Acridine compound for use in an electronic device and display device

Abstract

The present invention relates to acridine compound of formula structure (I), and to an electron transport layer, which comprises at least one compound of formula (I), an semiconductor layer comprising at least one compound of formula (I) as well as to an electronic device comprising a semiconductor layer thereof. ##STR00001##

Claims

1. An acridine compound of formula (I), with a ring system K1 and K2: ##STR00067## wherein n is 0, 1 or 2; A.sup.1 and A.sup.2 are independently selected from H or aromatic cyclic ring of unsubstituted or substituted phenylene, and the substituents are selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy, and at least one aromatic cyclic ring of A.sup.1 and/or A.sup.2 are annelated with the ring system K2 or the ring system K1; A.sup.3 has the formula (Ia), having a ring system L1, or has the formula (Ib), having a ring system L2, or has the formula (Ic), or has the formula (Id), or has the formula (Ie), or has the formula (If): ##STR00068## R.sup.1, R.sup.2 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.24 aryl and C.sub.1 to C.sub.18 alkyl, and the substituents are independently selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; R.sup.3 is selected from unsubstituted or substituted C.sub.6 to C.sub.24 aryl, and the substituents are independently selected from H, C.sub.18 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, unsubstituted or substituted C.sub.6 to C.sub.24 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; A.sup.4 to A.sup.22 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.24 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; wherein at least one of A.sup.5 and/or A.sup.6 are annelated with the ring system L1; wherein at least one of A.sup.7 and/or A.sup.8 and/or A.sup.9 annelated with the ring system L2; wherein formulas (Ia) to (If) of A.sup.3 are connected at the position marked with “*” via a single bond; and wherein when A.sup.3 has the formula (Id)— (i) n is 1 or 2, (ii) R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H and unsubstituted C.sub.6 to C.sub.18 aryl, or (iii) n is 1 or 2, and R.sup.4, R.sup.5,R.sup.6 and R.sup.7 are independently selected from H and unsubstituted C.sub.6 to C.sub.18 aryl.

2. The acridine compound according to claim 1, wherein for formula (I): n is 0, 1 or 2; A.sup.1 and A.sup.2 are independently selected from H and or aromatic cyclic ring of unsubstituted or substituted phenylene, and the phenylene of A.sup.1 and/or A.sup.2 are annelated with the ring system K2 or the ring system K1, A.sup.3 has the formula selected from Ia, Ib, Ic, Id, Ie or If, wherein for formula (Ia): A.sup.4, A.sup.5 and A.sup.6 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Ib): A.sup.7, A.sup.8 and A.sup.9 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Ic): R.sup.1, R.sup.2 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl and C.sub.1 to C.sub.18 alkyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; R.sup.3 is selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Id), (Ie) and (If): R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, unsubstituted or substituted C.sub.6 to C.sub.18 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy, and A.sup.10, A.sup.11, A.sup.12 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.24 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; and wherein for the substituent Id: n=1 or 2.

3. The acridine compound according to claim 1, wherein for formula (I): R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, unsubstituted or substituted C.sub.6 to C.sub.18 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy, wherein for the substituents R.sup.4, R.sup.5, R.sup.6 and R.sup.7 pyridyl is excluded if n=0.

4. The acridine compound according to claim 1, wherein n is 0 or 1; A.sup.1 and A.sup.2 are independently selected from H and phenylene; A.sup.3 has the formula selected from (Ia) to (If); wherein for formula (Ia): A.sup.4, A.sup.5 and A.sup.6 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Ib): A.sup.7, A.sup.8 and A.sup.9 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Ic): R.sup.1, R.sup.2 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl and C.sub.1 to C.sub.18 alkyl; R.sup.3 is selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Id), (Ie) and (If): R.sup.4, R.sup.5,R.sup.6 and R.sup.7 are independently selected from H, unsubstituted C.sub.6 to C.sub.18 aryl; A.sup.10, A.sup.11 and A.sup.12 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl.

5. The acridine compound according claim 1, wherein the acridine compound is selected from formula (F1) to (F5): ##STR00069##

6. The acridine compound according to claim 1, wherein the acridine compound is selected from formula (D1) to (D16): ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074##

7. A semiconductor layer, wherein the semiconductor layer comprises or consists of at least one compound of formula (I) according to claim 1.

8. The semiconductor layer according to claim 7, wherein the semiconductor layer is an electron transport layer.

9. The semiconductor layer according to claim 7, wherein the semiconductor layer further comprises at least one alkali halide or alkali organic complex.

10. An electronic device comprising at least one semiconductor layer according to claim 7.

11. The electronic device according to claim 10, wherein the at least one semiconductor layer further comprises at least one alkali halide or alkali organic organic complex.

12. The electronic device according to claim 10, wherein the electronic device comprises at least one semiconductor layer that is a first electron transport layer.

13. The electronic device according to according to claim 10, further comprising at least one anode layer, at least one cathode layer and at least one emission layer.

14. The electronic device according to according to claim 10, wherein the electronic device is a light emitting device, a light emitting diode, thin film transistor, a battery or a photovoltaic cell.

15. The electronic device according to claim 10, wherein the electronic device is a display device.

16. The semiconductor layer according to claim 7, wherein for formula (I): n is 0, 1 or 2; A.sup.1 and A.sup.2 are independently selected from H and or aromatic cyclic ring of unsubstituted or substituted phenylene, and the phenylene of A.sup.1 and/or A.sup.2 are annelated with the ring system K2 or the ring system K1, A.sup.3 has the formula selected from Ia, Ib, Ic, Id, Ie or If, wherein for formula (Ia): A.sup.4, A.sup.5 and A.sup.6 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Ib): A.sup.7, A.sup.8 and A.sup.9 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Ic): R.sup.1, R.sup.2 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl and C.sub.1 to C.sub.18 alkyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; R.sup.3 is selected from unsubstituted or substituted C.sub.6 to C.sub.18 aryl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy; wherein for formula (Id), (Ie) and (If): R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, unsubstituted or substituted C.sub.6 to C.sub.18 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy, and A.sup.10, A.sup.11, A.sup.12 are independently selected from unsubstituted or substituted C.sub.6 to C.sub.24 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.18 alkyl and C.sub.1 to C.sub.18 alkoxy; and wherein for the substituent Id: n=1 or 2.

17. The semiconductor layer according to claim 7, wherein for formula (I): R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are independently selected from H, unsubstituted or substituted C.sub.6 to C.sub.18 aryl and unsubstituted or substituted pyridyl, and the substituents are independently selected from H, C.sub.1 to C.sub.12 alkyl and C.sub.1 to C.sub.12 alkoxy, wherein for the substituents R.sup.4, R.sup.5, R.sup.6 and R.sup.7 pyridyl is excluded if n=0.

18. The semiconductor layer according to claim 7, wherein n is 0 or 1; A.sup.1 and A.sup.2 are independently selected from H and phenylene; A.sup.3 has the formula selected from (Ia) to (If); wherein for formula (Ia): A.sup.4, A.sup.5 and A.sup.6 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Ib): A.sup.7, A.sup.8 and A.sup.9 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Ic): R.sup.1, R.sup.2 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl and C.sup.1 to C.sup.18 alkyl; R.sup.3 is selected from unsubstituted C.sub.6 to C.sub.18 aryl; wherein for formula (Id), (Ie) and (If): R.sup.4, R.sup.5,R.sup.6 and R.sup.7 are independently selected from H, unsubstituted C.sub.6 to C.sub.18 aryl; A.sup.10, A.sup.11, and A.sup.12 are independently selected from unsubstituted C.sub.6 to C.sub.18 aryl.

19. The semiconductor layer according to claim 7, wherein the acridine compound is selected from formula (F1) to (F5): ##STR00075##

20. The semiconductor layer according to claim 7, wherein the acridine compound is selected from formula (D1) to (D16): ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080##

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a cross-sectional view showing an organic light emitting diode according to an embodiment.

(2) FIG. 2 is a cross-sectional view specifically showing an organic layer of an organic light emitting diode according to an embodiment.

(3) FIGS. 3 and 4 are cross-sectional views specifically showing a part of an organic layer of an organic light emitting diode according to an embodiment.

(4) The compound for an organic optoelectronic device represented by formula I may be appropriate for an organic layer of an organic optoelectronic device, for example, a host or matrix material—also referred in the specification to as matrix compound—of an emission layer, an electron transport layer or an electron injection layer.

(5) It is noted that the electron transport layer as well as the electron injection layer does not emit visible light (essentially non-emissive).

(6) The organic optoelectronic device may realize a low driving voltage, high efficiency, high luminance and long life-span by including the organic layer including the compound for an organic optoelectronic device.

(7) Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

(8) FIGS. 1 to 4 are schematic cross-sectional views of organic light emitting diodes 100, 200, 300, and 400 according to an embodiment of the present invention. Hereinafter, referring to FIG. 1, a structure of an organic light emitting diode according to an embodiment of the present invention and a method of manufacturing the same are as follows. The organic light emitting diode 100 has a structure where a cathode 110, an organic layer 105 including an optional hole transport region; an emission layer 130 comprising a compound according to formula I; and an anode 150 that are sequentially stacked.

(9) A substrate may be further disposed under the cathode 110 or on the anode 150. The substrate may be a substrate that is used in a general organic light emitting diode and may be a glass substrate or a transparent plastic substrate with strong mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

(10) The anode 150 may be formed by depositing or sputtering an anode material on a substrate. The anode material may be selected from materials having a high work function that makes hole injection easy. The anode 150 may be a reflective electrode, a transflective electrode, or a transmissive electrode. The anode material may use indium tin oxide ITO), indium zinc oxide IZO), tin oxide (SnO.sub.2), zinc oxide (ZnO), and the like. Or, it may be a metal such as magnesium (Mg), aluminum (Al), aluminum-lithium (Al-LI, calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

(11) The anode 150 may have a monolayer or a multi-layer structure of two or more layers. The organic light emitting diodes 100, 200, 300, and 400 according to an embodiment of the present invention may include a hole transport region; an emission layer 120; and a first electron transport layer 34 comprising a compound according to formula I.

(12) For example, referring to FIG. 2, an organic light emitting diode according to an embodiment of the present invention is described. The organic light emitting diodes 100, 200, 300, and 400 according to an embodiment of the present invention may include further a hole auxiliary layer 140 between the anode 120 and the emission layer 130.

(13) Referring to FIG. 3, the hole transport region 105 may include at least two layered hole auxiliary layer, and in this case, a hole auxiliary layer contacting the emission layer is defined as a hole transport auxiliary layer 33 and a hole auxiliary layer contacting an anode is defined as a hole transport layer 31 as well as two electron transport layer of electron transport layer (second-ETL) 135 comprising a compound according to formula I/first electron transport layer 34 comprising a compound of formula I, which is selected different with the compound according to formula I of the second electron transport layer. The hole transport region may include at least one of a hole injection layer, a hole transport layer, an electron blocking layer, and a buffer layer.

(14) The hole transport region may include only hole injection layer or only hole transport layer. Or, the hole transport region may have a structure where a hole injection layer 37/hole transport layer 31 or hole injection layer 37/hole transport layer 31/electron blocking layer is sequentially stacked from the anode 120.

(15) For example, the hole injection layer 37 and the electron injection layer 36 are additionally included and as shown in FIG. 4, anode 120/hole injection layer 37/hole transport layer 31/hole transport auxiliary layer 33/emission layer 130/second electron transport layer (second-ETL) 135 comprising a compound according to formula I/first electron transport layer 34 comprising a compound of formula I, which is selected different from the compound according to formula I of the second electron transport layer/electron injection layer 37/anode 110 are sequentially stacked.

(16) In another example, the hole injection layer 37 and the electron injection layer 36 are additionally included and as shown in FIG. 4, anode 120/hole injection layer 37/hole transport layer 31/hole transport auxiliary layer 33/emission layer 130/second electron transport layer (second-ETL) 135 comprising a compound according to formula I/first electron transport layer 34 comprising a compound of formula I, which is selected different with the compound according to formula I of the second electron transport layer/electron injection layer 37/anode 110 are sequentially stacked.

(17) The hole injection layer 37 may improve interface properties between ITO as an anode and an organic material used for the hole transport layer 31, and is applied on a non-planarized ITO and thus may planarize the surface of the ITO. For example, the hole injection layer 37 may include a material having a median value, particularly desirable conductivity between a work function of ITO and HOMO of the hole transport layer 31, in order to adjust a difference a work function of ITO as an anode and HOMO of the hole transport layer 31.

(18) When the hole transport region includes a hole injection layer 37, the hole injection layer may be formed on the anode 150 by any of a variety of methods, for example, vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, or the like.

(19) When hole injection layer is formed using vacuum deposition, vacuum deposition conditions may vary depending on the material that is used to form the hole injection layer, and the desired structure and thermal properties of the hole injection layer to be formed and for example, vacuum deposition may be performed at a temperature of about 100° C. to about 500° C., a pressure of about 10.sup.−8 torr to about 10.sup.−3 torr, and a deposition rate of about 0.01 to about 100 Å/see, but the deposition conditions are not limited thereto.

(20) When the hole injection layer is formed using spin coating, the coating conditions may vary depending on the material that is used to form the hole injection layer, and the desired structure and thermal properties of the hole injection layer to be formed. For example, the coating rate may be in the range of about 2000 rpm to about 5000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be in a range of about 80° C. to about 200° C., but the coating conditions are not limited thereto.

(21) Conditions for forming the hole transport layer and the electron blocking layer may be defined based on the above-described formation conditions for the hole injection layer.

(22) A thickness of the hole transport region may be from about 100 Å to about 10000 Å, for example, about 100 Å to about 1000 Å. When the hole transport region includes the hole injection layer and the hole transport layer, a thickness of the hole injection layer may be from about 100 Å to about 10,000 Å, for example about 100 Å to about 1000 Å and a thickness of the hole transport layer may be from about 50 Å to about 2,000 Å, for example about 100 Å to about 1500 Å. When the thicknesses of the hole transport region, the HIL, and the HTL are within these ranges, satisfactory hole transport characteristics may be obtained without a substantial increase in driving voltage.

(23) The hole transport region may further include a charge-generating material to improve conductivity, in addition to the materials as described above. The charge-generating material may be homogeneously or non-homogeneously dispersed in the hole transport region. The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of a quinine derivative, a metal oxide, and a cyano group-containing compound, but is not limited thereto. Non-limiting examples of the p-dopant are quinone derivatives such as tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), and the like; metal oxides such as tungsten oxide, molybdenum oxide, and the like; and cyano-containing compounds such as compound HT-D1 below.

(24) ##STR00041##

(25) The hole transport region may further include a buffer layer.

(26) The buffer layer may compensate for an optical resonance distance of light according to a wavelength of the light emitted from the EML, and thus may increase efficiency.

(27) The emission layer (EML) may be formed on the hole transport region by using vacuum deposition, spin coating, casting, LB method, or the like. When the emission layer is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the hole injection layer, though the conditions for the deposition and coating may vary depending on the material that is used to form the emission layer. The emission layer may include a host and a dopant.

(28) For example, the composition comprising compound of formula I may be used as a light-emitting material for an organic optoelectronic device such as an OLED. Herein, the compound of formula I may be used as the emitter host (also named EML host), and may further include at least one dopant. The dopant may be a red, green, or blue dopant.

(29) Other compounds that can be used as the emitter host is an anthracene matrix compound represented by formula 400 below:

(30) ##STR00042##

(31) In formula 400, Ar.sub.111 and Ar.sub.112 may be each independently a substituted or unsubstituted C.sub.6-C.sub.60 arylene group; Ar.sub.113 to Ar.sub.116 may be each independently a substituted or unsubstituted C.sub.1-C.sub.10 alkyl group or a substituted or unsubstituted C.sub.6-C.sub.60 aryl group; and g, h, i, and j may be each independently an integer from 0 to 4.

(32) In some embodiments, Ar.sub.111 and Ar.sub.112 in formula 400 may be each independently one of a phenylene group, a naphthylene group, a phenanthrenylene group, or a pyrenylene group; or a phenylene group, a naphthylene group, a phenanthrenylene group, a fluorenyl group, or a pyrenylene group, each substituted with at least one of a phenyl group, a naphthyl group, or an anthryl group.

(33) In formula 400, g, h, i, and j may be each independently an integer of 0, 1, or 2.

(34) In formula 400, Ar.sub.113 to Ar.sub.116 may be each independently one of a C.sub.1-C.sub.10 alkyl group substituted with at least one of a phenyl group, a naphthyl group, or an anthryl group; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, or a fluorenyl group; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, or a fluorenyl group, each substituted with at least one of a deuterium atom, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, 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 phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, or a fluorenyl group

(35) ##STR00043##
or formulas 2 or 3

(36) ##STR00044##

(37) Wherein in the formulas 2 and 3, X is selected form an oxygen atom and a sulfur atom, but embodiments of the invention are not limited thereto.

(38) In the formula 2, any one of R.sub.11 to R.sub.14 is used for bonding to Ar.sub.111. R.sub.11 to R.sub.14 that are not used for bonding to Ar.sub.111 and R.sub.15 to R.sub.20 are the same as R.sub.1 to R.sub.8.

(39) In the formula 3, any one of R.sub.21 to R.sub.24 is used for bonding to Ar.sub.111. R.sub.21 to R.sub.24 that are not used for bonding to Ar.sub.111 and R.sub.25 to R.sub.30 are the same as R.sub.1 to R.sub.8.

(40) Preferably, the EML host comprises between one and three heteroatoms selected from the group consisting of N, O or S. More preferred the EML host comprises one heteroatom selected from S or O.

(41) Preferably, the dipole moment of the EML host is selected ≥0.2 Debye and ≤1.45 Debye, preferably ≥0.4 Debye and ≤1.2 Debye, also preferred ≥0.6 Debye and ≤1.1 Debye.

(42) The dipole moment is calculated using the optimized using the hybrid functional B3LYP with the 6-31G* basis set as implemented in the program package TURBOMOLE V6.5. If more than one conformation is viable, the conformation with the lowest total energy is selected to determine the dipole moment of the molecules. Using this method, 2-(10-phenyl-9-anthracenyl)-benzo[b]naphtho[2,3-d]furan (CAS 1627916-48-6) has a dipole moment of 0.88 Debye, 2-(6-(10-phenylanthracen-9-yl)naphthalen-2-yl)dibenzo[b,d]thiophene (CAS 1838604-62-8) of 0.89 Debye, 2-(6-(10-phenylanthracen-9-yl)naphthalen-2-yl)dibenzo[b,d]furan (CAS 1842354-89-5) of 0.69 Debye, 2-(7-(phenanthren-9-yl)tetraphen-12-yl)dibenzo[b,d]furan (CAS 1965338-95-7) of 0.64 Debye, 4-(4-(7-(naphthalen-1-yl)tetraphen-12-yl)phenyl) dibenzo[b,d] furan (CAS 1965338-96-8) of 1.01 Debye.

(43) The dopant is mixed in a small amount to cause light emission, and may be generally a material such as a metal complex that emits light by multiple excitation into a triplet or more. The dopant may be, for example an inorganic, organic, or organic/inorganic compound, and one or more kinds thereof may be used.

(44) The dopant may be a fluorescent dopant, for example ter-fluorene, the structures are shown below. 4.4′-bis(4-diphenyl amiostyryl)biphenyl (DPAVBI, 2,5,8,11-tetra-tert-butyl perylene (TBPe), and Compound 4 below are examples of fluorescent blue dopants.

(45) ##STR00045##

(46) The dopant may be a phosphorescent dopant, and examples of the phosphorescent dopant may be an organic metal compound including Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd, or a combination thereof. The phosphorescent dopant may be, for example a compound represented by formula Z, but is not limited thereto:
L.sub.2MX (Z).

(47) In formula Z, M is a metal, and L and X are the same or different, and are a ligand to form a complex compound with M.

(48) The M may be, for example Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd or a combination thereof, and the L and X may be, for example a bidendate ligand.

(49) A thickness of the emission layer may be about 100 Å to about 1000 Å, for example about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, the emission layer may have improved emission characteristics without a substantial increase in a driving voltage.

(50) Next, an electron transport region is disposed on the emission layer.

(51) The electron transport region may include at least one of a second electron transport layer, a first electron transport layer, and an electron injection layer.

(52) For example, the electron transport region may have a structure of a second electron transport layer/first electron transport layer/electron injection layer or first electron transport layer/electron injection layer, but is not limited thereto. For example, an organic light emitting diode according to an embodiment of the present invention includes at least two electron transport layers in the electron transport region, and in this case, an electron transport layer contacting the emission layer is defined as an electron transport layer (second-ETL) 135.

(53) The electron transport layer (second-ETL) may have a monolayer or multi-layer structure including two or more different materials.

(54) The electron transport region may include at least one compound represented by formula I. For example, the electron transport region may include an electron transport layer (second-ETL), and the electron transport layer (second-ETL) may include the compound for an organic optoelectronic device represented by formula I. More specifically, the electron transport layer (second-ETL) 135 may include the compound for an organic optoelectronic device represented by formula I.

(55) According to another aspect of the present invention, the electron transport layer (second-ETL) 135 consists of compound of formula I.

(56) The formation conditions of the electron transport layer (second-ETL) 135, electron transport layer (first-ETL) 34, and electron injection layer 36 of the electron transport region refers to the formation condition of the hole injection layer.

(57) When the electron transport region includes the electron transport layer (second-ETL) 135, the electron transport layer may include at least one of BCP, Bphen, and BAlq, but is not limited thereto.

(58) ##STR00046##

(59) The thickness of the electron transport layer may be from about 20 Å to about 1000 Å, for example about 30 Å to about 300 Å. When the thickness of the electron transport layer is within these ranges, the electron transport layer may have improved electron transport auxiliary ability without a substantial increase in driving voltage.

(60) According to another aspect of the present invention, the electron transport layer (first-ETL) 34 comprises a compound of formula I.

(61) According to another aspect of the present invention, the first electron transport layer 34 comprises a compound of formula I and further comprises an alkali halide and/or alkali organic complex.

(62) The first or second electron transport layer may include in addition at least one of the BCP, Bphen and the following Alq.sub.3, Balq, TAZ and NTAZ;

(63) ##STR00047##

(64) or, the electron transport layer may include at least one of the following compounds ET1 and ET2, but is not limited thereto:

(65) ##STR00048##

(66) A thickness of the electron transport layer may be about 100 Å to about 1000 Å, for example about 150 Å to about 500 Å. When the thickness of the electron transport layer is within these ranges, the electron transport layer may have satisfactory electron transporting ability without a substantial increase in driving voltage.

(67) The second electron transport layer 135 may further include an alkali metal halide and/or alkali organic complex, in addition to the above-described materials. Preferably, the second electron transport layer 135 comprises an alkali organic complex.

(68) Preferably the second electron transport layer is free of a metal, an alkali metal halide and/or alkali organic complex.

(69) The alkali organic complex may include a lithium (Li organic complex). The Li complex may include, for example, the following compound ET-D1 (lithium quinolate, LiQ) or ET-D2.

(70) ##STR00049##

(71) The alkali halide may be selected from the group consisting of LiF, LiCl, LiBr, LiI NaF, NaCl, NaBr, NaI, KF, KBr and CsF.

(72) In addition, the electron transport region may include an electron injection layer (EIL) 36 that may facilitate injection of electrons from the anode 110.

(73) The electron injection layer 36 is disposed on an electron transport layer and may play a role of facilitating an electron injection from a cathode and ultimately improving power efficiency and be formed by using any material used in a related art without a particular limit, for example, LiF, Liq, NaCl, CsF, Li.sub.2O, BaO, Yb and the like.

(74) The electron injection layer may include at least one selected from LiF, NaCl, CsF, Li.sub.2O, and BaO.

(75) A thickness of the EIL may be from about 1 Å to about 100 Å, or about 3 Å to about 90 Å. When the thickness of the electron injection layer is within these ranges, the electron injection layer may have satisfactory electron injection ability without a substantial increase in driving voltage.

(76) The anode 150 is disposed on the organic layer 105. A material for the anode 150 may be a metal, an alloy, or an electrically conductive compound that have a low work function, or a combination thereof. Specific examples of the material for the anode 150 may be lithium (LI, magnesium (Mg), aluminum (Al), aluminum-lithium (Al-LI, calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), etc. In order to manufacture a top-emission light-emitting device, the anode 150 may be formed as a transmissive electrode from, for example, indium tin oxide ITO) or indium zinc oxide IZO).

(77) According to another aspect of the invention, a method of manufacturing an organic electroluminescent device (400) is provided, wherein on an anode electrode the other layers of hole injection layer (37), hole transport layer (31), optional an electron blocking layer (33), an emission layer (130), first electron transport layer (first-ETL) (34), second electron transport layer (second-ETL) (135), electron injection layer (36), and a cathode (110), are deposited in that order; or the layers are deposited the other way around, starting with the cathode (110).

(78) Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples.

(79) In table 2 the comparative compound C-1 is shown, which is used in the comparative example.

(80) In table 3 the inventive compounds Inv-1, Inv-2 and Inv-3 according to formula I are shown, which are used in the examples 1 to 4.

(81) In table 4 prior art compounds are shown, which are used in the device examples.

(82) TABLE-US-00002 TABLE 2 Comparative compound C-1 used in the device example Compound name Molecular and IUPAC name Structure Reference C-1 7-(3-(anthracen-9-yl)phenyl)dibenzo[c,h]acridine 0 US20130200341A1

(83) TABLE-US-00003 TABLE 3 Inventive compounds Inv-1, Inv-2 and Inv-3 according to formula I used in the examples 1 to 4 Compound name Molecular and IUPAC name Structure Inv-1 Inv-2 Inv-3

(84) TABLE-US-00004 TABLE 4 Prior art compounds used in the examples Compound name Molecular and IUPAC name Structure Reference ETM-1 W02016171358 ETM-2 US2016276596 HTM-1 US2016322581 HTM-2 JP2014096418 A2 DP-1 US2008265216 Host-1 US2015325800 Emitter Dopant NUBD370 from Sun Fine Chem (SFC), Korea 0 KR20110015213
General Synthesis of Compounds of Formula (I):

(85) Compounds of formula (I), for example Inv-1, Inv-2 and Inv-3, were synthesized by the same coupling reaction. The detailed description is given exemplary for compound Inv-1: Synthesis of 7-(3′-(9-phenyl-9H-fluoren-9-yl)-[1,1′-biphenyl]-3-yl)dibenzo[c,h]acridine

(86) ##STR00061##

(87) A 250-mL-Schenk flask was flushed with nitrogen. In the counterflow of nitrogen, the flask was charged with 7-(3-bromophenyl)dibenzo[c,h]acridine CAS-1352166-95-0 (6.0 g, 13.8 mmol), 4,4,5,5-tetramethyl-2-(3-(9-phenyl-9H-fluoren-9-yl)phenyl)-1,3,2-dioxaborolane CAS-1260032-45-8 (6.73 g, 15.2 mmol), and Pd(dppf)Cl.sub.2 (0.20 g, 0.28 mmol). In parallel, an aq. 2 M K.sub.2CO.sub.3 solution (3.80 g K.sub.2CO.sub.3, 128.0 mmol in 14 mL H.sub.2O) was deaerated by purging with nitrogen for 25 min. In the counterflow of nitrogen, deaerated toluene (85 mL) and the deaerated K.sub.2CO.sub.3 solution were added to the 250-mL-Schenk flask and the reaction mixture was heated to 100° C. (bath temperature) under a nitrogen atmosphere while stirring. The deep brown suspension showed largely dissolution at reflux temperature. After 22 h, TLC (silica, n-hexane/DCM, 1:1) and HPLC (MSt5186-a, 96.63% product) showed quantitative conversion (R.sub.t(7-(3-bromophenyl)dibenzo [c,h]-acridine)=8.4 min).

(88) After a total reaction time of 23 h, the reaction mixture was cooled down to room temperature and the precipitate was isolated by suction filtration over a sintered glass filter and washed with toluene (2×4 mL) and n-hexane (3×6 mL). The combined filtrates were concentrated to approx. 20 mL using a rotary evaporator and the resulting suspension was stirred for 30 min. at room temperature. The precipitate was isolated by suction filtration over a sintered glass filter and washed with n-hexane (4×6 mL).

(89) After the first filtration step, the yield of the crude product (about 8.8 g, about 92%) was surprisingly low (should be well above 100%), therefore a second crop (2.3 g) was isolated as described above. This can be circumvented by reducing the initial amount of toluene to about 11.8 mL/g 7-(3-bromophenyl)dibenzo[c,h] acridine.

(90) The combined solids (about 11.1 g) were suspended in dichloromethane (about 50 mL) and filtered over a pad of dry Florisil (diameter: 6 cm, height: 4 cm, covered with a filter paper) via suction filtration. Additional dichloromethane (about 650 mL) was used to rinse the product quantitatively. Both filtrates were combined. The combined filtrates were concentrated to an approx. volume of about 150 mL using a rotary evaporator. n-Hexane (about 25 mL) was added and the solvent volume was further reduced to about 50 mL using a rotary evaporator. The obtained suspension was stirred overnight. The solid was collected by suction filtration over a sintered glass filter and washed with n-hexane (3×about 30 mL). After drying at about 40° C. under vacuum (about 5 mbar), about 8.22 g (about 88%) of a pale yellow solid were obtained (MSt5186-b, about 99.49%). In order to improve the purity, the solid was dissolved in hot dichloromethane (about 150 mL) and the solution was concentrated to about 100 mL using a rotary evaporator. MTBE (about 70 mL) was added and the solvents were further evaporated using a rotary evaporator to a residual volume of about 50 mL. The obtained suspension was stirred for about 2 h at room temperature. The solid was collected by suction filtration over a sintered glass filter and washed with MTBE (2×about 5 mL). The solid was dried at about 120° C. in vacuo using an oil pump, to afford about 7.5 g (about 11.2 mmol, about 81%) of a pale yellow solid with a purity of about 99.81% according to HPLC (MSt5186-c).

(91) General Procedure for Fabrication of OLEDs

(92) For top emission devices, Examples 1 to 4 and comparative example 1, a glass substrate was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaned with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and cleaned again with UV ozone for 30 minutes. 100 nm Ag were deposited as anode on the glass at a pressure of 10.sup.−5 to 10.sup.−7 mbar.

(93) OLEDs were prepared to demonstrate the technical benefit utilizing the compounds of formula 1 in an organic electronic device. Table 5 shows the performance parameters of the OLED comprising inventive compounds of formula 1 and the metal complex additive LiQ in a weight ratio of 1:1 in a mixed materials electron transport layer.

(94) In OLED device example 1 an additional undoped electron transport layer was used as a hole-blocking layer.

(95) The layer stack is described by the following text string where the slashes stand for the interface between two adjacent layers: Ag (100 nm)/HTM-1:DP-1 [8 wt %] (10 nm)/HTM-1 (118 nm)/HTM-2 (5 nm)/Host-1:emitter dopant-1 [3 wt %] (20 nm)/ETM-1 (0-5 nm)/Inv1:LiQ or Inv-2:LiQ or Inv-3:LiQ [50 wt %] (31-36 nm)/Yb (2 nm)/Ag (11 nm).

(96) The electron transport layer (second-ETL) 135, if present, is formed with a thickness of 5 nm by depositing ETM-1 on the emission layer 130 according to Example 1, Table 5.

(97) The first electron transport layer 34 is formed either directly on the emission layer 130 according to Comparative Example 1 and Examples 2 to 4 (Table 5), or on the second electron transport layer (second ETL) 135 according to Example 1. If the electron transport layer 34 is in direct contact with the emission layer 130, the thickness is 36 nm. If the electron transport layer 34 is deposited on top of the second electron transport layer (second ETL, second electron transport layer), the thickness is 31 nm.

(98) The electron transport layer comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ.

(99) Then the electron injection layer 36 is formed on top of the first electron transport layer 34 by deposing LiQ with a thickness of 1.5 nm or Yb with a thickness of 2 nm. The cathode was evaporated at ultra-high vacuum of 10.sup.−7 mbar. Therefore, a thermal single co-evaporation of one or several metals was performed with a rate of 0, 1 to 10 nm/s (0.01 to 1 Å/s) in order to generate a homogeneous Ag cathode with a thickness of 11 nm.

(100) A cap layer of Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine was formed on the cathode with a thickness of 60 nm in case of MgAg cathode and 75 nm in case of Ag cathode.

(101) The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.

(102) To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured under ambient conditions (20° C.). Current voltage measurements are performed using a Keithley 2400 sourcemeter, and recorded in V. At 10 mA/cm.sup.2 for top emission devices, a calibrated spectrometer CAS140 from Instrument Systems is used for measurement of CIE coordinates and brightness in Candela. Lifetime LT of the device is measured at ambient conditions (20° C.) and 10 mA/cm.sup.2, using a Keithley 2400 sourcemeter, and recorded in hours.

(103) The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.

(104) The light output in external efficiency EQE and power efficiency (1 m/W efficiency) are determined at 10 mA/cm.sup.2 for top emission devices.

(105) To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode.

(106) To determine the power efficiency in 1 m/W, in a first step the luminance in candela per square meter (cd/m2) is measured with an array spectrometer CAS140 CT from Instrument Systems which has been calibrated by Deutsche Akkreditierungsstelle (DAkkS). In a second step, the luminance is then multiplied by π and divided by the voltage and current density.

(107) In bottom emission devices, the emission is predominately Lambertian and quantified in percent external quantum efficiency (EQE) and power efficiency in 1 m/W.

(108) In top emission devices, the emission is forward directed, non-Lambertian and also highly dependent on the micro-cavity. Therefore, the external quantum efficiency (EQE) and power efficiency in 1 m/W will be higher compared to bottom emission devices.

(109) Top Emission Devices

(110) In comparative example 1 the OLED comprises a first electron transport layer only and is free of a second electron transport layer. The first electron transport layer (first-ETL) comprises an acridine compound C-1 and alkali organic complex LiQ. The formula of C-1 is

(111) ##STR00062##

(112) The glass transition temperature is 121° C. The operating voltage is about 3.20 V, the efficiency is about 7.0 cd/A and the lifetime is about <100 hours.

(113) In examples 1 and 2, the first electron transport layer (first-ETL) comprises a compound of formula I, namely Inv-1 and an alkali organic complex LiQ.

(114) According to example 1 the OLED device comprises in addition a second ETL consisting of compound ETM-1.

(115) Examples 2 to 4 are free of a second electron transport layer (second-ETL). The formula of Inv-1 is:

(116) ##STR00063##
The formula of ETM-1 is:

(117) ##STR00064##

(118) In example 3, the first electron transport layer (first-ETL) comprises a compound of formula I, namely Inv-2 and an alkali organic complex LiQ. Example 3 is free of a second electron transport layer (second-ETL).

(119) The formula of Inv-2 is:

(120) ##STR00065##

(121) In example 4, the first electron transport layer (first-ETL) comprises a compound of formula I, namely Inv-3 and an alkali organic complex LiQ. Example 4 is free of a second electron transport layer (second-ETL).

(122) The formula of Inv-3 is:

(123) ##STR00066##

(124) The operating voltage is about 3.42.

(125) In example 5, the first electron transport layer (first-ETL 34) comprises a mixture of the compound ETM-2 and 8-Hydroxyquinolinolato-lithium (LiQ) in a wt % ratio of 1:1. The second electron transport layer (second-ETL 135) comprises the compound Inv-3 of formula (I).

(126) The layer stack of example-5 is described by the following text string where the slashes stand for the interface between two adjacent layers and the layer thickness is given in brackets: Ag (100 nm)/HTM-1:DP-1 [8 wt %] (10 nm) HTM-1 (117 nm)/HTM-2 (5 nm)/Host-1:emitter dopant-1 [3 wt %] (20 nm)/Inv-3 (5 nm)/ETM-2:LiQ [50 wt %] (31 nm)/Yb (2 nm)/Ag (11 nm).

(127) Referring to Tables 5 and 6, the organic light emitting diodes according to Examples 1 to 4 exhibited improved luminance efficiency and/or life-span characteristics simultaneously compared with the organic light emitting diode according to Comparative Example 1. The efficiency is significantly improved for example 1 to 4 in the range of about 7.5 to about 7.8 cd/A and the lifetime is significantly improved in the range of about 150 to about 420 hours.

(128) Table 5 shows the physical data of the OLED device tested for examples 1 to 4 and Comparative example 1.

(129) TABLE-US-00005 TABLE 5 Voltage at C.sub.Eff at 10 OLED Second- CIE 10 mA/ mA/cm.sup.2 Device First-ETL ETL 1931 y cm.sup.2 [V] [cd/A] Comperative C-1:LiQ none 0,047 3,2  7,0 Example 1 Example I Inv-1:LiQ ETM-1 0,047 3,55 7,8 Example 2 Inv-1:LiQ none 0,049 3,53 7,5 Example 3 Inv-2:LiQ none 0,049 3,34 7,7 Example 4 Inv-3:LiQ none 0,046 3,42 7,7 Example 5 ETM-2*.sup.1:LiQ Inv-3 0.045 3,19 8.6 .sup.*1 = ETM-2 is 2-([1,1′-bipheny1]-4-y1)-4-(9,9-dipheny1-9H-fluoren-4-y1)-6-pheny1-1,3,5-triazine (CAS 1801992-44-8).

(130) Table 6 shows the Tg and life span LT97 of the OLED device tested for examples 2 to 4 and comparative example 1.

(131) Lifetime LT of the device is measured at ambient conditions (20° C.) and 10 mA/cm.sup.2, using a Keithley 2400 sourcemeter, and recorded in hours. The brightness of the device is measured using a calibrated photo diode. The lifetime LT97 is defined as the time till the brightness of the device is reduced to 97% of its initial value.

(132) TABLE-US-00006 TABLE 6 compound name Tg [° C.] LT97 (h) C-1 about 121 <100 Inv-1 about 147 >150 Inv-2 about 159 >150 Inv-3 about 163 ≥420

(133) Table 6 clearly shows that the Tg of inventive compounds according to formula I is significant increased and the life time or life span is significant increased compared to the acridine compound of comparison example C-1.

(134) While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the aforementioned embodiments should be understood to be exemplary but not limiting the present invention in any way.