Organic Electronic Device and Display Device Comprising the Organic Electronic Device
20230057069 · 2023-02-23
Inventors
Cpc classification
H10K85/6572
ELECTRICITY
H10K85/6574
ELECTRICITY
H10K85/6576
ELECTRICITY
International classification
Abstract
The present invention relates to an organic material and to an electronic device comprising the organic material, particularly to an electroluminescent device, particularly to an organic light emitting diode (OLED), wherein the semiconducting material comprises a tetrasubstituted unsymmetric pyrazine.
Claims
1. An organic electronic device comprising an anode, a cathode, at least one photoactive layer and at least one organic semiconductor layer, wherein the at least one organic semiconductor layer is arranged between the at least one photoactive layer and the cathode; and wherein the at least one organic semiconductor layer comprises a C.sub.s-symmetric compound of Formula (1): ##STR00076## wherein R.sup.1-R.sup.4 are independently selected from a substituted or unsubstituted C.sub.6-C.sub.36 aryl, and a substituted or unsubstituted C.sub.3-C.sub.36 heteroaryl; wherein at least one of the R.sup.1-R.sup.4 is selected from a C.sub.3-C.sub.36 heteroaryl group or heteroarylene group which is directly attached to the pyrazine ring in formula 1 and at least three of R.sup.1-R.sup.4 are different to each other; wherein, if substituent(s) are present in R.sup.1, R.sup.2, R.sup.3, and R.sup.4, the substituent(s) are independently selected from the groups consisting of C.sub.6-C.sub.18 aryl, C.sub.3-C.sub.20 heteroaryl, D, F, CN, C.sub.1-C.sub.16 alkyl, C.sub.1-C.sub.16 alkoxy, PY(R).sub.2, OR, SR, (C═O)R, (C═O)N(R).sub.2, Si(R).sub.3, (S═O)R, and ##STR00077## whereby Y is O or S; and R is independently selected from C.sub.1-C.sub.20 linear alkyl, C.sub.1-C.sub.20 alkoxy, C.sub.1-C.sub.20 thioalkyl, C.sub.3-C.sub.20 branched alkyl, C.sub.3-C.sub.20 cyclic alkyl, C.sub.3-C.sub.20 branched alkoxy, C.sub.3-C.sub.20 cyclic alkoxy, C.sub.3-C.sub.20 branched thioalkyl, C.sub.3-C.sub.20 cyclic thioalkyl, C.sub.6-C.sub.20 aryl and C.sub.3-C.sub.20 heteroaryl; and wherein the following compounds 1-4 are excluded: ##STR00078##
2. The organic electronic device of claim 1, wherein the R.sup.1 to R.sup.4 that are not a substituted or unsubstituted C.sub.3-C.sub.36 heteroaryl or heteroarylene, which is directly attached to the pyrazine ring in formula (1) through a single bond are selected from substituted or unsubstituted C.sub.6-C.sub.20 aryl, and a substituted or unsubstituted C.sub.3-C.sub.18 heteroaryl.
3. The organic electronic device of claim 1, whereby the at least one of the R.sup.1 to R.sup.4 that is C.sub.3-C.sub.36 heteroaryl group or heteroarylene group which is directly attached to the pyrazine ring in formula (1) through a single bond is a substituted or unsubstituted C.sub.3-C.sub.18 heteroaryl or heteroarylene.
4. The organic electronic device of claim 1, whereby the compound has a dipole moment of ≥0.4 D.
5. The organic electronic device of claim 1, whereby one or two of the R.sup.1-R.sup.4 are phenyl or naphthenyl.
6. The organic electronic device of claim 1, whereby two of the R.sup.1-R.sup.4 are phenyl or naphthenyl and in ortho position to each other.
7. The organic electronic device of claim 1, whereby at least one of the R.sup.1 to R.sup.4 is selected from formula (2):
-L-(Ar).sub.n (2) whereby L is substituted or unsubstituted C.sub.6-C.sub.36 arylene; Ar is selected from a substituted or unsubstituted C.sub.6-C.sub.36 aryl, and a substituted or unsubstituted C.sub.3-C.sub.36 heteroaryl; n is 1 to 5; and two or more groups Ar may be identical to or different from each other.
8. The organic electronic device of claim 1, whereby L is chosen from one of the following moieties A1 to A16: ##STR00079## ##STR00080## wherein the asterisk symbol “*” represents the binding positions of L.
9. The organic electronic device of claim 1, whereby at least one of R.sup.1 to R.sup.4 or Ar may be selected from pyridine, quinolone, isoquinolone, indole, acridine, benzoacridine, dibenzoacridines, phenanthrodine, carbazole, indole, benzoindole, pyrimidine, pyrazine, quinozoline, pyrazole, quinoxaline, phenazine, naphthyridine, phananthrodine, azacarbazole, benzimidazole, benzooxazole, benzothiazole, nezotriazole, benzooxadiazole, benzothiadiazole, benzothiphene, benzofurane, dibenzofurane, dibenzothiophene, naphthofurane, naphthothiophene, and phenanthroline.
10. The organic electronic device of claim 1, whereby the organic semiconductor layer comprises a redox n-dopant.
11. The organic electronic device of claim 1, whereby the organic semiconductor layer is an electron-transport layer.
12. The organic electronic device of claim 1, whereby the organic semiconductor layer is a charge-generation layer.
13. The organic electronic device of claim 1, whereby the organic electronic device is an electroluminescent device.
14. A display device comprising an organic electronic device according to claim 1.
15. A C.sub.s-symmetric compound of Formula (1): ##STR00081## wherein R.sup.1-R.sup.4 are independently selected from a substituted or unsubstituted C.sub.6-C.sub.36 aryl, and a substituted or unsubstituted C.sub.3-C.sub.36 heteroaryl; wherein at least one of the R.sup.1-R.sup.4 is selected from C.sub.3-C.sub.36 heteroaryl group or heteroarylene group which is directly attached to the pyrazine ring in formula 1 and at least three of R.sup.1-R.sup.4 are different to each other; wherein, if substituent(s) are present in R.sup.1, R.sup.2, R.sup.3, and R.sup.4, the substituent(s) are independently selected from the groups consisting of C.sub.6-C.sub.18 aryl, C.sub.3-C.sub.20 heteroaryl, D, F, CN, C.sub.1-C.sub.16 alkyl, C.sub.1-C.sub.16 alkoxy, PY(R).sub.2, OR, SR, (C═O)R, (C═O)N(R).sub.2, Si(R).sub.3, (S═O)R, and ##STR00082## whereby Y is O or S; and R is independently selected from C.sub.1-C.sub.20 linear alkyl, C.sub.1-C.sub.20 alkoxy, C.sub.1-C.sub.20 thioalkyl, C.sub.3-C.sub.20 branched alkyl, C.sub.3-C.sub.20 cyclic alkyl, C.sub.3-C.sub.20 branched alkoxy, C.sub.3-C.sub.20 cyclic alkoxy, C.sub.3-C.sub.20 branched thioalkyl, C.sub.3-C.sub.20 cyclic thioalkyl, C.sub.6-C.sub.20 aryl and C.sub.3-C.sub.20 heteroaryl; and wherein the following compounds 1-4 are excluded: ##STR00083##
Description
DESCRIPTION OF THE DRAWINGS
[0242] The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations.
[0243] Additional details, characteristics and advantages of the object of the invention are disclosed in the dependent claims and the following description of the respective figures which in an exemplary fashion show preferred embodiments according to the invention. Any embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention as claimed.
[0244]
[0245]
[0246]
[0247]
[0248] Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.
[0249] Herein, when a first element is referred to as being formed or disposed “on” or “onto” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” or “directly onto” a second element, no other elements are disposed there between.
[0250]
[0251]
[0252] Instead of a single electron transport layer 160, optionally an electron transport layer stack (ETL) can be used.
[0253]
[0254] Referring to
[0255] Preferably, the organic semiconductor layer comprising a compound of Formula (1) may be an ETL.
[0256]
[0257] Referring to
[0258] Preferably, the organic semiconductor layer comprising a compound of Formula (1) may be an n-type CGL.
[0259] Preferably, the organic semiconductor layer comprising a compound of Formula (1) may be the first ETL, n-type CGL and/or second ETL.
[0260] While not shown in
[0261] Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples.
DETAILED DESCRIPTION
[0262] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.
Experimental Part
[0263] 1) General Procedure for the Synthesis of Compound of Formula 1
[0264] In a first step intermediate compound 1 was synthesized as follow:
##STR00052##
[0265] A flask was flushed with nitrogen and charged with reagent A (33.2 mmol), reagent B (26.6 mmol), Pd(PPh.sub.3).sub.4 (1.7 mmol), and K.sub.2CO.sub.3 (83.0 mmol). A mixture of deaerated Toluene/THF/water (1:1:1 81 mL) was added and the reaction mixture was heated to 65° C. under a nitrogen atmosphere during two hours. After cooling down to 0° C., the resulting precipitate was isolated by suction filtration washed with toluene (3×20 mL) and dried. The crude product was then dissolved in chloroform (300 mL) and the organic phase was washed with water (3×100 mL). After drying over MgSO.sub.4, the organic phase was filtered through a silicagel pad. After rinsing with additional chloroform (1000 mL), the solvents were removed under reduced pressure. Dichloromethane (20 mL) and isopropanol (40 mL) were added and then the dichloromethane was slowly removed under reduced pressure to induce precipitation. After filtration, the crude solid was dissolved in dichloromethane (30 mL) and hexane (60 mL) was added to induce precipitation. The precipitate was collected by suction filtration to yield intermediate 1 after drying. Purity was determined by HPLC.
[0266] In the second step compound of formula 1 is synthesized using standard borylation reaction as follow:
##STR00053##
[0267] A flask was flushed with nitrogen and charged with intermediate 1 (11.9 mmol), reagent C (11.9 mmol), Pd(dppf)Cl.sub.2 (0.2 g, 0.24 mmol), and K.sub.2CO.sub.3 (3.3 g, 23.8 mmol). A mixture of deaerated THF/water (4:1, 60 mL) was added and the reaction mixture was heated to 65° C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration, washed with hexane (250 mL), water (1000 mL) and methanol (2×50 mL). The crude product was dried, dissolved in hot chlorobenzene (500 mL) and filtered through a silicagel pad. After rinsing with additional chlorobenzene (500 mL), the solvents were partially removed under reduced pressure. Hexane (200 mL) was added to induce precipitation. After filtration, the product was recrystallized in chlorobenzene (100 mL) to yield compound of formula 1 after drying. Final purification was achieved by sublimation.
[0268] 2) General Procedure for the Synthesis of Compound of Formula 1
[0269] In a first step intermediate compound 1 was synthesized as follow:
##STR00054##
[0270] A flask was flushed with nitrogen and charged with Reagent A-1 (59.9 mmol), reagent B (75.0 mmol), Pd(PPh.sub.3).sub.2Cl.sub.2 (2.1 g, 3.0 mmol), and K.sub.2CO.sub.3 (33.1 g, 239.6 mmol). A mixture of deaerated THF/water (3:1, 400 mL) was added and the reaction mixture was heated to 55° C. under a nitrogen atmosphere during three hours. After cooling down to room temperature, reaction mixture was washed with water and the organic phase was dried over MgSO.sub.4. Solvents were removed under reduced pressure, residue was dissolved in hot dichloromethane, embedded onto silicagel and purified by column chromatography using as eluent dichloromethane/petroleum ether (3:10, 1 L—3.5:10, 1 L—4:10, 2 L) and dichloromethane. Solvents were evaporated and solid was dissolved in hot dichloromethane, giving a turbid solution. Remaining solids were filtered off and discarded. Solution was cooled down, solvents were partially removed under reduced pressure and petroleum ether (900 mL) was added to induce precipitation. Solid was filtered and recrystallized in dioxane (270 mL) to yield intermediate 1-1.
[0271] In the second step compound of formula 1-1 is synthesized using standard borylation reaction as follow:
##STR00055##
[0272] A flask was flushed with nitrogen and charged Intermediate 1-1 (59.9 mmol), reagent D (12.8 g, 75.0 mmol), Pd(PPh.sub.3).sub.2Cl.sub.2 (2.1 g, 3.0 mmol), and K.sub.2CO.sub.3 (33.1 g, 239.6 mmol). A mixture of deaerated THF/water (3:1, 400 mL) was added and the reaction mixture was heated to 55° C. under a nitrogen atmosphere during three hours. After cooling down to room temperature, reaction mixture was washed with water and the organic phase was dried over MgSO.sub.4. Solvents were removed under reduced pressure, residue was dissolved in hot dichloromethane, embedded onto silicagel and purified by column chromatography using as eluent dichloromethane/petroleum ether (3:10, 1 L—3.5:10, 1 L—4:10, 2 L) and dichloromethane. Solvents were evaporated and solid was dissolved in hot dichloromethane, giving a turbid solution. Remaining solids were filtered off and discarded. Solution was cooled down, solvents were partially removed under reduced pressure and petroleum ether (900 mL) was added to induce precipitation. Solid was filtered and recrystallized in dioxane (270 mL) to yield compound of formula 1-1.
Synthesis of 2,3,5-triphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine
First Step: Synthesis of 2-chloro-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine
[0273] ##STR00056##
[0274] A flask was flushed with nitrogen and charged with 2,3-dichloro-5,6-diphenylpyrazine (10.0 g, 33.2 mmol), dibenzo[b,d]furan-3-ylboronic acid (5.6 g, 26.6 mmol), Pd(PPh.sub.3).sub.4 (1.9 g, 1.7 mmol), and K.sub.2CO.sub.3 (11.5 g, 83.0 mmol). A mixture of deaerated Toluene/THF/water (1:1:1, 81 mL) was added and the reaction mixture was heated to 65° C. under a nitrogen atmosphere during two hours. After cooling down to 0° C., the resulting precipitate was isolated by suction filtration washed with toluene (3×20 mL) and dried. The crude product was then dissolved in chloroform (300 mL) and the organic phase was washed with water (3×100 mL). After drying over MgSO.sub.4, the organic phase was filtered through a silicagel pad. After rinsing with additional chloroform (1000 mL), the solvents were removed under reduced pressure. Dichloromethane (20 mL) and isopropanol (40 mL) were added and then the dichloromethane was slowly removed under reduced pressure to induce precipitation. After filtration, the crude solid was dissolved in dichloromethane (30 mL) and hexane (60 mL) was added to induce precipitation. The precipitate was collected by suction filtration to yield 3.4 g (30%) of 2-chloro-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine after drying. HPLC: 98.8%
Second Step: 2,3,5-triphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine was Synthesized from 943442-81-7, Using Standard Borylation Reaction
[0275] ##STR00057##
[0276] A flask was flushed with nitrogen and charged with 2-chloro-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine (5.1 g, 11.9 mmol), 2,3,5-triphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine (6.1 g, 11.9 mmol), Pd(dppf)Cl.sub.2 (0.2 g, 0.24 mmol), and K.sub.2CO.sub.3 (3.3 g, 23.8 mmol). A mixture of deaerated THF/water (4:1, 60 mL) was added and the reaction mixture was heated to 65° C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration, washed with hexane (250 mL), water (1000 mL) and methanol (2×50 mL). The crude product was dried, dissolved in hot chlorobenzene (500 mL) and filtered through a silicagel pad. After rinsing with additional chlorobenzene (500 mL), the solvents were partially removed under reduced pressure. Hexane (200 mL) was added to induce precipitation. After filtration, the product was recrystallized in chlorobenzene (100 mL) to yield 5.7 g (61%) of 2,3,5-triphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.8%, m/z=781 ([M+H].sup.+), 781 ([M+H].sup.+).
Synthesis of 2-(dibenzo[b,d]furan-3-yl)-5,6-diphenyl-3-(4-(pyridin-3-yl)phenyl)pyrazine
[0277] ##STR00058##
[0278] A flask was flushed with nitrogen and charged with 2-chloro-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine (6.0 g, 13.7 mmol), 3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine (4.2 g, 15.1 mmol), Pd(dppf)Cl.sub.2 (0.2 g, 0.27 mmol), and K.sub.2CO.sub.3 (3.8 g, 27.4 mmol). A mixture of deaerated THF/water (4:1, 70 mL) was added and the reaction mixture was heated to 65° C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration washed with water (2×50 mL) and with methanol (2×50 mL). The crude product was dried, dissolved in dichloromethane (150 mL) and washed with an aqueous solution of sodium diethyldithiocarbamate trihydrate and then with water. After drying over MgSO.sub.4, it was filtered through a silicagel pad. After rinsing with additional dichloromethane (1000 mL) and dichloromethane/methanol (100:3, 2500 mL), solvents were partially removed under reduced pressure to 100 mL. Suspension was filtered to yield 4.8 g (63%) of 2-(dibenzo[b,d]furan-3-yl)-5,6-diphenyl-3-(4-(pyridin-3-yl)phenyl)pyrazine after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.9%, m/z=552 ([M+H].sup.+).
Synthesis of 4″-(3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazin-2-yl)-[1,1′:4′,1″-terphenyl]-4-carbonitrile
[0279] ##STR00059##
[0280] A flask was flushed with nitrogen and charged with 2-chloro-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine (2.8 g, 6.4 mmol), 4″-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′:4′,1″-terphenyl]-4-carbonitrile (2.6 g, 6.8 mmol), Pd(dppf)Cl.sub.2 (0.09 g, 0.13 mmol), and K.sub.2CO.sub.3 (1.8 g, 12.9 mmol). A mixture of deaerated THF/water (10:1, 55 mL) was added and the reaction mixture was heated to 85° C. under a nitrogen atmosphere over two days. After cooling down to room temperature, solvents were removed under reduced pressure, the residue was dissolved in dichloromethane (100 mL), washed with water (3×100 mL) and dried over MgSO.sub.4. Residue was embedded in silicagel and filtered through a silicagel pad, using as eluent hexane/dichloromethane (3:2, 500 mL) and hexane/dichloromethane (1:1, 1 L). Suspension was filtered to yield 2.5 g (60%) of 4″-(3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazin-2-yl)-[1,1′:4′,1″-terphenyl]-4-carbonitrile after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.9%, m/z=652 ([M+H].sup.+).
Synthesis of (4′-(3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazin-2-yl)-[1,1′-biphenyl]-3-yl)dimethylphosphine oxide
First Step: Synthesis of 2-(4-chlorophenyl)-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine
[0281] ##STR00060##
[0282] A flask was flushed with nitrogen and charged with 2-chloro-3-(4-chlorophenyl)-5,6-diphenylpyrazine (22.8 g, 59.9 mmol), dibenzo[b,d]furan-3-ylboronic acid (12.8 g, 75.0 mmol), Pd(PPh.sub.3).sub.2Cl.sub.2 (2.1 g, 3.0 mmol), and K.sub.2CO.sub.3 (33.1 g, 239.6 mmol). A mixture of deaerated THF/water (3:1, 400 mL) was added and the reaction mixture was heated to 55° C. under a nitrogen atmosphere during three hours. After cooling down to room temperature, reaction mixture was washed with water and the organic phase was dried over MgSO.sub.4. Solvents were removed under reduced pressure, residue was dissolved in hot dichloromethane, embedded onto silicagel and purified by column chromatography using as eluent dichloromethane/petroleum ether (3:10, 1 L—3.5:10, 1 L—4:10, 2 L) and dichloromethane. Solvents were evaporated and solid was dissolved in hot dichloromethane, giving a turbid solution. Remaining solids were filtered off and discarded. Solution was cooled down, solvents were partially removed under reduced pressure and petroleum ether (900 mL) was added to induce precipitation. Solid was filtered and recrystallized in dioxane (270 mL) to yield 55.9 g (96%) of 2-(4-chlorophenyl)-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine after drying. HPLC: 99.0%
Second Step: (4′-(3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazin-2-yl)-[1,1′-biphenyl]-3-yl)dimethylphosphine oxide was Synthesized Using Standard Borylation Reaction
[0283] ##STR00061##
[0284] A flask was flushed with nitrogen and charged with 2-(4-chlorophenyl)-3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazine (10.0 g, 19.6 mmol), dimethyl(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)phosphine oxide (7.1 g, 25.6 mmol), chloro(crotyl)(2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl)palladium(II) (0.24 g, 0.4 mmol), and K.sub.3PO.sub.4 (8.3 g, 39.3 mmol). A mixture of deaerated Dioxane/water (4:1) was added and the reaction mixture was heated to 45° C. under a nitrogen atmosphere during three days. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration washed with dioxane (3×20 mL), with water (800 mL) and with methanol (2×50 mL). The crude product was dried, dissolved in dichloromethane/methanol (100:2, 400 mL) and filtered through a silicagel pad. After rinsing with additional dichloromethane/methanol (100:2, 1700 mL+100:5, 400 mL), the solvents were partially removed under reduced pressure. Hexane was added to induce precipitation. After filtration, the product was recrystallized in toluene to yield 7.5 g (610%) of (4′-(3-(dibenzo[b,d]furan-3-yl)-5,6-diphenylpyrazin-2-yl)-[1,1′-biphenyl]-3-yl)dimethylphosphine oxide after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 100%, m/z=627 ([M+H].sup.+).
TABLE-US-00001 TABLE 1 Properties of compound of Formula 1 Diplole HOMO LUMO moment mp Tg T.sub.RO Compounds of Formula 1 (eV) (eV) (Debye) (° C.) (° C.) (° C.)
General Procedure 1 for Fabrication of OLEDs
[0285] A top emission device was made by depositing an anode of 100 nm thick Ag on a glass substrate.
[0286] Then, 92 vol.-% N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (CAS 1242056-42-3) with 8 vol.-% 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) was vacuum deposited on the anode, to form a HIL having a thickness of 10 nm. Then, N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine was vacuum deposited on the HIL, to form a HTL having a thickness of 128 nm.
[0287] Then, N-(4-(dibenzo[b,d]furan-4-yl)phenyl)-N-(4-(9-phenyl-9H-fluoren-9-yl)phenyl)-[1,1′-biphenyl]-4-amine was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
[0288] Then, 97 vol.-% H09 (Sun Fine Chemicals, Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue dopant were deposited on the EBL, to form a blue-emitting EML with a thickness of 20 nm.
[0289] Then the auxiliary electron transport layer (ETL-1) was formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer (EML).
[0290] Then, the electron transporting layer 2 (ETL-2) was formed on the auxiliary electron transport layer (ETL-1) by depositing the compound of Formula (1) according to the inventive example 1 to example X and comparative compound 1 according to the comparative example 1 with a the thickness of 31 nm. The electron transport layer 2 (ETL-2) comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ, see Table 2.
[0291] Then, the electron injection layer was formed on the electron transporting layer 2 by deposing Yb with a thickness of 2 nm.
[0292] Ag:Mg (90:10) was co-deposited at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode with a thickness of 11 nm.
[0293] 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.
[0294] General procedure for fabrication of a tandem OLED device.
[0295] A top emission device was made by depositing an anode of 100 nm thick Ag on a glass substrate.
[0296] Then, 97 vol.-% Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 3 vol.-% 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) was vacuum deposited on the anode, to form a HIL having a thickness of 10 nm.
[0297] Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the HIL, to form a first HTL having a thickness of 128 nm.
[0298] Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form a first electron blocking layer (EBL) having a thickness of 5 nm.
[0299] Then 97 vol.-% H09 (Sun Fine Chemicals, South Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, South Korea) as fluorescent blue dopant were deposited on the EBL, to form a first blue-emitting EML with a thickness of 20 nm.
[0300] Then the first hole blocking layer is formed with a thickness of 5 nm by 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile on the emission layer.
[0301] Then, the first electron transporting layer having a thickness of 25 nm is formed on the hole blocking layer by depositing 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile. The electron transport layer (ETL) comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ.
[0302] Then the first n-CGL was formed on ETL with a thickness of 15 nm. The n-CGL comprises organic compound of formula 1 and metal dopant (Table 3). Then the p-CGL was formed on n-CGL with a thickness of 10 nm on n-CGL by depositing 90 vol.-% Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 10 vol.-% 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile).
[0303] Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited to form a second HTL having a thickness of 10 nm.
[0304] Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form a second electron blocking layer (EBL) having a thickness of 5 nm.
[0305] Then 97 vol.-% H09 (Sun Fine Chemicals, South Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, South Korea) as fluorescent blue dopant were deposited on the EBL, to form a second blue-emitting EML with a thickness of 20 nm.
[0306] Then the second hole blocking layer is formed with a thickness of 5 nm by 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile on the emission layer.
[0307] Then, the second electron transporting layer having a thickness of 25 nm is formed on the hole blocking layer by depositing 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile. The electron transport layer (ETL) comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ.
[0308] Then the second n-CGL was formed on ETL with a thickness of 15 nm. The n-CGL comprises organic compound of formula 1 and metal dopant (Table 3). Then the p-CGL was formed on n-CGL with a thickness of 10 nm on n-CGL by depositing 90 vol.-% Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 10 vol.-% 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile).
[0309] Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the HIL, to form a third HTL having a thickness of 10 nm.
[0310] Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form third electron blocking layer (EBL) having a thickness of 5 nm.
[0311] Then 97 vol.-% H09 (Sun Fine Chemicals, South Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, South Korea) as fluorescent blue dopant were deposited on the EBL, to form a third blue-emitting EML with a thickness of 20 nm.
[0312] Then the third hole blocking layer is formed with a thickness of 5 nm by 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile on the emission layer.
[0313] Then, the third electron transporting layer having a thickness of 25 nm is formed on the hole blocking layer by depositing 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile. The electron transport layer (ETL) comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ.
[0314] An electron injecting layer is formed by depositing Yb with a thickness of 2 nm.
[0315] A cathode with a thickness of 100 nm is formed by depositing Ag:Mg (90:10) at the rate of 0.01 to 1 Å/s at 10.sup.−7 mbar.
[0316] A capping layer is formed by depositing N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine with a thickness of 60 nm.
[0317] 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.
[0318] 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.
[0319] To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing a voltage in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m.sup.2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.
[0320] Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm.sup.2, using a Keithley 2400 sourcemeter, and recorded in hours.
[0321] 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.
Technical Effect
[0322] Surprisingly, it was found that the organic electronic device comprising organic semiconductor layer comprising compound of formula 1 according to the present invention solve the problem underlying by being superior over the organic electronic device known in the art, in particular with respect to operating voltage, which is important for reducing power consumption and increasing battery life, for example of a mobile display device. At the same time the cd/A efficiency, also referred to as current efficiency is kept at a similar or even improved level. Long life time at high current density is important for the longevity of a device which run at high brightness.
[0323] The beneficial effect of the invention on the performance of organic electronic devices can be seen in Table 2 and Table 3.
[0324] Table 2 shows the performance of OLED device comprising an ETL comprising compound of formula 1.
TABLE-US-00002 Conc. of matrix cd/A Alkali compound and Thickness Operating efficiency at organic alkali organic ETL voltage at 10 10 mA/cm.sup.2 Example Matrix compound complex complex (vol.-%) (nm) mA/cm.sup.2 (V) (cd/A) Comparative example 1
[0325] The OLED device of inventive Example 1-3 comprising electron transport layer comprising the compound of formula 1 showed an improved efficiency (cd/A at 10 mA/cm.sup.2) and low operating voltage (10 mA/cm.sup.2 (V)) as compared to the OLED device of comparative example 1-3 comprising electron transport layer comprising comparative compound C-1 to C-3.
TABLE-US-00003 TABLE 3 Performance of a tandem organic electronic device comprising an n-CGL comprising first compound of formula 1 and a metal dopant 1.sup.st and 2.sup.nd Thickness Operating LT97 Metal n-CGL n-CGL voltage at 15 CEff/(cd/A) 30mA/cm.sup.2 Example Matrix compound dopant (vol.-%) (nm) mA/cm.sup.2 (V) [15 mA/cm.sup.2] (h) Comparative Example 4
[0326] The tandem OLED device of inventive Example 4-5 comprising an n-CGL comprising the compound of formula 1 showed an improved efficiency (cd/A at 10 mA/cm.sup.2), long life (LT9730 mA/cm.sup.2) and low operating voltage (15 mA/cm.sup.2 (V)) as compared to the OLED device of Comparative example 4 comprising an n-CGL comprising comparative C-4.
[0327] The results show that in comparison with state-of-art reference, the compounds according to invention show a clearly enhanced performance, especially with reference to the efficiency (cd/A at 10 mA/cm.sup.2), long lifetime (LT9730 mA/cm.sup.2) and low operating voltage (10 mA/cm.sup.2 (V)). The OLED device of inventive Example 1-3 comprising electron transport layer comprising the compound of formula 1 showed an improved efficiency (cd/A at 10 mA/cm.sup.2) and low operating voltage (10 mA/cm.sup.2 (V)) as compared to the OLED device of comparative example 1-3 comprising electron transport layer comprising comparative compound C-1 to C-3. The tandem OLED device of inventive Example 4-5 comprising an n-CGL comprising the compound of formula 1 showed an improved efficiency (cd/A at 10 mA/cm.sup.2), long lifetime (LT9730 mA/cm.sup.2) and low operating voltage (15 mA/cm.sup.2 (V)) as compared to the OLED device of Comparative example 4 comprising an n-CGL comprising comparative C-4.
[0328] The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by way of example only and is not intended as limiting. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.
[0329] Methods:
[0330] Melting Point
[0331] The melting point (mp) is determined as peak temperatures from the DSC curves of the above TGA-DSC measurement or from separate DSC measurements (Mettler Toledo DSC822e, heating of samples from room temperature to completeness of melting with heating rate 10 K/min under a stream of pure nitrogen. Sample amounts of 4 to 6 mg are placed in a 40 pL Mettler Toledo aluminum pan with lid, a <1 mm hole is pierced into the lid).
[0332] Glass Transition Temperature
[0333] The glass transition temperature (Tg) is measured under nitrogen and using a heating rate of 10 K per min in a Mettler Toledo DSC 822e differential scanning calorimeter as described in DIN EN ISO 11357, published in March 2010.
[0334] Rate Onset Temperature
[0335] The rate onset temperature (T.sub.RO) is determined by loading 100 mg compound into a VTE source. As VTE source a point source for organic materials may be used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10.sup.−5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the compound is detected with a QCM detector which detects deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in {acute over (Å)}ngstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTE source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.
[0336] To achieve good control over the evaporation rate of an organic compound, the rate onset temperature may be in the range of 200 to 255° C. If the rate onset temperature is below 200° C. the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is above 255° C. the evaporation rate may be too low which may result in low tact time and decomposition of the organic compound in VTE source may occur due to prolonged exposure to elevated temperatures.
[0337] The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.
[0338] Reduction Potential
[0339] The reduction potential is determined by cyclic voltammetry with potenioststic device Metrohm PGSTAT30 and software Metrohm Autolab GPES at room temperature. The redox potentials given at particular compounds were measured in an argon de-aerated, dry 0.1M THF solution of the tested substance, under argon atmosphere, with 0.1M tetrabutylammonium hexafluorophosphate supporting electrolyte, between platinum working electrodes and with an Ag/AgCl pseudo-standard electrode (Metrohm Silver rod electrode), consisting of a silver wire covered by silver chloride and immersed directly in the measured solution, with the scan rate 100 mV/s. The first run was done in the broadest range of the potential set on the working electrodes, and the range was then adjusted within subsequent runs appropriately. The final three runs were done with the addition of ferrocene (in 0.1M concentration) as the standard. The average of potentials corresponding to cathodic and anodic peak of the studied compound, after subtraction of the average of cathodic and anodic potentials observed for the standard Fc.sup.+/Fc redox couple, afforded finally the values reported above. All studied compounds as well as the reported comparative compounds showed well-defined reversible electrochemical behaviour.
[0340] Dipole Moment
[0341] The dipole moment μ{right arrow over (|)} of a molecule containing N atoms is given by:
[0342] where q.sub.i and {right arrow over (r.sub.i)} are the partial charge and position of atom i in the molecule.
[0343] The dipole moment is determined by a semi-empirical molecular orbital method.
[0344] The geometries of the molecular structures are optimized using the hybrid functional B3LYP with the 6-31G* basis set in the gas phase as implemented in the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). If more than one conformation is viable, the conformation with the lowest total energy is selected to determine the bond lengths of the molecules.
[0345] Calculated HOMO and LUMO
[0346] The HOMO and LUMO are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected.