401 and 402, [0393] M may be a transition metal (e.g., iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium (Tm)), [0394] L.sub.401 may be a ligand represented by Formula 402, and xc1 is 1, 2, or 3, wherein, when xc1 is 2 or more, two or more of L.sub.401 (s) may be identical to or different from each other, [0395] L.sub.402 may be an organic ligand, and xc2 may be 0, 1, 2, 3, or 4, wherein, when xc2 is 2 or more, two or more of L.sub.402(s) may be identical to or different from each other, [0396] X.sub.401 and X.sub.402 may each independently be N or C, [0397] 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, [0398] 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(Q.sub.411)-*, [0399] X.sub.403 and X.sub.404 may each independently be a chemical bond (e.g., 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), [0400] Q.sub.411 to Q.sub.414 may each be the same as described with respect to Q.sub.1, [0401] 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), [0402] Q.sub.401 to Q.sub.403 may each be the same as described with respect to Q.sub.1, [0403] xc11 and xc12 may each independently be an integer from 0 to 10, and [0404] * and * in Formula 402 each indicate a binding site to M in Formula 401.

[0405] For example, in some embodiments, in Formula 402, i) X.sub.401 may be nitrogen and X.sub.402 may be carbon, or ii) each of X.sub.401 and X.sub.402 may be nitrogen.

[0406] In one or more embodiments, when xc1 in Formula 401 is 2 or more, two of ring A.sub.401 (s) among two or more of L.sub.401 (s) may be optionally linked to each other via T.sub.402, which is a linking group, and/or two of ring A.sub.402(s) among two or more of L.sub.401 (s) may be optionally linked to each other via T.sub.403, which is a linking group (see Compounds PD1 to PD4 and PD7). T.sub.402 and T.sub.403 may each be the same as described with respect to T.sub.401.

[0407] In Formula 401, L.sub.402 may be an organic ligand. For example, L.sub.402 may include a halogen, a diketone group (e.g., an acetylacetonate group), a carboxylic acid group (e.g., a picolinate group), C(?O), an isonitrile group, CN group, a phosphorus group (e.g., a phosphine group, a phosphite group, etc.), or any combination thereof.

[0408] In one or more embodiments, the phosphorescent dopant may include, for example, at least one selected from Compounds PD1 to PD39, or any combination thereof:

##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127## ##STR00128## ##STR00129## ##STR00130## ##STR00131## ##STR00132##

Fluorescent Dopant

[0409] 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.

[0410] For example, in one or more embodiments, the fluorescent dopant and the auxiliary dopant may each independently include a compound represented by Formula 501:

##STR00133##

[0411] In Formula 501, [0412] 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, [0413] xd1 to xd3 may each independently be 0, 1, 2, or 3, and [0414] xd4 may be 1, 2, 3, 4, 5, or 6.

[0415] For example, in some embodiments, Ar.sub.501 in Formula 501 may be a condensed cyclic group (e.g., an anthracene group, a chrysene group, a pyrene group, etc.) in which three or more monocyclic groups are condensed with each other.

[0416] In one or more embodiments, xd4 in Formula 501 may be 2.

[0417] For example, in one or more embodiments, the fluorescent dopant and the auxiliary dopant may each include at least one selected from Compounds FD1 to FD37, 4,4-bis(2,2-diphenylvinyl)-1,1-biphenyl (DPVBi), 4,4-bis[4-(N,N-diphenylamino)styryl]biphenyl (DPAVBi), or any combination thereof:

##STR00134## ##STR00135## ##STR00136## ##STR00137## ##STR00138## ##STR00139## ##STR00140## ##STR00141##

[0418] In one or more embodiments, the fluorescent dopant and the auxiliary dopant may each independently include the fourth compound represented by Formula 502 or 503 as described herein.

[Delayed Fluorescence Material]

[0419] In one or more embodiments, the emission layer may include a delayed fluorescence material.

[0420] In the present disclosure, the delayed fluorescence material may be selected from compounds capable of emitting delayed fluorescence based on a delayed fluorescence emission mechanism.

[0421] 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.

[0422] 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 about 0 eV or more and about 0.5 eV or less. 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 satisfied within the range above, up-conversion from the triplet state to the singlet state of the delayed fluorescence materials may effectively occur, and thus, the light-emitting device 10 may have improved luminescence efficiency.

[0423] For example, in one or more embodiments, the delayed fluorescence material may include i) a material including at least one electron donor (e.g., a ? electron-rich C.sub.3-C.sub.60 cyclic group, such as a carbazole group, etc.) and at least one electron acceptor (e.g., a sulfoxide group, a cyano group, a ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 cyclic group, etc.), and/or ii) a material including a C.sub.8-C.sub.60 polycyclic group in which two or more cyclic groups are condensed while sharing boron (B).

[0424] Non-limiting examples of the delayed fluorescence material may include at least one selected from Compounds DF1 to DF14:

##STR00142## ##STR00143## ##STR00144## ##STR00145##

Quantum Dot

[0425] In one or more embodiments, the emission layer may include a quantum dot.

[0426] The term quantum dot as utilized 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.

[0427] 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 dot, dots, or 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.

[0428] 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.

[0429] The wet chemical process is a method including mixing a precursor material of a quantum dot with an organic solvent and then growing quantum dot particle crystals. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal so that the growth of quantum dot particles 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).

[0430] The quantum dot may include: 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; a Group IV element or compound; or any combination thereof.

[0431] Non-limiting examples of the Group II-VI semiconductor compound may be: a binary compound, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and/or the like; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and/or the like; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and/or the like; or any combination thereof.

[0432] Non-limiting examples of the Group III-V semiconductor compound may be: 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, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and/or the like; or any combination thereof. In some embodiments, the Group III-V semiconductor compound may further include a Group II element. Non-limiting examples of the Group III-V semiconductor compound further including the Group II element may be InZnP, InGaZnP, InAlZnP, and/or the like.

[0433] Non-limiting examples of the Group III-VI semiconductor compound may be: 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, InTe, and/or the like; a ternary compound, such as InGaS.sub.3, InGaSe.sub.3, and/or the like; or any combination thereof.

[0434] Non-limiting examples of the Group I-III-VI semiconductor compound may be: 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.

[0435] Non-limiting examples of the Group IV-VI semiconductor compound may be: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, and/or the like; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and/or the like; a quaternary compound, such as SnPbSSe, SnPbSeTe, SnPbSTe, and/or the like; or any combination thereof.

[0436] Non-limiting examples of the Group IV element or compound may be: a single element compound, such as Si, Ge, and/or the like; a binary compound, such as SiC, SiGe, and/or the like; or any combination thereof.

[0437] 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 non-substantially uniform concentration in a particle.

[0438] In some embodiments, the quantum dot may have a single structure in which the concentration of each element in the quantum dot is substantially uniform, or may have a core-shell dual structure. For example, a material included in the core and a material included in the shell may be different from each other.

[0439] The shell of the quantum dot may act as a protective layer which prevents chemical denaturation of the core to maintain semiconductor characteristics, and/or as a charging layer which imparts electrophoretic characteristics to the quantum dot. The shell may be single-layered or multi-layered. 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.

[0440] Non-limiting examples of the shell of the quantum dot may be an oxide of metal, metalloid, or non-metal, a semiconductor compound, or a combination thereof. Non-limiting examples of the oxide of metal, metalloid, or non-metal may be: 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, NiO, and/or the like; a ternary compound, such as MgAl.sub.2O.sub.4, CoFe.sub.2O.sub.4, NiFe.sub.2O.sub.4, CoMn.sub.2O.sub.4, and/or the like; or any combination thereof. Non-limiting examples of the semiconductor compound may be: 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; or any combination thereof. Non-limiting examples of the semiconductor compound suitable as a shell may be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.

[0441] The quantum dot may have a full width at half maximum (FWHM) of an emission spectrum of about 45 nm or less, about 40 nm or less, or for example, about 30 nm or less. When the FWHM of the emission spectrum of the quantum dot is within these ranges, the quantum dot may have improved color purity or improved color reproducibility. In some embodiments, because light emitted through the quantum dot is emitted in all directions, the wide viewing angle may be improved.

[0442] In some embodiments, the quantum dot may be in the form of a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, a nanoplate particle, and/or the like.

[0443] Because the energy band gap of the quantum dot may be adjusted by controlling the size of the quantum dot, light having one or more suitable wavelength bands may be obtained from a quantum dot emission layer. Accordingly, by utilizing 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 sizes of the quantum dots may be selected to enable the quantum dots to emit red light, green light, and/or blue light. In some embodiments, the quantum dots with suitable sizes may be configured to emit white light by combination of light of one or more suitable colors.

Electron Transport Region in Interlayer 130

[0444] 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 (e.g., consisting of) multiple materials that are different from each other, or iii) a multi-layered structure including multiple layers including multiple materials that are different from each other.

[0445] 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.

[0446] For example, in one or more embodiments, 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 constituent layers of each structure are sequentially stacked from the emission layer in the stated order.

[0447] The electron transport region (e.g., the buffer layer, the hole blocking layer, the electron control layer, or the 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.

[0448] For example, in one or more embodiments, the electron transport region may include a compound represented by Formula 601:

[Ar.sub.601].sub.xe11[(L.sub.601).sub.xe1-R.sub.601].sub.xe21.Formula 601

[0449] In Formula 601, [0450] 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, [0451] xe11 may be 1, 2, or 3, [0452] xe1 may be 0, 1, 2, 3, 4, or 5, [0453] R.sub.601 may 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, 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), [0454] Q.sub.601 to Q.sub.603 may each be the same as described with respect to Q.sub.1, [0455] xe21 may be 1, 2, 3, 4, or 5, and [0456] at least one selected from 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 heterocyclic group unsubstituted or substituted with at least one R.sub.10a.

[0457] In one or more embodiments, when xe11 in Formula 601 is 2 or more, two or more of Ar.sub.601(s) may be linked to each other via a single bond.

[0458] In one or more embodiments, Ar.sub.601 in Formula 601 may be a substituted or unsubstituted anthracene group.

[0459] In one or more embodiments, the electron transport region may include a compound represented by Formula 601-1:

##STR00146##

[0460] In Formula 601-1, [0461] 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 selected from among X.sub.614 to X.sub.616 may be N, [0462] L.sub.611 to L.sub.613 may each be the same as described with respect to L.sub.601, xe611 to xe613 may each be the same as described with respect to xe1, [0463] R.sub.611 to R.sub.613 may each be the same as described with respect to R.sub.601, and [0464] 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 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.

[0465] For example, in some embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

[0466] In one or more embodiments, the electron transport region may include: at least one selected from Compounds ET1 to ET45; 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP); 4,7-diphenyl-1,10-phenanthroline (Bphen); tris(8-hydroxyquinolinato)aluminum (Alq3); bis(2-methyl-8-quinolinolato-N1,O8)-(1,1-biphenyl-4-olato)aluminum (BAlq); 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ); 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ); and/or any combination thereof:

##STR00147## ##STR00148## ##STR00149## ##STR00150## ##STR00151## ##STR00152## ##STR00153## ##STR00154## ##STR00155## ##STR00156## ##STR00157## ##STR00158## ##STR00159## ##STR00160## ##STR00161##

[0467] A thickness of the electron transport region may be in a range of 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 thickness of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport layer are within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.

[0468] In one or more embodiments, the electron transport region (e.g., the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

[0469] 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 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, or any combination thereof.

[0470] For example, in some embodiments, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) or ET-D2:

##STR00162##

[0471] In one or more embodiments, 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.

[0472] 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 (e.g., consisting of) multiple layers that are different from each other, or iii) a multi-layered structure including multiple layers including multiple materials that are different from each other.

[0473] 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.

[0474] 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.

[0475] The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may be oxides, halides (e.g., fluorides, chlorides, bromides, or iodides), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, respectively, or any combination thereof.

[0476] The alkali metal-containing compound may include: one or more selected from among: alkali metal oxides, 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, RbI, and/or the like; and/or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, Ba.sub.xSr.sub.1-xO (wherein x is a real number satisfying 0<x<1), Ba.sub.xCa.sub.1-xO (wherein x is a real number satisfying 0<x<1), and/or the like. 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 tellurides. Non-limiting examples of the lanthanide metal telluride may be 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, Lu.sub.2Te.sub.3, and/or the like.

[0477] The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include i) one of metal ions of the alkali metal, one of metal ions of the alkaline earth metal, and one of metal ions of the rare earth metal, respectively, and ii) a ligand bonded to the metal ions (i.e., the respective metal ion), 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.

[0478] In one or more embodiments, 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 above. In one or more embodiments, the electron injection layer may further include an organic material (e.g., the compound represented by Formula 601).

[0479] In one or more embodiments, the electron injection layer may include (e.g., consist of) i) an alkali metal-containing compound (e.g., an alkali metal halide), or ii) a) an alkali metal-containing compound (e.g., an alkali metal halide), and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. For example, in some 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.

[0480] When the electron injection layer further includes an organic material, 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 may be substantially uniformly or non-uniformly dispersed in a matrix including the organic material.

[0481] A thickness of the electron injection layer may be in a range of about 1 ? to about 100 ?, and, for example, about 3 ? to about 90 ?. When the thickness of the electron injection layer is within these ranges, satisfactory or suitable electron injection characteristics may be obtained without a substantial increase in driving voltage.

Second Electrode 150

[0482] The second electrode 150 may be on the interlayer 130 having a structure as described above. 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 utilized.

[0483] 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 semi-transmissive electrode, or a reflective electrode.

[0484] The second electrode 150 may have a single-layer structure or a multi-layer structure including multiple layers.

Capping Layer

[0485] A first capping layer may be arranged outside (e.g., on) the first electrode 110, and/or a second capping layer may be arranged outside (e.g., on) the second electrode 150. In one or more embodiments, 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.

[0486] In some embodiments, 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 semi-transmissive electrode or a transmissive electrode, and the first capping layer. In some embodiments, 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 semi-transmissive electrode or a transmissive electrode, and the second capping layer.

[0487] 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, so that the luminescence efficiency of the light-emitting device 10 may be improved.

[0488] Each of the first capping layer and the second capping layer may include a material having a refractive index of 1.6 or more (e.g., at 589 nm).

[0489] 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.

[0490] At least one of the first capping layer or the second capping layer may (e.g., the first capping layer and 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 each 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 or the second capping layer may (e.g., the first capping layer and the second capping layer may each independently) include an amine group-containing compound.

[0491] In one or more embodiments, at least one of the first capping layer or the second capping layer may (e.g., the first capping layer and the second capping layer may each independently) include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.

[0492] In one or more embodiments, at least one of the first capping layer or the second capping layer may (e.g., the first capping layer and the second capping layer may each independently) include at least one selected from Compounds HT28 to HT33, at least one selected from Compounds CP1 to CP6, ?-NPB, and/or any combination thereof:

##STR00163##

Electronic Apparatus

[0493] The light-emitting device may be included in one or more suitable electronic apparatuses. For example, in one or more embodiments, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, and/or the like.

[0494] In one or more embodiments, the electronic apparatus (e.g., 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 travel direction of light emitted from the light-emitting device. For example, in some embodiments, light emitted from the light-emitting device may be blue light, green light, or white light (e.g., combined white light). Details on the light-emitting device may be the same as described herein. In some embodiments, the color conversion layer may include a quantum dot.

[0495] 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 subpixel areas, and the color conversion layer may include a plurality of color conversion areas respectively corresponding to the subpixel areas.

[0496] A pixel-defining film may be arranged among the subpixel areas to define each of the subpixel areas.

[0497] 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.

[0498] The plurality of color filter areas (or the plurality of color conversion areas) may include a first area configured to emit first color light, a second area configured to emit second color light, and/or a third area configured to emit third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. For example, 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. For example, in one or more embodiments, the plurality of color filter areas (or the plurality of color conversion areas) may include quantum dots. In some embodiments, the first area may include a red quantum dot to emit red light, the second area may include a green quantum dot to emit green light, and the third area may not include (e.g., may exclude) any quantum dots. Details on the quantum dot may be the same as described herein. The first area, the second area, and/or the third area may each further include a scatter.

[0499] For example, 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 first-first color light, the second area may be to absorb the first light to emit second-first color light, and the third area may be to absorb the first light to emit third-first color light. For example, the first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths. In some embodiments, the first light may be blue light, the first-first color light may be red light, the second-first color light may be green light, and the third-first color light may be blue light.

[0500] In one or more embodiments, the electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein one selected from the source electrode and the drain electrode may be electrically connected to the first electrode or the second electrode of the light-emitting device.

[0501] The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.

[0502] The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like.

[0503] In one or more embodiments, the electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be arranged between the color filter and/or the color conversion layer and the light-emitting device. The sealing 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 sealing portion may be a sealing 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 sealing portion is a thin-film encapsulation layer, the electronic apparatus may be flexible.

[0504] Various functional layers may be additionally arranged on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the utilization of the electronic apparatus. Non-limiting examples of the functional layers may include a touch screen layer, a polarizing layer, and/or the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer.

[0505] The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by utilizing biometric information of a living body (e.g., fingertips, pupils, etc.). The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.

[0506] The electronic apparatus may be applied to one or more of displays, light sources, lighting, personal computers (e.g., a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (e.g., 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 (e.g., meters for a vehicle, an aircraft, and a vessel), projectors, and/or the like.

Electronic Equipment

[0507] The light-emitting device may be included in one or more suitable electronic equipment.

[0508] For example, the electronic equipment including the light-emitting device may be at least one of 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 mobile phone, a tablet, a phablet, a PDA, a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro display, a 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, or a signboard.

[0509] Because the light-emitting device of the present disclosure has excellent or suitable luminescence efficiency and long lifespan, the electronic equipment including the light-emitting device may have characteristics such as high luminance, high resolution, and low power consumption.

Description of FIG. 2 and FIG. 3

[0510] FIG. 2 is a cross-sectional view of a light-emitting apparatus as an example of an electronic apparatus according to one or more embodiments of the present disclosure.

[0511] The light-emitting apparatus of FIG. 2 may include a substrate 100, a thin-film transistor (TFT), a light-emitting device, and an encapsulation portion 300 that seals the light-emitting device.

[0512] The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be 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.

[0513] The TFT may be 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.

[0514] 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.

[0515] A gate insulating film 230 for insulating the activation layer 220 from the gate electrode 240 may be on the activation layer 220, and the gate electrode 240 may be on the gate insulating film 230.

[0516] An interlayer insulating film 250 may be 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.

[0517] The source electrode 260 and the drain electrode 270 may be 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, respectively.

[0518] The TFT may be electrically connected to the 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. The light-emitting device may be provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.

[0519] The first electrode 110 may be 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.

[0520] A pixel defining layer 290 including an insulating material may be on the first electrode 110. The pixel defining layer 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 layer 290 may be a polyimide-based organic film or a polyacrylic-based organic film. In some embodiments, at least some layers of the interlayer 130 may extend beyond the upper portion of the pixel defining layer 290 to be arranged in the form of a common layer.

[0521] The second electrode 150 may be 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.

[0522] The encapsulation portion 300 may be on the second capping layer 170. The encapsulation portion 300 may be arranged on the light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiN.sub.x), silicon oxide (SiO.sub.x), 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 (e.g., polymethyl methacrylate, polyacrylic acid, etc.), an epoxy-based resin (e.g., aliphatic glycidyl ether (AGE), etc.), or any combination thereof; or any combination of the inorganic films and the organic films.

[0523] FIG. 3 is a cross-sectional view of a light-emitting apparatus as an example of an electronic apparatus according to one or more embodiments of the present disclosure.

[0524] 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, the light-emitting device included in the light-emitting apparatus of FIG. 3 may be a tandem light-emitting device.

Description of FIG. 4

[0525] FIG. 4 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 a device that displays a moving image or still image, a portable electronic equipment, such as a mobile phone, a smart phone, a tablet personal computer (PC), a mobile communication terminal, an electronic notebook, an electronic book, a portable multimedia player (PMP), a navigation, or a 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). The electronic equipment 1 may be such a product above 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 of the present disclosure are not limited thereto. For example, in one or more embodiments, the electronic equipment 1 may include a dashboard of a vehicle, a center information display (CID) on a center fascia or dashboard of a vehicle, a room mirror display replacing a side mirror of a vehicle, an entertainment display arranged for the rear seat of a vehicle or arranged on the back of the front seat thereof, a head-up display (HUD) installed at the front of a vehicle or projected on a front window glass, and/or a computer generated hologram augmented reality head up display (CGH AR HUD). FIG. 4 illustrates an embodiment in which the electronic equipment 1 is a smart phone for convenience of explanation.

[0526] The electronic equipment 1 may include a display area DA and a non-display area NDA outside the display area DA. A display device of the electronic equipment 1 may implement an image through an array of a plurality of pixels that are two-dimensionally arranged in the display area DA.

[0527] The non-display area NDA is an area that does not display an image, and may entirely 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 printing circuit board may be electrically connected, may be arranged.

[0528] In the electronic equipment 1, a length in the x-axis direction and a length in the y-axis direction may be different from each other. In some embodiments, as shown in FIG. 4, the length in the x-axis direction may be shorter 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 longer than the length in the y-axis direction.

Description of FIGS. 5 and 6A to 6C

[0529] FIG. 5 is a schematic view of an exterior of a vehicle 1000 as electronic equipment including a light-emitting device according to one or more embodiments. FIGS. 6A to 6C are each a schematic view of an interior of the vehicle 1000 according to one or more embodiments.

[0530] Referring to FIGS. 5, 6A, 6B, and 6C, the vehicle 1000 may refer to one or more suitable apparatuses for moving an object to be transported, such as a human, an object, or an animal, from a departure point to a destination point. The vehicle 1000 may include a vehicle traveling on a road or a track, a vessel moving over the sea or a river, an airplane flying in the sky utilizing the action of air, and/or the like.

[0531] In one or more embodiments, the vehicle 1000 may travel on a road or a track. The vehicle 1000 may move in a set or predetermined direction according to rotation of at least one wheel thereof. For example, 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, or a train running on a track.

[0532] The vehicle 1000 may include a body 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. The exterior of the body 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.

[0533] The vehicle 1000 may include a side window glass 1100, a front window glass 1200, a side mirror 1300, a cluster 1400, a center fascia 1500, a passenger seat dashboard 1600, and a display device 2.

[0534] 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.

[0535] The side window glass 1100 may be installed on a side of the vehicle 1000. In some 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 some embodiments, the side window glass 1100 may include a first side window glass 1110 and a second side window glass 1120. In some 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.

[0536] In one or more embodiments, the side window glasses 1100 may be spaced apart from each other in the x-direction or the ?x-direction. For example, in some embodiments, the first side window glass 1110 and the second side window glass 1120 may be spaced apart from each other in the x-direction or the ?x-direction. In other words, an imaginary straight line L connecting the side window glasses 1100 may extend in the x-direction or the ?x-direction. For example, in some 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.

[0537] The front window glass 1200 may be installed in the front of the vehicle 1000. The front window glass 1200 may be arranged between the side window glasses 1100 facing each other.

[0538] The side mirror 1300 may provide a rear view of the vehicle 1000. The side mirror 1300 may be installed on the exterior of the vehicle body. In some embodiments, a plurality of side mirrors 1300 may be provided. Any one of the plurality of side mirrors 1300 may be arranged outside the first side window glass 1110. The other one of the plurality of side mirrors 1300 may be arranged outside the second side window glass 1120.

[0539] The cluster 1400 may be arranged in front of the steering wheel. The cluster 1400 may include a tachometer, a speedometer, a coolant thermometer, a fuel gauge turn indicator, a high beam indicator, a warning light, a seat belt warning light, an odometer, a hodometer, an automatic shift selector indicator, a door open warning light, an engine oil warning light, and/or a low fuel warning light.

[0540] 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/or a heater of a seat are arranged. The center fascia 1500 may be arranged on one side of the cluster 1400.

[0541] A passenger seat dashboard 1600 may be spaced apart from the cluster 1400 with the center fascia 1500 arranged therebetween. In some 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 some 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.

[0542] In one or more embodiments, the display device 2 may include a display panel 3, and the display panel 3 may display an image. The display device 2 may be arranged inside the vehicle 1000. In some embodiments, the display device 2 may be arranged between the side window glasses 1100 facing each other. The display device 2 may be arranged on at least one of the cluster 1400, the center fascia 1500, or the passenger seat dashboard 1600.

[0543] The display device 2 may include an organic light-emitting display device, an inorganic light-emitting display device, a quantum dot display device, and/or the like. Hereinafter, as the display device 2 according to one or more embodiments of the disclosure, an organic light-emitting display device including the light-emitting device according to the disclosure will be described as an example, but one or more suitable types (kinds) of display devices as described above may be utilized in embodiments of the disclosure.

[0544] Referring to FIG. 6A, in one or more embodiments, the display device 2 may be arranged on the center fascia 1500. In some embodiments, the display device 2 may display navigation information. In some embodiments, the display device 2 may display audio, video, or information regarding vehicle settings.

[0545] Referring to FIG. 6B, in one or more embodiments, the display device 2 may be arranged on the cluster 1400. When the display device 2 is arranged on the cluster 1400, the cluster 1400 may display driving information and/or the like through the display device 2. For example, in some embodiments, the cluster 1400 may be implemented digitally. The digital cluster 1400 may display vehicle information and driving information as images. For example, a needle and a gauge of a tachometer and one or more suitable warning light icons may be displayed by a digital signal.

[0546] Referring to FIG. 6C, in one or more embodiments, the display device 2 may be arranged on the passenger seat dashboard 1600. The display device 2 may be embedded in the passenger seat dashboard 1600 or arranged on the passenger seat dashboard 1600. In some embodiments, the display device 2 arranged on the passenger seat dashboard 1600 seat 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 device 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

[0547] The layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region may each be formed in a certain region by utilizing 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.

[0548] When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are each 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.sup.?3 torr, and at a deposition speed in a range of about 0.01 ?/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

[0549] The term C.sub.3-C.sub.60 carbocyclic group as utilized herein refers to a cyclic group including (e.g., consisting of) carbon only as a ring-forming atom and having 3 to 60 carbon atoms, and the term C.sub.1-C.sub.60 heterocyclic group as utilized herein refers to a cyclic group that has 1 to 60 carbon atoms and further has, in addition to carbon, 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 including (e.g., consisting of) one (e.g., only one) ring or a polycyclic group in which two or more rings are condensed with each other. For example, the number of ring-forming atoms of the C.sub.1-C.sub.60 heterocyclic group may be from 3 to 61.

[0550] The term cyclic group as utilized 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.

[0551] The term ? electron-rich C.sub.3-C.sub.60 cyclic group as utilized 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 utilized herein refers to a heterocyclic group that has 1 to 60 carbon atoms and includes *N?* as a ring-forming moiety.

[0552] For example, [0553] the C.sub.3-C.sub.60 carbocyclic group may be i) Group T.sub.1 or ii) a condensed cyclic group in which two or more of Group T.sub.1 are condensed with each other (e.g., 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), [0554] the C.sub.1-C.sub.60 heterocyclic group may be i) Group T.sub.2, ii) a condensed cyclic group in which two or more of Group T.sub.2 are condensed with each other, or iii) a condensed cyclic group in which at least one Group T.sub.2 and at least one Group T.sub.1 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, etc.), [0555] the ? electron-rich C.sub.3-C.sub.60 cyclic group may be i) Group T.sub.1, ii) a condensed cyclic group in which two or more of Group T.sub.1 are condensed with each other, iii) Group T.sub.3, iv) a condensed cyclic group in which two or more of Group T.sub.3 are condensed with each other, or v) a condensed cyclic group in which at least one Group T.sub.3 and at least one Group T.sub.1 are condensed with each other (e.g., 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, etc.), [0556] the ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group may be i) Group T.sub.4, ii) a condensed cyclic group in which two or more of Group T.sub.4 are condensed with each other, iii) a condensed cyclic group in which at least one Group T.sub.4 and at least one Group T.sub.1 are condensed with each other, iv) a condensed cyclic group in which at least one Group T.sub.4 and at least one Group T.sub.3 are condensed with each other, or v) a condensed cyclic group in which at least one Group T.sub.4, at least one Group T.sub.1, and at least one Group T.sub.3 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, etc.), [0557] Group T.sub.1 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, [0558] Group T.sub.2 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, [0559] Group T.sub.3 may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and [0560] Group T.sub.4 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.

[0561] The term cyclic group, C.sub.3-C.sub.60 carbocyclic group, C.sub.1-C.sub.60 heterocyclic group, ? electron-rich C.sub.3-C.sub.60 cyclic group, or ? electron-deficient nitrogen-containing C.sub.1-C.sub.60 heterocyclic group as utilized herein may 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, etc.) according to the structure of a formula for which the corresponding term is utilized. For example, the benzene group may be a benzo group, a phenyl group, a phenylene group, and/or the like, which may be easily understood by one of ordinary skill in the art according to the structure of a formula including the benzene group.

[0562] Depending on context, in the present disclosure, a divalent group may refer or be a polyvalent group (e.g., trivalent, tetravalent, etc., and not just divalent) per, e.g., the structure of a formula in connection with which of the terms are utilized.

[0563] Non-limiting examples of the monovalent C.sub.3-C.sub.60 carbocyclic group and the monovalent C.sub.1-C.sub.60 heterocyclic group are a C.sub.3-C.sub.10 cycloalkyl group, a C.sub.1-C.sub.11 heterocycloalkyl group, a C.sub.3-C.sub.1 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. Non-limiting 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.1 cycloalkylene group, a C.sub.1-C.sub.11 heterocycloalkylene group, a C.sub.3-C.sub.1 cycloalkenylene group, a C.sub.1-C.sub.11 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 substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

[0564] The term C.sub.1-C.sub.60 alkyl group as utilized herein refers to a linear or branched aliphatic hydrocarbon monovalent group that has 1 to 60 carbon atoms, and non-limiting examples thereof are 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, a tert-decyl group, and/or the like. The term C.sub.1-C.sub.60 alkylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.1-C.sub.60 alkyl group.

[0565] The term C.sub.2-C.sub.60 alkenyl group as utilized herein refers to a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of a C.sub.2-C.sub.60 alkyl group, and non-limiting examples thereof are an ethenyl group, a propenyl group, a butenyl group, and/or the like. The term C.sub.2-C.sub.60 alkenylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.2-C.sub.60 alkenyl group.

[0566] The term C.sub.2-C.sub.60 alkynyl group as utilized herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of a C.sub.2-C.sub.60 alkyl group, and non-limiting examples thereof are an ethynyl group, a propynyl group, and/or the like. The term C.sub.2-C.sub.60 alkynylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.2-C.sub.60 alkynyl group.

[0567] The term C.sub.1-C.sub.60 alkoxy group as utilized herein refers to a monovalent group represented by OA.sub.101 (wherein A.sub.101 is a C.sub.1-C.sub.60 alkyl group), and non-limiting examples thereof are a methoxy group, an ethoxy group, an isopropyloxy group, and/or the like.

[0568] The term C.sub.3-C.sub.10 cycloalkyl group as utilized herein refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof are 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 utilized herein refers to a divalent group having substantially the same structure as the C.sub.3-C.sub.10 cycloalkyl group.

[0569] The term C.sub.1-C.sub.10 heterocycloalkyl group as utilized herein refers to a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and non-limiting examples thereof are a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, a tetrahydrothiophenyl group, and/or the like. The term C.sub.1-C.sub.10 heterocycloalkylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.1-C.sub.10 heterocycloalkyl group.

[0570] The term C.sub.3-C.sub.10 cycloalkenyl group as utilized herein refers to a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and non-limiting examples thereof are a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, and/or the like. The term C.sub.3-C.sub.10 cycloalkenylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.3-C.sub.10 cycloalkenyl group.

[0571] The term C.sub.1-C.sub.10 heterocycloalkenyl group as utilized herein refers to a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having at least one carbon-carbon double bond in the cyclic structure thereof. Non-limiting examples of the C.sub.1-C.sub.10 heterocycloalkenyl group are a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, a 2,3-dihydrothiophenyl group, and/or the like. The term C.sub.1-C.sub.1a heterocycloalkenylene group as utilized herein refers to a divalent group having substantially the same structure as the C.sub.1-C.sub.1a heterocycloalkenyl group.

[0572] The term C.sub.6-C.sub.60 aryl group as utilized herein refers to a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term C.sub.6-C.sub.6a arylene group as utilized herein refers to a divalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms. Non-limiting examples of the C.sub.6-C.sub.60 aryl group are 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, an ovalenyl group, and/or the like. When the C.sub.6-C.sub.60 aryl group and the C.sub.1-C.sub.60 arylene group each include two or more rings, the rings may be condensed with each other.

[0573] The term C.sub.1-C.sub.60 heteroaryl group as utilized herein refers to a monovalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. The term C.sub.1-C.sub.60 heteroarylene group as utilized herein refers to a divalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. Non-limiting examples of the C.sub.1-C.sub.60 heteroaryl group are 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, a naphthyridinyl group, and/or the like. 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 rings may be condensed with each other.

[0574] The term monovalent non-aromatic condensed polycyclic group as utilized herein refers to a monovalent group (e.g., having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure as a whole. Non-limiting examples of the monovalent non-aromatic condensed polycyclic group are an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, an indeno anthracenyl group, and/or the like. The term divalent non-aromatic condensed polycyclic group as utilized herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

[0575] The term monovalent non-aromatic condensed heteropolycyclic group as utilized herein refers to a monovalent group (e.g., having 1 to 60 carbon atoms) having two or more rings condensed to each other, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having non-aromaticity in its entire molecular structure as a whole. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group are a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphtho indolyl 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 indenocarbazolyl 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, a benzothienodibenzothiophenyl group, and/or the like. The term divalent non-aromatic condensed heteropolycyclic group as utilized herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

[0576] The term C.sub.6-C.sub.60 aryloxy group as utilized herein refers to OA.sub.102 (wherein A.sub.102 is a C.sub.6-C.sub.60 aryl group), and the term C.sub.6-C.sub.60 arylthio group as utilized herein refers to SA.sub.103 (wherein A.sub.103 is a C.sub.6-C.sub.60 aryl group).

[0577] The term C.sub.7-C.sub.60 arylalkyl group as utilized herein refers to -A.sub.104A.sub.105 (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 utilized 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).

[0578] The term R.sub.10a as utilized herein may be: [0579] deuterium, F, Cl, Br, I, a hydroxyl group, a cyano group, or a nitro group; [0580] 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; [0581] 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 [0582] 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).

[0583] In the present disclosure, 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; or 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.

[0584] The term heteroatom as utilized herein refers to any atom other than a carbon atom. Non-limiting examples of the heteroatom are O, S, N, P, Si, B, Ge, Se, and any combination thereof.

[0585] The term transition metal as utilized herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and/or the like.

[0586] Ph as utilized herein refers to a phenyl group, Me as utilized herein refers to a methyl group, Et as utilized herein refers to an ethyl group, tert-Bu or Bu.sup.t as utilized herein refers to a tert-butyl group, and OMe as utilized herein refers to a methoxy group.

[0587] The term biphenyl group as utilized herein refers to a phenyl group substituted with a phenyl group. In some embodiments, the biphenyl group may be a substituted phenyl group having a C.sub.6-C.sub.60 aryl group as a substituent.

[0588] The term terphenyl group as utilized herein refers to a phenyl group substituted with a biphenyl group. In some embodiments, the terphenyl group may be 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.

[0589] * and * as utilized herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.

[0590] 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 utilized instead of A utilized in describing Synthesis Examples refers to that an identical molar equivalent of B was utilized in place of A.

EXAMPLES

Evaluation Example 1

[0591] FIG. 7 shows a time-resolved PL graph at 25? C. of a mixture including Compounds HT08 and ET08 at a weight ratio of 1:1. Here, Graph (1), i.e., curve (1), is a graph of an embodiment in which Compound HT08 was substituted with deuterium (substitution rate: 100%), and Graph (2), i.e., curve (2), is a graph of an embodiment in which Compound HT08 was not substituted with deuterium (substitution rate: 0%).

[0592] The average decay time according to the multi-exponential decay function fitting of Graph (1) of FIG. 7 and the average decay time according to the multi-exponential decay function fitting of Graph (2) of FIG. 7 were each measured, and results thereof are shown in Table 1.

TABLE-US-00001 TABLE 1 Classification Average decay time (?s) Graph (1) 5 Graph (2) 4.5

[0593] As an anode, a glass substrate with 15 ?/cm.sup.2 (1,200 ?) ITO deposited thereon was cut to a size of 50 mm?50 mm?0.7 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. The resultant glass substrate was loaded onto a vacuum deposition apparatus.

[0594] 2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 ?, and NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 300 ?.

[0595] Compound DFD02 as a dopant, Compound BD13 as an auxiliary dopant, and a mixed host including deuterium-substituted Compound HT05 (substitution rate: 100%) and Compound ET08 at a weight ratio of 5:5 were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 ?, wherein the ratio of the dopant was 1% by weight, the ratio of the auxiliary dopant was 15% by weight, and the emission layer was a blue fluorescent emission layer. Then, Compound ET08 was vacuum-deposited thereon to form a hole blocking layer having a thickness of 50 ?. Subsequently, Alq3 was deposited on the emission layer to form an electron transport layer having a thickness of 300 ?, and then LiF, which is a halogenated alkali metal, was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 ? and Al was vacuum-deposited thereon to form a cathode having a thickness of 3,000 ?, to form a LiF/Al electrode, thereby completing the manufacture of an organic light-emitting device.

##STR00164##

Examples 2 to 4 and Comparative Examples 1 to 4

[0596] Organic light-emitting devices were each manufactured in substantially the same manner as in Example 1, except that, in forming an emission layer, deuterium-substituted Compound HT05 (substitution rate: 100%) was replaced by respective compounds shown in Table 2.

Evaluation Example 2

[0597] The efficiency (cd/A) and lifespan (LT95) of each of the organic light-emitting devices manufactured in Examples 1 to 4 and Comparative Examples 1 to 4 at 1,000 cd/m.sup.2 were measured by utilizing Keithley MU 236 and luminance meter PR650. Regarding the measured results, the ratio of each of the efficiency and lifespan values of Example 1 relative to that of Comparative Example 1, the ratio of each of the efficiency and lifespan values of Example 2 relative to that of Comparative Example 2, the ratio of each of the efficiency and lifespan values of Example 3 relative to that of Comparative Example 3, and the ratio of each of the efficiency and lifespan values of Example 4 relative to that of Comparative Example 4 are shown in Table 2. In Table 2, the lifespan (LT95) is a measure of the time (hr) taken until the luminance declines to 95% of the initial luminance.

TABLE-US-00002 TABLE 2 Transition Ratio metal- Delayed Ratio of of First Second containing fluorescence Luminescence Lifespan compound compound compound compound efficiency (LT95) Example 1 HT05 ET08 BD13 DFD02 106% 144% (deuterium substitution rate: 100%) Comparative HT05 ET08 BD13 DFD02 100% 100% Example 1 (deuterium substitution rate: 0%) Example 2 HT06 ET08 BD13 DFD02 109% 133% (deuterium substitution rate: 100%) Comparative HT06 ET08 BD13 DFD02 100% 100% Example 2 (deuterium substitution rate: 0%) Example 3 HT07 ET08 BD13 DFD02 104% 128% (deuterium substitution rate: 100%) Comparative HT07 ET08 BD13 DFD02 100% 100% Example 3 (deuterium substitution rate: 0%) Example 4 HT08 ET08 BD13 DFD02 110% 150% (deuterium substitution rate: 100%) Comparative HT08 ET08 BD13 DFD02 100% 100% Example 4 (deuterium substitution rate: 0%) [00165] HT05 [00166] HT06 [00167] HT07 [00168] HT08

[0598] From Table 2, it was confirmed that each of the organic light-emitting devices according to Examples 1 to 4 had superior luminescence efficiency and device lifespan to its corresponding comparative organic light-emitting devices according to Comparative Examples 1 to 4.

[0599] According to the one or more embodiments of the present disclosure, a light-emitting device having increased luminescence efficiency and lifespan and a high-quality electronic apparatus including the light-emitting device may be manufactured.

[0600] In the present disclosure, it will be understood that the terms comprise(s), include(s), or have/has specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0601] Throughout the present disclosure, when a component such as a layer, a film, a region, or a plate is mentioned to be placed on another component, it will be understood that it may be directly on another component or that another component may be interposed therebetween. In some embodiments, directly on may refer to that there are no additional layers, films, regions, plates, etc., between a layer, a film, a region, a plate, etc. and the other part. For example, directly on may refer to two layers or two members are disposed without utilizing an additional member such as an adhesive member therebetween.

[0602] In the present disclosure, although the terms first, second, etc., may be utilized herein to describe one or more elements, components, regions, and/or layers, these elements, components, regions, and/or layers should not be limited by these terms. These terms are only utilized to distinguish one component from another component.

[0603] As utilized herein, the singular forms a, an, one, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the use of may when describing embodiments of the present disclosure refers to one or more embodiments of the present disclosure.

[0604] As utilized herein, the terms substantially, about, or similar terms are used as terms of approximation 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. About as used herein, is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, about may mean within one or more standard deviations, or within ?30%, 20%, 10%, 5% of the stated value.

[0605] Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of 1.0 to 10.0 is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, 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. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

[0606] The light-emitting device, the light-emitting apparatus, the display device, the electronic apparatus, the electronic device, 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 various components of the device may be formed on one integrated circuit (IC) chip or on separate IC chips. Further, the various components of the device 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 various components of the device 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 various 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 various 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.

[0607] 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 other 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.