ORGANIC ELECTROLUMINESCENT COMPOUND AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME

Abstract

The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. By comprising the organic electroluminescent compound of the present disclosure, an organic electroluminescent device having improved driving voltage, luminous efficiency, and/or lifespan characteristics can be provided.

Claims

1. An organic electroluminescent compound represented by the following formula 1: ##STR00071## wherein Y.sub.1 to Y.sub.14 each independently represent N or CR.sub.1, in which if a plurality of R.sub.1's is present, each R.sub.1 may be the same or different; with the proviso that at least a pair of Y.sub.1 to Y.sub.14 wherein two of Y.sub.1 to Y.sub.14 are adjacent to each other are fused with the following formula 2 to form a ring: ##STR00072## Z represents NR.sub.2, O, S, CR.sub.3R.sub.4 or SiR.sub.5R.sub.6; X.sub.1 to X.sub.4 each independently represent N or CR.sub.7, in which if a plurality of R.sub.7's is present, each R.sub.7 may be the same or different; the dotted line represents a site fused with the adjacent two of Y.sub.1 to Y.sub.14 of formula 1; R.sub.2 represents ##STR00073## La represents a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (3- to 30-membered)heteroarylene, or a substituted or unsubstituted (C3-C30)cycloalkylene; Ar represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; R.sub.1 and R.sub.7 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or adjacent two R.sub.1's or adjacent two R.sub.7's may be linked to each other to form a ring; R.sub.3 to R.sub.6 each independently represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; or R.sub.3 and R.sub.4, or R.sub.5 and R.sub.6 may be linked to each other to form a ring; and a is an integer of 1 to 4, in which if a is 2 or more, each Ar may be the same or different.

2. The organic electroluminescent compound according to claim 1, wherein the substituents of the substituted (C1-C30)alkyl, the substituted (C6-C30)aryl(ene), the substituted (3- to 30-membered) heteroaryl(ene), the substituted (C3-C30)cycloalkyl(ene), the substituted (C1-C30)alkoxy, the substituted tri(C1-C30)alkylsilyl, the substituted di(C1-C30)alkyl(C6-C30)arylsilyl, the substituted (C1-C30)alkyldi(C6-C30)arylsilyl, the substituted tri(C6-C30)arylsilyl, the substituted mono- or di-(C1-C30)alkylamino, the substituted mono- or di-(C6-C30)arylamino, the substituted (C6-C30)aryl(3- to 30-membered)heteroarylamino, and the substituted (C1-C30)alkyl(C6-C30)arylamino in La, Ar, R.sub.1, and R.sub.3 to R.sub.7 each independently are at least one selected from the group consisting of deuterium; a halogen; a cyano; a carboxyl; a nitro; a hydroxyl; a (C1-C30)alkyl; a halo(C1-C30)alkyl; a (C2-C30)alkenyl; a (C2-C30)alkynyl; a (C1-C30)alkoxy; a (C1-C30)alkylthio; a (C3-C30)cycloalkyl; a (C3-C30)cycloalkenyl; a (3- to 7-membered)heterocycloalkyl; a (C6-C30)aryloxy; a (C6-C30)arylthio; a (5- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl; a (C6-C30)aryl unsubstituted or substituted with a (5- to 30-membered)heteroaryl; a tri(C1-C30)alkylsilyl; a tri(C6-C30)arylsilyl; a di(C1-C30)alkyl(C6-C30)arylsilyl; a (C1-C30)alkyldi(C6-C30)arylsilyl; an amino; a mono- or di-(C1-C30)alkylamino; a mono- or di-(C6-C30)arylamino; a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkylcarbonyl; a (C1-C30)alkoxycarbonyl; a (C6-C30)arylcarbonyl; a di(C6-C30)arylboronyl; a di(C1-C30)alkylboronyl; a (C1-C30)alkyl(C6-C30)arylboronyl; a (C6-C30)aryl(C1-C30)alkyl; and a (C1-C30)alkyl(C6-C30)aryl.

3. The organic electroluminescent compound according to claim 1, wherein formula 1 is represented by any one of the following formulas 3 and 4: ##STR00074## wherein Y.sub.1 to Y.sub.14, Z, and X.sub.1 to X.sub.4 are as defined in claim 1.

4. The organic electroluminescent compound according to claim 1, wherein Z represents NR.sub.2, O or S; La represents a single bond, a substituted or unsubstituted (C6-C15)arylene, or a substituted or unsubstituted (5- to 15-membered)heteroarylene; Ar represents a substituted or unsubstituted (C6-C15)aryl, a substituted or unsubstituted (5- to 15-membered)heteroaryl, a substituted or unsubstituted di(C6-C15)arylamino, or a substituted or unsubstituted (C6-C15)aryl(5- to 15-membered)heteroarylamino; R.sub.1 represents hydrogen; R.sub.7 represents hydrogen, a substituted or unsubstituted (C6-C15)aryl, a substituted or unsubstituted (5- to 15-membered)heteroaryl, a substituted or unsubstituted di(C6-C15)arylamino, or a substituted or unsubstituted (C6-C15)aryl(5- to 15-membered)heteroarylamino; and a is 1 or 2.

5. The organic electroluminescent compound according to claim 1, wherein Z represents NR.sub.2, O or S; La represents a single bond, an unsubstituted (C6-C15)arylene, or an unsubstituted (5- to 15-membered)heteroarylene; Ar represents an unsubstituted (C6-C15)aryl, a (5- to 15-membered)heteroaryl unsubstituted or substituted with a (C6-C15)aryl, a di(C6-C15)arylamino unsubstituted or substituted with a (C1-C6)alkyl, or an unsubstituted (C6-C15)aryl(5- to 15-membered)heteroarylamino; R.sub.1 represents hydrogen; R.sub.7 represents hydrogen, an unsubstituted (C6-C15)aryl, a (5- to 15-membered)heteroaryl unsubstituted or substituted with a (C6-C15)aryl, a di(C6-C15)arylamino unsubstituted or substituted with a (C1-C6)alkyl, or an unsubstituted (C6-C15)aryl(5- to 15-membered)heteroarylamino; and a is 1 or 2.

6. The organic electroluminescent compound according to claim 1, wherein the compound represented by formula 1 is selected from the group consisting of: ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102## ##STR00103## ##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115##

7. An organic electroluminescent material comprising the organic electroluminescent compound according to claim 1.

8. An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.

9. The organic electroluminescent device according to claim 8, wherein the organic electroluminescent compound is comprised in a light-emitting layer, a hole transport zone, or both of them.

Description

EXAMPLE 1: PREPARATION OF COMPOUND B-10

[0079] ##STR00049## ##STR00050##

[0080] Preparation of Compound 1-1

[0081] In a flask, 100 g of 1,8-dibromonaphthalene (349.7 mmol), 82 g of (2-chlorophenyl)boronic acid (524.6 mmol), 20.2 g of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh.sub.3).sub.4) (17.5 mmol), and 120.8 g of potassium carbonate (874.5 mmol) were dissolved in 1500 mL of tetrahydrofuran (THF) and 400 mL of distilled water, and the mixture was refluxed at 100 C. for 18 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. Thereafter, the resulting product was dried and separated by column chromatography to obtain 78 g of compound 1-1 (yield: 70%).

[0082] Preparation of Compound 1-2

[0083] In a flask, 10 g of compound 1-1 (31 mmol), 11.1 g of 2-(4,4,5,5-tetramethyl-1,3,2-dioxylboren-2-yl)-9H-carbazole (38 mmol), 1.8 g of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh.sub.3).sub.4) (1.55 mmol), and 10.9 g of potassium carbonate (79 mmol) were dissolved in 160 mL of tetrahydrofuran (THF) and 40 mL of distilled water, and the mixture was refluxed at 100 C. for 18 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. Thereafter, the resulting product was dried and separated by column chromatography to obtain 8 g of compound 1-2 (yield: 63%).

[0084] Preparation of Compound 1-3 and Compound of 1-4

[0085] In a flask, 26 g of compound 1-2 (64 mmol), 2.9 g of Pd(OAc).sub.2 (13 mmol), 7.1 g of ligand(tricyclohexylphosphonium tetrafluoroborate) (19 mmol) and 62.9 g of Cs.sub.2CO.sub.3 (193 mmol) were dissolved in 322 mL of dimethyl acetamide (DMA), and stirred for 6 hours under reflux. The mixture was cooled to room temperature, and distilled water was added thereto. An organic layer was extracted with ethyl acetate, and dried with magnesium sulfate. Thereafter, the resulting product was distilled under reduced pressure and separated by column chromatography to obtain 17 g of compound 1-3 (yield: 72%) and 3.2 g of compound 1-4 (yield: 14%).

[0086] Preparation of Compound B-10

[0087] 7.0 g of compound 1-3 (19 mmol), 4.6 g of 2-chloro-4-phenylquinazoline (19 mmol), 0.87 g of tris(dibenzylideneacetone)dipalladium(0) (0.95 mmol), 0.77 mL of tri-t-butylphosphine (1.9 mmol, 50% toluene solution), 3.6 g of sodium t-butoxide (38 mmol), and 190 mL of toluene were introduced into a flask and refluxed for 3 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain 5.8 g of yellow solid compound B-10 (yield: 53%, melting point: 310 C., glass transition temperature: 169 C.).

EXAMPLE 2: PREPARATION OF COMPOUND B-15

[0088] ##STR00051##

[0089] In a flask, 3.2 g of compound 1-4 (8.7 mmol), 2.5 g of 2-chloro-3-phenylquinoxaline (1.0 mmol), 5.7 g of cesium carbonate (17 mmol), and 0.53 g of 4-dimethylaminopyridine (DMAP) (4.4 mmol) were dissolved in 22 mL of dimethyl sulfoxide (DMSO), and the mixture was stirred at 100 C. for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and distilled water and methanol were added thereto. The solvent was removed using a filter, and the resulting solid was separated by column chromatography to obtain 2.5 g of compound B-15 (yield: 50%, melting point: 215 C., glass transition temperature: 170 C.).

EXAMPLE 3: PREPARATION OF COMPOUND A-9

[0090] ##STR00052##

[0091] 4.1 g of compound 1-3 (11 mmol), 5.3 g of N-(1,1-biphenyl-4-yl)-N-(4-bromophenyl)-[1,1-biphenyl]-4-amine (11 mmol), 0.51 g of tris(dibenzylideneacetone)dipalladium (0.55 mmol), 0.45 mL of tri-t-butylphosphine (1.1 mmol, 50% toluene solution), 2.1 g of sodium t-butoxide (22 mmol), and 111 mL of toluene were introduced into a flask and refluxed for 4 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain 3.9 g of white solid compound A-9 (yield: 46%, melting point: 216 C., glass transition temperature: 176 C.).

EXAMPLE 4: PREPARATION OF COMPOUND B-1

[0092] ##STR00053## ##STR00054##

[0093] Preparation of Compound 4-1

[0094] In a flask, 30 g of compound 1-1 (94.5 mmol), 15 g of phenylboronic acid (122.9 mmol), 5.5 g of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh.sub.3).sub.4) (4.73 mmol), and 32.7 g of potassium carbonate (236.3 mmol) were dissolved in 480 mL of tetrahydrofuran (THF) and 120 mL of distilled water, and the mixture was refluxed at 100 C. for 18 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. Thereafter, the resulting product was dried and separated by column chromatography to obtain 26 g of compound 4-1 (yield: 87%).

[0095] Preparation of Compound 4-2

[0096] In a flask, 26 g of compound 4-1 (82.6 mmol), 3.7 g of Pd(OAc).sub.2 (16.5 mmol), 9.1 g of ligand(tricyclohexylphosphonium tetrafluoroborate) (24.8 mmol), and 80.7 g of Cs.sub.2CO.sub.3 (247.8 mmol) were dissolved in 413 mL of dimethyl acetamide (DMA) and stirred for 3 hours under reflux. The mixture was cooled to room temperature, and distilled water was added thereto. The mixture was then extracted with methylene chloride (MC), and dried with magnesium sulfate. Thereafter, the resulting product was distilled under reduced pressure and separated by column chromatography to obtain 23 g of compound 4-2 (yield: 70%).

[0097] Preparation of Compound 4-3

[0098] In a flask, 7 g of compound 4-2 (25.1 mmol) was dissolved in 125 mL of dimethyl formamide (DMF), and 5.4 g of N-bromosuccinimide (NBS) (30.1 mmol) was added thereto. The mixture was stirred at room temperature for 4 hours, and methanol and distilled water were added thereto. The produced solid was filtered under reduced pressure and separated by column chromatography to obtain 5.6 g of compound 4-3 (yield: 62%).

[0099] Preparation of Compound 4-4

[0100] In a flask, 13 g of compound 4-3 (37 mmol), 8.0 g of 2-nitrophenylboronic acid (48 mmol), 2.1 g of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh.sub.3).sub.4) (1.85 mmol), and 12.8 g of potassium carbonate (92.5 mmol) were dissolved in 180 mL of tetrahydrofuran (THF) and 45 mL of distilled water, and the mixture was refluxed at 100 C. for 18 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. Thereafter, the resulting product was dried and separated by column chromatography to obtain 7.6 g of compound 4-4 (yield: 52%).

[0101] Preparation of Compound 4-5

[0102] 7.6 g of compound 4-4 (19 mmol), 12.5 g of triphenylphosphine (47.5 mmol), and 95 mL of 1,2-dichlorobenzene were introduced into a flask and stirred at 200 C. for 18 hours. After completion of the reaction, the solvent was removed by distillation under reduced pressure. Thereafter, the resulting product was separated by column chromatography to obtain 2.5 g of compound 4-5 (yield: 36%).

[0103] Preparation of Compound B-1

[0104] In a flask, 2.5 g of compound 4-5 (6.8 mmol), 2.3 g of compound 1-10 (6.8 mmol), 2.8 g of Cs.sub.2CO.sub.3 (20.4 mmol), and 0.42 g of 4-dimethylaminopyridine (DMAP) (3.4 mmol) were dissolved in 68 mL of dimethyl sulfoxide (DMSO), and the mixture was stirred at 100 C. for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and distilled water and methanol were added thereto. Thereafter, the solvent was removed using a filter, and the resulting solid was separated by column chromatography to obtain 2.2 g of compound B-1 (yield: 48%, melting point: 199 C., glass transition temperature: 177 C.).

EXAMPLE 5: PREPARATION OF COMPOUND B-6

[0105] ##STR00055##

[0106] In a flask, 6.0 g of compound 4-5 (16 mmol), 4.7 g of 2-chloro-3-phenylquinoxaline (20 mmol), 10.6 g of Cs.sub.2CO.sub.3 (33 mmol), and 1.0 g of 4-dimethylaminopyridine (DMAP) (8 mmol) were dissolved in 82 mL of dimethyl sulfoxide (DMSO), and the mixture was stirred at 100 C. for 6 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and distilled water and methanol were added thereto. The solvent was removed using a filter, and the resulting solid was separated by column chromatography to obtain 4.4 g of compound B-6 (yield: 47%, melting point: 271 C., glass transition temperature: 172 C.).

EXAMPLE 6: PREPARATION OF COMPOUND A-62

[0107] ##STR00056##

[0108] Preparation of Compound 6-1

[0109] In a flask, 35 g of compound 1-1 (110 mmol), 38.8 g of 3-(4,4,5,5-tetramethyl-1,3,2-dioxylboren-2-yl)-9H-carbazole (132 mmol), 6.5 g of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh.sub.3).sub.4) (5.5 mmol), and 38.1 g of potassium carbonate (275 mmol) were dissolved in 560 mL of tetrahydrofuran (THF) and 140 mL of distilled water, and the mixture was refluxed at 100 C. for 18 hours. After completion of the reaction, an organic layer was extracted with ethyl acetate, and the residual moisture was removed using magnesium sulfate. Thereafter, the resulting product was dried and separated by column chromatography to obtain 30 g of compound 6-1 (yield: 67%).

[0110] Preparation of Compound 6-2

[0111] In a flask, 30 g of compound 6-1 (74 mmol), 3.3 g of Pd(OAc).sub.2 (15 mmol), 8.2 g of ligand(tricyclohexylphosphonium tetrafluoroborate) (22 mmol), and 72.6 g of Cs.sub.2CO.sub.3 (223 mmol) were dissolved in 372 mL of dimethyl acetamide (DMA) and stirred for 6 hours under reflux. The mixture was cooled to room temperature, and distilled water was added thereto. An organic layer was then extracted with ethyl acetate and dried with magnesium sulfate. Thereafter, the resulting product was distilled under reduced pressure and separated by column chromatography to obtain 24 g of compound 6-2 (yield: 44%).

[0112] Preparation of Compound A-62

[0113] 5.0 g of compound 6-2 (14 mmol), 5.3 g of 4-bromo-N,N-diphenylaniline (16 mmol), 0.62 g of tris(dibenzylideneacetone)dipalladium(0) (0.68 mmol), 0.54 mL of tri-t-butylphosphine (1.4 mmol, 50% toluene solution), 2.6 g of sodium t-butoxide (28 mmol), and 136 mL of toluene were introduced into a flask and refluxed for 6 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain 2.4 g of white solid compound A-62 (yield: 29%, melting point: 188 C., glass transition temperature: 162 C.).

DEVICE EXAMPLES 1 TO 3: PRODUCTION OF AN OLED DEVICE USING THE COMPOUND ACCORDING TO THE PRESENT DISCLOSURE AS A HOST

[0114] An organic light-emitting diode (OLED) device was produced comprising the compound according to the present disclosure. A transparent electrode indium tin oxide (ITO) thin film (10 /sq) on a glass substrate for an OLED device (Geomatec, Japan) was subjected to an ultrasonic washing with acetone, ethanol, and distilled water, sequentially, and was then stored in isopropyl alcohol. Next, the ITO substrate was mounted on a substrate holder of a vacuum vapor depositing apparatus. Compound HI-1 was introduced into a cell of said vacuum vapor depositing apparatus, and then the pressure in the chamber of said apparatus was controlled to 10.sup.6 torr. Thereafter, an electric current was applied to the cell to evaporate the above-introduced material, thereby forming a first hole injection layer having a thickness of 80 nm on the ITO substrate. Compound HI-2 was then introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole injection layer having a thickness of 5 nm on the first hole injection layer. Compound HT-1 was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a first hole transport layer having a thickness of 10 nm on the second hole injection layer. Compound HT-2 was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole transport layer having a thickness of 60 nm on the first hole transport layer. After forming the hole injection layers and the hole transport layers, a light-emitting layer was then deposited as follows. The compound shown in Table 1 below was introduced into one cell of the vacuum vapor depositing apparatus as a host, and compound D-71 was introduced into another cell as a dopant. The two materials were evaporated at different rates and were deposited in a doping amount of 3 wt % based on the total amount of the host and dopant to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. Compound ET-1 and compound EI-1 were then introduced into two other cells, evaporated at the rate of 1:1, and deposited to form an electron transport layer having a thickness of 35 nm on the light-emitting layer. Next, after depositing compound EI-1 as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 80 nm was deposited by another vacuum vapor deposition apparatus on the electron injection layer. Thus, an OLED device was produced.

COMPARATIVE EXAMPLE 1: PRODUCTION OF AN OLED DEVICE USING A COMPARATIVE COMPOUND AS A HOST

[0115] An OLED device was produced in the same manner as in Device Example 1, except that compound A was used as the host of the light-emitting layer.

##STR00057##

TABLE-US-00001 TABLE 1 Host Driving Lifespan Material Voltage (V) Color (T95, hr) Comparative CBP 9.2 Red 0.25 Example 1 Device B-10 4.9 Red 3.6 Example 1 Device B-15 3.5 Red 4.6 Example 2 Device B-6 3.6 Red 2.6 Example 3

[0116] The organic electroluminescent device comprising the organic electroluminescent compound of the present disclosure as a host exhibited lower driving voltage and better lifespan characteristics than the organic electroluminescent device comprising the compound of Comparative Example 1.

DEVICE EXAMPLE 4: PRODUCTION OF AN OLED DEVICE USING THE COMPOUND ACCORDING TO THE PRESENT DISCLOSURE AS A SECOND HOLE TRANSPORT MATERIAL

[0117] An OLED device was produced comprising the compound according to the present disclosure. A transparent electrode indium tin oxide (ITO) thin film (10 /sq) on a glass substrate for an OLED device (Geomatec, Japan) was subjected to an ultrasonic washing with acetone and isopropyl alcohol, sequentially, and was then stored in isopropyl alcohol. Next, the ITO substrate was mounted on a substrate holder of a vacuum vapor depositing apparatus. Compound HI-1 was introduced into a cell of said vacuum vapor depositing apparatus, and then the pressure in the chamber of said apparatus was controlled to 10.sup.6 torr. Thereafter, an electric current was applied to the cell to evaporate the above-introduced material, thereby forming a first hole injection layer having a thickness of 90 nm on the ITO substrate. Compound HI-2 was then introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole injection layer having a thickness of 5 nm on the first hole injection layer. Compound HT-1 was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a first hole transport layer having a thickness of 10 nm on the second hole injection layer. The compound shown in Table 2 below as a second hole transport material (auxiliary material) was introduced into another cell of said vacuum vapor depositing apparatus, and was evaporated by applying an electric current to the cell, thereby forming a second hole transport layer having a thickness of 60 nm on the first hole transport layer. After forming the hole injection layers and the hole transport layers, a light-emitting layer was then deposited as follows. Compound H-1 was introduced into one cell of the vacuum vapor depositing apparatus as a host, and compound D-71 was introduced into another cell as a dopant. The two materials were evaporated at different rates and were deposited in a doping amount of 2 wt % based on the total amount of the host and dopant to form a light-emitting layer having a thickness of 40 nm on the second hole transport layer. Compound ET-1 and compound EI-1 were then introduced into two other cells, evaporated at the rate of 1:1, and deposited to form an electron transport layer having a thickness of 35 nm on the light-emitting layer. Next, after depositing compound EI-1 as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 1500 nm was deposited by another vacuum vapor deposition apparatus. Thus, an OLED device was produced.

[0118] The driving voltage, luminous efficiency, and CIE coordinates at a luminance of 1,000 nits, and the time taken for luminance to decrease from 100% to 98% at a constant current and at a luminance of 5,000 nits (lifespan; T98) of the produced OLED device are provided in Table 2 below.

COMPARATIVE EXAMPLE 2: PRODUCTION OF AN OLED DEVICE USING A COMPARATIVE COMPOUND AS A SECOND HOLE TRANSPORT MATERIAL

[0119] An OLED device was produced in the same manner as in Device Example 4, except that compound HT-1 was used as the second hole transport material.

[0120] The produced OLED device was evaluated in the same manner as in Device Example 4.

TABLE-US-00002 TABLE 2 Second Hole Transport Layer Driving Luminous Lifespan (Auxiliary Layer) Host Voltage (V) Efficiency (cd/A) CIE (x, y) (T98, hr) Device A-9 H-1 3.2 21.7 (0.670, 0.330) 83 Example 4 Comparative HT-1 3.2 11.4 (0.661, 0.336) 27 Example 2

[0121] The organic electroluminescent device comprising the organic electroluminescent compound of the present disclosure as a second hole transport material exhibited higher luminous efficiency and better lifespan characteristics than the organic electroluminescent device comprising the compound of Comparative Example 2.

TABLE-US-00003 TABLE 3 Organic electroluminescent materials used in the Device Examples and the Comparative Examples Hole Injection Layer/ Hole Transport Layer [00058] [00059] [00060] [00061] [00062] Light-Emitting Layer [00063] [00064] [00065] [00066] [00067] [00068] Electron Transport Layer/Electron Injection Layer [00069] [00070]