ORGANIC ELECTROLUMINESCENT DEVICE

Abstract

The triarylamine compound having a specific structure in the present invention is excellent in hole injection/transport ability, stability and durability of thin film. By selecting the triarylamine compound having a specific structure as the material for the hole transport layer, holes injected from the anode side can be efficiently transported. Furthermore, various organic EL devices combining luminescent materials having a specific structure or the like exhibit good device characteristics. The triarylamine compound having a specific structure in the present invention is excellent in hole injection/transport ability, stability and durability of thin film. By selecting the triarylamine compound having a specific structure as the material for the hole transport layer, holes injected from the anode side can be efficiently transported. Furthermore, various organic EL devices combining luminescent materials having a specific structure or the like exhibit good device characteristics.

Claims

1. An organic electroluminescence device comprising at least a first hole transport layer, a second hole transport layer, a blue light emitting layer and an electron transport layer in this order from the anode side between anode and cathode, wherein the second hole transport layer, or at least one layer of the laminated layers disposed between the first hole transport layer and the electron transport layer comprises a triarylamine compound represented by the following general formula (1): ##STR00033## wherein A, B, and C may be the same or different, and represent a monovalent group of the general formula (2-1), where the dashed part is the bonding site, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group. However, all of A, B and C shall not simultaneously be monovalent groups represented by the following general formula (2-1). ##STR00034## wherein the dashed part is the binding site. R represents a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms that may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms that may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms that may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. n is the number of R and represents an integer between 0 and 3. When n is 2 or 3, a plurality of R which bind to the same benzene ring, may be the same or different and may bind to each other via a single bond, substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom to form a ring. L represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon, a divalent group of a substituted or unsubstituted aromatic heterocyclic ring, or a divalent group of substituted or unsubstituted condensed polycyclic aromatics. m represents an integer between 1 and 3. When m is 2 or 3, L may be the same or different. Ar.sub.1 and Ar.sub.2 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted condensed polycyclic aromatic group.

2. The organic electroluminescent device according to claim 1, wherein the monovalent group represented by the general formula (2-1) is the monovalent group represented by the following general formula (2-2): ##STR00035## wherein the dashed part is the binding site. Ar.sub.1, Ar.sub.2, L, m, n and R are the same as defined by the general formula (2-1).

3. The organic electroluminescent device according to claim 1, wherein the monovalent group represented by the general formula (2-1) is the monovalent group represented by the following general formula (2-3): ##STR00036## wherein the dashed part is the binding site. Ar.sub.1, Ar.sub.2, n and R are the same as defined by the general formula (2-1). p represents 0 or 1.

4. The organic electroluminescent device according to claim 1, wherein the monovalent group represented by the general formula (2-1) is the monovalent group represented by the following general formula (2-4): ##STR00037## wherein the dashed part is the binding site. Ar.sub.1, and Ar.sub.2 are the same as defined by the general formula (2-1). p represents 0 or 1.

5. The organic electroluminescent device according to claim 1, wherein the blue light emitting layer includes a blue light emitting dopant.

6. The organic electroluminescent device according to claim 5, wherein the blue light emitting dopant is a compound represented by the following general formula (3-1) or general formula (3-2). ##STR00038## wherein, Q.sub.1 to Q.sub.3 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted condensed polycyclic aromatics, or a substituted or unsubstituted aromatic heterocyclic ring. X represents B, P, P═O, or P═S. Y.sub.1 to Y.sub.3 may be the same or different, and represent one of selected from N—R.sub.4, CR.sub.5R.sub.6, O, S, Se and SiR.sub.7R.sub.8. R.sub.4 to R.sub.8 may be the same or different, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms that may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms that may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms that may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. R.sub.5 and R.sub.6, and R.sub.7 and R.sub.8 may bind to each other to form a ring via a single bond, substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. When Y.sub.1 to Y.sub.3 are N—R.sub.4, CR.sub.5R.sub.6, or SiR.sub.7R.sub.8, R.sub.4 to R.sub.8 may bind to the adjacent Q.sub.1, Q.sub.2, or Q.sub.3, respectively, to form a ring via a linking group, such as substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group.

7. The organic electroluminescent device according to claim 1, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

8. The organic electroluminescent device according to claim 2, wherein the blue light emitting layer includes a blue light emitting dopant.

9. The organic electroluminescent device according to claim 3, wherein the blue light emitting layer includes a blue light emitting dopant.

10. The organic electroluminescent device according to claim 4, wherein the blue light emitting layer includes a blue light emitting dopant.

11. The organic electroluminescent device according to claim 8, wherein the blue light emitting dopant is a compound represented by the following general formula (3-1) or general formula (3-2). ##STR00039## wherein, Q.sub.1 to Q.sub.3 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted condensed polycyclic aromatics, or a substituted or unsubstituted aromatic heterocyclic ring. X represents B, P, P═O, or P═S. Y.sub.1 to Y.sub.3 may be the same or different, and represent one of selected from N—R.sub.4, CR.sub.5R.sub.6, O, S, Se and SiR.sub.7R.sub.8. R.sub.4 to R.sub.8 may be the same or different, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms that may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms that may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms that may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. R.sub.5 and R.sub.6, and R.sub.7 and R.sub.8 may bind to each other to form a ring via a single bond, substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. When Y.sub.1 to Y.sub.3 are N—R.sub.4, CR.sub.5R.sub.6, or SiR.sub.7R.sub.8, R.sub.4 to R.sub.8 may bind to the adjacent Q.sub.1, Q.sub.2, or Q.sub.3, respectively, to form a ring via a linking group, such as substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group.

12. The organic electroluminescent device according to claim 9, wherein the blue light emitting dopant is a compound represented by the following general formula (3-1) or general formula (3-2). ##STR00040## wherein, Q.sub.1 to Q.sub.3 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted condensed polycyclic aromatics, or a substituted or unsubstituted aromatic heterocyclic ring. X represents B, P, P═O, or P═S. Y.sub.1 to Y.sub.3 may be the same or different, and represent one of selected from N—R.sub.4, CR.sub.5R.sub.6, O, S, Se and SiR.sub.7R.sub.8. R.sub.4 to R.sub.8 may be the same or different, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms that may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms that may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms that may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. R.sub.5 and R.sub.6, and R.sub.7 and R.sub.8 may bind to each other to form a ring via a single bond, substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. When Y.sub.1 to Y.sub.3 are N—R.sub.4, CR.sub.5R.sub.6, or SiR.sub.7R.sub.8, R.sub.4 to R.sub.8 may bind to the adjacent Q.sub.1, Q.sub.2, or Q.sub.3, respectively, to form a ring via a linking group, such as substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group.

13. The organic electroluminescent device according to claim 10, wherein the blue light emitting dopant is a compound represented by the following general formula (3-1) or general formula (3-2). ##STR00041## wherein, Q.sub.1 to Q.sub.3 may be the same or different, and represent a substituted or unsubstituted aromatic hydrocarbon, a substituted or unsubstituted condensed polycyclic aromatics, or a substituted or unsubstituted aromatic heterocyclic ring. X represents B, P, P═O, or P═S. Y.sub.1 to Y.sub.3 may be the same or different, and represent one of selected from N—R.sub.4, CR.sub.5R.sub.6, O, S, Se and SiR.sub.7R.sub.8. R.sub.4 to R.sub.8 may be the same or different, and represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a linear or branched alkyl group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyl group of 5 to 10 carbon atoms that may have a substituent, a linear or branched alkenyl group of 2 to 6 carbon atoms that may have a substituent, a linear or branched alkyloxy group of 1 to 6 carbon atoms that may have a substituent, a cycloalkyloxy group of 5 to 10 carbon atoms that may have a substituent, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted aryloxy group. R.sub.5 and R.sub.6, and R.sub.7 and R.sub.8 may bind to each other to form a ring via a single bond, substituted or unsubstituted methylene group, an oxygen atom, or a sulfur atom. When Y.sub.1 to Y.sub.3 are N—R.sub.4, CR.sub.5R.sub.6, or SiR.sub.7R.sub.8, R.sub.4 to R.sub.8 may bind to the adjacent Q.sub.1, Q.sub.2, or Q.sub.3, respectively, to form a ring via a linking group, such as substituted or unsubstituted methylene group, an oxygen atom, a sulfur atom, or a monosubstituted amino group.

14. The organic electroluminescent device according to claim 2, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

15. The organic electroluminescent device according to claim 3, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

16. The organic electroluminescent device according to claim 4, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

17. The organic electroluminescent device according to claim 5, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

18. The organic electroluminescent device according to claim 6, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

19. The organic electroluminescent device according to claim 8, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

20. The organic electroluminescent device according to claim 9, wherein the blue light emitting layer includes an anthracene derivative having an anthracene skeleton in the molecule.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0093] FIG. 1 is a figure showing the structural formula of the compound 1-1 to 1-12 as examples of triarylamine compound represented by the general formula (1).

[0094] FIG. 2 is a figure showing the structural formula of the compound 1-13 to 1-24 as examples of triarylamine compound represented by the general formula (1).

[0095] FIG. 3 is a figure showing the structural formula of the compound 1-25 to 1-36 as examples of triarylamine compound represented by the general formula (1).

[0096] FIG. 4 is a figure showing the structural formula of the compound 1-37 to 1-48 as examples of triarylamine compound represented by the general formula (1).

[0097] FIG. 5 is a figure showing the structural formula of the compound 1-49 to 1-60 as examples of triarylamine compound represented by the general formula (1).

[0098] FIG. 6 is a figure showing the structural formula of the compound 1-61 to 1-72 as examples of triarylamine compound represented by the general formula (1).

[0099] FIG. 7 is a figure showing the structural formula of the compound 1-73 to 1-84 as examples of triarylamine compound represented by the general formula (1).

[0100] FIG. 8 is a figure showing the structural formula of the compound 1-85 to 1-95 as examples of triarylamine compound represented by the general formula (1).

[0101] FIG. 9 is a figure showing the structural formula of the compound 1-96 to 1-107 as examples of triarylamine compound represented by the general formula (1).

[0102] FIG. 10 is a figure showing the structural formula of the compound 1-108 to 1-119 as examples of triarylamine compound represented by the general formula (1).

[0103] FIG. 11 is a figure showing the structural formula of the compound 1-120 to 1-131 as examples of triarylamine compound represented by the general formula (1).

[0104] FIG. 12 is a figure showing the structural formula of the compound 1-132 to 1-142 as examples of triarylamine compound represented by the general formula (1).

[0105] FIG. 13 is a figure showing the structural formula of the compound 1-143 to 1-154 as examples of triarylamine compound represented by the general formula (1).

[0106] FIG. 14 is a figure showing the structural formula of the compound 1-155 to 1-166 as examples of triarylamine compound represented by the general formula (1).

[0107] FIG. 15 is a figure showing the structural formula of the compound 1-167 to 1-178 as examples of triarylamine compound represented by the general formula (1).

[0108] FIG. 16 is a figure showing the structural formula of the compound 1-179 to 1-190 as examples of triarylamine compound represented by the general formula (1).

[0109] FIG. 17 is a figure showing the structural formula of the compound 1-191 to 1-201 as examples of triarylamine compound represented by the general formula (1).

[0110] FIG. 18 is a figure showing the structural formula of the compound 3-1-1 to 3-1-9 as examples of compound represented by the general formula (3-1).

[0111] FIG. 19 is a figure showing the structural formula of the compound 3-1-10 to 3-1-24 as examples of compound represented by the general formula (3-1).

[0112] FIG. 20 is a figure showing the structural formula of the compound 3-2-1 to 3-2-6 as examples of compound represented by the general formula (3-2).

[0113] FIG. 21 is a diagram illustrating as examples of the configuration of the organic EL devices in the present invention.

MODE FOR CARRYING OUT THE INVENTION

[0114] The specific examples of preferred compounds among the triarylamine compounds represented by the general formula (1) preferably used in the organic EL device of the present invention is showing in FIGS. 1 to 17. The present invention, however, is not restricted to these compounds.

[0115] The specific examples of preferred compounds among the compounds represented by the general formula (3-1) or the general formula (3-2) preferably used in the organic EL device of the present invention is showing in FIG. 18 to 19 or 20. The present invention, however, is not restricted to these compounds.

[0116] The triarylamine compounds of the general formula (1) were purified by methods such as column chromatography, adsorption using, for example, a silica gel, activated carbon, or activated clay, recrystallization or crystallization using a solvent, and a sublimation purification method. The compounds were identified by an NMR analysis. A glass transition point (Tg), and a work function were measured as material property values. The glass transition point (Tg) can be used as an index of stability in a thin-film state, and the work function can be used as an index of hole transportability and hole blocking performance. Other compounds used for the organic EL device of the present invention were purified by methods such as column chromatography, adsorption using, for example, a silica gel, activated carbon, or activated clay, and recrystallization or crystallization using a solvent, and finally purified by a sublimation purification method.

[0117] The glass transition point (Tg) was measured by a high-sensitive differential scanning calorimeter (DSC3100SA produced by Bruker AXS) using powder.

[0118] For the measurement of the work function, a 100 nm-thickness thin film was fabricated on an ITO substrate, and an ionization potential measuring device (PYS-202 produced by Sumitomo Heavy Industries, Ltd.) was used.

[0119] The organic EL device of the present invention may have a structure including an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode successively formed on a substrate, optionally with a hole injection layer between the anode and hole transport layer, a hole blocking layer between the light emitting layer and the electron transport layer, and an electron injection layer between the electron transport layer and the cathode. Some of the organic layers in the multilayer structure may be omitted, or may serve more than one function. For example, a single organic layer may serve as the hole injection layer and the hole transport layer, or as the electron injection layer and the electron transport layer, and so on. Further, any of the layers may be configured to laminate two or more organic layers having the same function, and the hole transport layer may have a two-layer laminated structure, the light emitting layer may have a two-layer laminated structure, the electron transport layer may have a two-layer laminated structure, and so on. The organic EL device of the present invention is preferably configured such that the hole transport layer has a two-layer laminated structure of a first hole transport layer and a second hole transport layer. In this case, the second hole transport layer is preferably adjacent to a light emitting layer, and it can function as an electron blocking layer.

[0120] Electrode materials with high work functions such as ITO and gold are used as the anode of the organic EL device of the present invention. The hole injection layer of the organic EL device of the present invention may be made of, for example, material such as starburst-type triphenylamine derivatives and various triphenylamine tetramers; porphyrin compounds as represented by copper phthalocyanine; accepting heterocyclic compounds such as hexacyano azatriphenylene; and coating-type polymer materials. These materials may be formed into a thin film by a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0121] The triarylamine compounds of the general formula (1) are used as the hole transport layer of the organic EL device of the present invention. Examples of a hole transporting material that can be mixed or can be used at the same time with the triarylamine compounds of the general formula (1) can be the organic amine compounds such as various triphenylamine derivatives such as arylamine compounds having a structure in which four triphenylamine structures are joined within a molecule via a single bond or a divalent group that does not contain a heteroatom; and arylamine compounds having a structure in which two triphenylamine structures are joined within a molecule via a single bond or a divalent group that does not contain a heteroatom, in addition to benzidine derivatives such as N,N′-diphenyl-N,N′-di(m-tolyl)benzidine (TPD), N,N′-diphenyl-N,N′-di(α-naphthyl)benzidine (NPD), and N,N,N′,N′-tetrabiphenylylbenzidine; and 1,1-bis[4-(di-4-tolylamino)phenyl]cyclohexane (TAPC). These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer. These materials may be formed into a thin film by a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0122] The material used for the hole injection layer or the hole transport layer may be obtained by p-doping materials such as trisbromophenylamine hexachloroantimony, and radialene derivatives (refer to Patent Document 6, for example) into a material commonly used for these layers, or may be, for example, polymer compounds each having, as a part of the compound structure, a structure of a benzidine derivative such as TPD.

[0123] In the case where the hole transport layer of the organic EL device of the present invention has a two-layer structure of a first hole transport layer and a second hole transport layer, the triarylamine compounds of the general formula (1) are used as the second hole transport layer located on the light emitting layer side. Examples of a hole transporting material that can be mixed or can be used at the same time with the triarylamine compounds of the general formula (1) can be compounds having an electron blocking effect, including, for example, carbazole derivatives such as 4,4′,4″-tri(N-carbazolyl)triphenylamine (TCTA), 9,9-bis[4-(carbazol-9-yl)phenyl]fluorene, 1,3-bis(carbazol yl)benzene (mCP), and 2,2-bis[4-(carbazol yl)phenyl]adamantane (Ad-Cz); and compounds having a triphenylsilyl group and a triarylamine structure, as represented by 9-[4-(carbazol-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene.

[0124] These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer. These materials may be formed into a thin film by using a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0125] Material used for the light emitting layer of the organic EL device of the present invention can be preferably the compounds represented by the general formula (3-1) or the general formula (3-2). Furthermore, various metal complexes in addition to the quinolinol derivative metal complexes such as Alq.sub.3; anthracene derivatives; bis(styryl)benzene derivatives; pyrene derivatives; oxazole derivatives; and polyparaphenylene vinylene derivatives can be used. Further, the light emitting layer may be made of a host material and a dopant material. In that case, as the host material, an anthracene derivative having an anthracene skeleton in the molecule is preferably used. Furthermore, various metal complexes; bis(styryl)benzene derivatives; pyrene derivatives; oxazole derivatives; polyparaphenylene vinylene derivatives; heterocyclic compound having an indole ring as a partial structure of the fused ring; heterocyclic compound having a carbazole ring as a partial structure of fused ring; carbazole derivatives; thiazole derivatives; benzimidazole derivatives; and polydialkylfluorene derivatives can be used. Further, as the dopant material, a compound represented by the general formula (3-1), or the general formula (3-2) is preferably used. Furthermore, a pyrene derivative having a pyrene skeleton in the molecule; heterocyclic compound having an indole ring as a partial structure of the fused ring; heterocyclic compound having a carbazole ring as a partial structure of fused ring; carbazole derivative; thiazole derivative; benzimidazole derivative; polydialkylfluorene derivative; quinacridone, coumarin, rubrene, perylene, derivatives thereof; benzopyran derivative; indenophenanthrene derivatives; rhodamine derivatives; and aminostyryl derivatives can be used. These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer.

[0126] Further, the light-emitting material may be a phosphorescent material. Phosphorescent materials as metal complexes of metals such as iridium and platinum may be used. Examples of the phosphorescent materials include green phosphorescent materials such as Ir(ppy).sub.3, blue phosphorescent materials such as FIrpic and FIr6, and red phosphorescent materials such as Btp.sub.2Ir(acac). Here, an anthracene derivative having an anthracene skeleton in the molecule is preferably used for the host material. Furthermore, carbazole derivatives such as 4,4′-di(N-carbazolyl)biphenyl (CBP), TCTA, and mCP may be used as the hole injecting and transporting host material. Compounds such as p-bis(triphenylsilyl)benzene (UGH2) and 2,2′,2″-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBI) may be used as the electron transporting host material. In this way, a high-performance organic EL device can be produced.

[0127] In order to avoid concentration quenching, the doping of the host material with the phosphorescent light-emitting material should preferably be made by co-evaporation in a range of 1 to 30 weight percent with respect to the whole light emitting layer.

[0128] Further, Examples of the light-emitting material may be delayed fluorescent-emitting material such as a CDCB derivative of PIC-TRZ, CC2TA, PXZ-TRZ, 4CzIPN or the like (refer to Non-Patent Document 3, for example).

[0129] These materials may be formed into a thin film by using a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0130] The hole blocking layer of the organic EL device of the present invention may be formed by using hole blocking compounds such as various rare earth complexes, triazole derivatives, triazine derivatives, and oxadiazole derivatives, in addition to the metal complexes of phenanthroline derivatives such as bathocuproin (BCP), and the metal complexes of quinolinol derivatives such as aluminum(III) bis(2-methyl-8-quinolinate) phenylphenolate (BAlq). These materials may also serve as the material of the electron transport layer. These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer. These materials may be formed into a thin film by using a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0131] The electron transport layer of the organic EL device of the present invention may be formed by using metal complexes of quinolinol derivatives such as Alq.sub.3 and BAlq, various metal complexes, triazole derivatives, triazine derivatives, oxadiazole derivatives, pyridine derivatives, pyrimidine derivatives, benzimidazole derivatives, thiadiazole derivatives, anthracene derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives. These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer. These materials may be formed into a thin film by using a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0132] Examples of material used for the electron injection layer of the organic EL device of the present invention can be alkali metal salts such as lithium fluoride and cesium fluoride; alkaline earth metal salts such as magnesium fluoride; metal complexes of quinolinol derivatives such as lithium quinolinol; metal oxides such as aluminum oxide; and metals such as itterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), cesium (Cs). However, the electron injection layer may be omitted in the preferred selection of the electron transport layer and the cathode.

[0133] Further, in the electron injection layer or the electron transport layer, a material obtained by further N-doping a material which is commonly used for the layer with a metal such as cecium, or the like can be used.

[0134] The cathode of the organic EL device of the present invention may be made of an electrode material with a low work function such as aluminum, or an alloy of an electrode material with an even lower work function such as a magnesium-silver alloy, a magnesium-indium alloy, or an aluminum-magnesium alloy.

[0135] Material used for the capping layer of the organic EL device of the present invention can be preferably arylamine compounds having a structure in which 2 to 6 triphenylamine structures are joined within a molecule via a single bond or a divalent group that does not contain a heteroatom; amine compound having a benzoazole ring structure; or amine compound having an aromatic heterocyclic group in the molecule. These may be individually deposited for film forming, may be used as a single layer deposited mixed with other materials, or may be formed as a laminate of individually deposited layers, a laminate of mixedly deposited layers, or a laminate of the individually deposited layer and the mixedly deposited layer. These materials may be formed into a thin film by using a vapor deposition method or other known methods such as a spin coating method and an inkjet method.

[0136] The following describes an embodiment of the present invention in more detail based on Examples. The present invention, however, is not restricted to the following Examples.

Example 1

Synthesis of bis(4-naphthalen-2-yl-phenyl)-(2′,5′-diphenyl-biphenyl-4-yl)amine (Compound 1-4)

[0137] bis(4-naphthalen-2-yl-phenyl)amine: 10.0 g, 4-bromo-2′,5′-diphenyl-biphenyl: 11.0 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.2 g, tert-butoxy sodium: 2.7 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for 3 hours. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a white powder of bis(4-naphthalen-2-yl-phenyl)-(2′,5′-diphenyl-biphenyl-4-yl)amine (Compound 1-4): 9.0 g (yield: 52.3%) was obtained.

##STR00007##

[0138] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 39 hydrogen signals, as follows, and the structure identified.

[0139] δ (ppm)=8.06 (2H), 7.92 (6H), 7.78 (4H), 7.73 (1H), 7.68 (5H), 7.53 (7H), 7.42 (1H), 7.39-7.23 (9H), 7.14 (4H).

Example 2

Synthesis of (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-phenanthrene-9-yl-amine (Compound 1-58)

[0140] (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)amine: 8.5 g, 9-bromo-phenanthrene: 4.8 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.3 g, tert-butoxy sodium: 2.3 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for 3 hours. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a white powder of (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-1-yl-phenyl)-phenanthrene-9-yl-amine (Compound 1-58): 8.3 g (yield: 73.1%) was obtained.

##STR00008##

[0141] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 37 hydrogen signals, as follows, and the structure identified.

[0142] δ (ppm)=8.79 (1H), 8.75 (1H), 8.14 (1H), 8.03 (1H), 7.92 (1H), 7.85 (2H), 7.72 (6H), 7.65 (2H), 7.60 (1H), 7.50 (7H), 7.42 (1H), 7.36 (3H), 7.27-7.18 (6H), 7.09 (4H).

Example 3

Synthesis of (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-phenanthrene-9-yl-amine (Compound 1-59)

[0143] (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine: 8.0 g, 9-bromo-phenanthrene: 4.5 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.2 g, tert-butoxy sodium: 2.2 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for 3 hours. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a pale yellow powder of (2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-phenanthrene-9-yl-amine (Compound 1-59): 6.6 g (yield: 61.7%) was obtained.

##STR00009##

[0144] .sup.1H-NMR (CDCl.sub.3) of the obtained pale yellow powder detected 37 hydrogen signals, as follows, and the structure identified.

[0145] δ (ppm)=8.79 (1H), 8.74 (1H), 8.09 (1H), 8.01 (1H), 7.86 (4H), 7.75 (1H), 7.71 (5H), 7.66 (2H), 7.60 (3H), 7.50 (5H), 7.39 (1H), 7.34-7.23 (6H), 7.20 (2H), 7.07 (4H).

Example 4

Synthesis of (2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-phenylamine (Compound 1-69)

[0146] (4-naphthalen-2-yl-phenyl)-phenylamine: 6.0 g, 4-bromo-2″,5″-[1,1′;4′,1″]terphenyl: 10.3 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.2 g, tert-butoxy sodium: 2.3 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for overnight. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified using column chromatography (support: silica gel, eluent: dichloromethane/n-heptane), whereby a white powder of (2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)-phenylamine (Compound 1-69): 7.1 g (yield: 51.7%) was obtained.

##STR00010##

[0147] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 37 hydrogen signals, as follows, and the structure identified.

[0148] δ (ppm)=8.04 (1H), 7.91 (3H), 7.73 (5H), 7.66 (2H), 7.56 (2H), 7.51 (7H), 7.42 (1H), 7.39-7.18 (15H), 7.10 (1H).

Example 5

Synthesis of (2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-(4-phenanthrene-9-yl-phenyl)-phenylamine (Compound 1-83)

[0149] (4-phenanthrene-9-yl-phenyl)-phenylamine: 11.0 g, 4-bromo-2″,5″-[1,1′;4′,1″]terphenyl: 16.2 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.3 g, tert-butoxy sodium: 3.7 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for overnight. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified using column chromatography (support: silica gel, eluent: dichloromethane/n-heptane), whereby a white powder of (2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-(4-phenanthrene-9-yl-phenyl)-phenylamine (Compound 1-83): 11.2 g (yield: 48.5%) was obtained.

##STR00011##

[0150] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 39 hydrogen signals, as follows, and the structure identified.

[0151] δ (ppm)=8.81 (1H), 8.75 (1H), 8.09 (1H), 7.93 (1H), 7.71 (7H), 7.65-7.44 (10H), 7.44-7.22 (17H), 7.11 (1H).

Example 6

Synthesis of (2′,5′-diphenyl-biphenyl-4-yl)-(4′-naphthalen-1-yl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine (Compound 1-108)

[0152] 4-bromophenyl-(2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine: 11.0 g, 4-naphthalen-1-yl-phenylboronic acid: 4.8 g, tetrakis(triphenylphosphine)palladium (0): 0.4 g, potassium carbonate: 4.5 g were added into a reaction vessel, and the mixture was stirred at reflux in a mixed solvent of toluene/ethanol/water for overnight. After allowing to cool, a crude product precipitated by adding methanol was collected by filtration. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a white powder of (2′,5′-diphenyl-biphenyl-4-yl)-(4′-naphthalen-1-yl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine (Compound 1-108): 11.0 g (yield: 84.6%) was obtained.

##STR00012##

[0153] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 43 hydrogen signals, as follows, and the structure identified.

[0154] δ (ppm)=8.04 (1H), 7.99 (1H), 7.92 (1H), 7.90 (1H), 7.87 (3H), 7.76 (1H), 7.74-7.69 (5H), 7.65 (3H), 7.61 (2H), 7.57 (2H), 7.54 (1H), 7.53-7.42 (8H), 7.38 (1H), 7.34-7.21 (9H), 7.11 (4H).

Example 7

Synthesis of (2′,5′-diphenyl-biphenyl-4-yl)-(3′-naphthalen-2-yl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine (Compound 1-112)

[0155] 4-bromophenyl-(2′,5′-diphenyl-biphenyl-4-yl)-(4-naphthalen-2-yl-phenyl)amine: 12.0 g, 3-naphthalen-2-yl-phenylboronic acid: 5.3 g, tetrakis(triphenylphosphine)palladium (0): 0.4 g, potassium carbonate: 4.9 g were added into a reaction vessel, and the mixture was stirred at reflux in a mixed solvent of toluene/ethanol/water for overnight. After allowing to cool, a crude product precipitated by adding methanol was collected by filtration. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a white powder of (2′,5′-diphenyl-biphenyl-4-yl)-(3′-naphthalen-2-yl-biphenyl yl)-(4-naphthalen-2-yl-phenyl)amine (Compound 1-112): 11.3 g (yield: 79.7%) was obtained.

##STR00013##

[0156] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 43 hydrogen signals, as follows, and the structure identified.

[0157] δ (ppm)=8.11 (1H), 8.03 (1H), 7.97-7.93 (7H), 7.81 (1H), 7.78-7.57 (10H), 7.57-7.43 (8H), 7.37 (1H), 7.33-7.03 (14H).

Example 8

Synthesis of (9,9-diphenyl-9H-fluorene-2-yl)-(2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-phenylamine (Compound 1-145)

[0158] (2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-phenylamine: 11.0 g, 2-bromo-9,9-diphenyl-9H-fluorene: 10.2 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.2 g, tert-butoxy sodium: 2.7 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for overnight. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified using column chromatography (support: silica gel, eluent: dichloromethane/n-heptane), whereby a white powder of (9,9-diphenyl-9H-fluorene-2-yl)-(2″,5″-diphenyl-[1,1′;4′,1″]terphenyl-4-yl)-phenylamine (Compound 1-145): 15.0 g (yield: 81.9%) was obtained.

##STR00014##

[0159] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 43 hydrogen signals, as follows, and the structure identified.

[0160] δ (ppm)=7.71 (2H), 7.67 (3H), 7.60 (1H), 7.52 (1H), 7.50-7.40 (6H), 7.40-7.30 (3H), 7.27-7.13 (21H), 7.08 (4H), 7.04 (1H), 7.00 (1H).

Example 9

Synthesis of biphenyl-4-yl-(5′-naphthalene-2-yl-[1,1′;2′,1″]terphenyl-4-yl)-([1,1′;4′,1″]terphenyl yl)amine (Compound 1-174)

[0161] biphenyl-4-yl-(5′-naphthalene-2-yl-[1,1′;2′,1″]terphenyl-4-yl)amine: 10.0 g, 4-bromo-[1,1′;4′,1″]terphenyl: 6.5 g, palladium(II) acetate: 0.1 g, tri(tert-butyl)phosphine: 0.2 g, tert-butoxy sodium: 2.2 g were added into a reaction vessel, and the mixture was stirred at reflux in toluene solvent for overnight. After allowing to cool, the filtrate obtained by filtration was concentrated to obtain a crude product. The crude product was purified by crystallization with a mixed solvent of toluene/acetone, whereby a white powder of biphenyl-4-yl-(5′-naphthalene-2-yl-[1,1′;2′,1″]terphenyl-4-yl)-([1,1′;4′,1″]terphenyl yl)amine (Compound 1-174): 10.4 g (yield: 72.4%) was obtained.

##STR00015##

[0162] .sup.1H-NMR (CDCl.sub.3) of the obtained white powder detected 41 hydrogen signals, as follows, and the structure identified.

[0163] δ (ppm)=8.15 (1H), 7.95 (1H), 7.92 (1H), 7.88 (1H), 7.85 (2H), 7.78 (1H), 7.67 (4H), 7.64 (2H), 7.60 (1H), 7.57 (3H), 7.55-7.48 (5H), 7.45 (2H), 7.43 (2H), 7.36 (1H), 7.34-7.26 (6H), 7.20 (4H), 7.15 (2H), 7.07 (2H).

Example 10

Synthesis of Compound (3-1-11)

[0164] 1-bromobenzene (D-substituted): 45.0 g, 4-tert-butylaniline: 58.0 g, palladium (II) acetate: 1.0 g, tert-butoxy sodium: 30.0 g, bis(diphenylphosphino)-1,1′-binaphthyl: 2.0 g, toluene: 450 mL were added into a reaction vessel, and the mixture was refluxed and stirred for 24 hours. After allowing to cool, the mixture was concentrated and purified using column chromatography, whereby a powder of the following compound (3-1-11a): 49.9 g (yield: 78%) was obtained.

##STR00016##

[0165] The above compound (3-1-11a): 20.0 g, the following compound (3-1-11b): 18.4 g, palladium (II) acetate: 0.5 g, tert-butoxy sodium: 18.9 g, tri(tert-butyl)phosphine: 0.8 g, toluene: 200 mL were added into a reaction vessel, and the mixture was refluxed and stirred for 24 hours. After allowing to cool, the mixture was concentrated and purified using column chromatography, whereby a powder of the following compound (3-1-11c): 21.5 g (yield: 84%) was obtained.

##STR00017##

[0166] The above compound (3-1-11c): 12.0 g, and tert-butylbenzene: 120 mL were added into a reaction vessel. Then, 42.5 mL of n-butyllithium was added thereto dropwise at −78° C., and the mixture was aerated with nitrogen gas stirring at 60° C. for 3 hours. Then, 11.3 g of boron tribromid was added thereto dropwise at −78° C., and the mixture was stirred at room temperature for 1 hour. Then, 5.9 g of N, N-diisopropylethylamine was added thereto dropwise at 0° C., and the mixture was stirred at 120° C. for 2 hours. After allowing to cool, an aqueous sodium acetate solution was added thereto, and the mixture is stirred. An organic layer was separated and extracted with ethyl acetate, and the organic layer was concentrated. The mixture was purified using column chromatography, whereby a powder of the following compound (3-1-11): 1.7 g (yield: 11%) was obtained.

##STR00018##

Example 11

[0167] The glass transition points (Tg) of the triarylamine compounds of the general formula (1) were determined using a high-sensitive differential scanning calorimeter (DSC3100SA produced by Bruker AXS). The measurement results are shown below.

TABLE-US-00001 Glass transition point (Tg) Compound of Example 1 107.1° C. Compound of Example 2 131.2° C. Compound of Example 3 129.7° C. Compound of Example 4 110.0° C. Compound of Example 5 127.9° C. Compound of Example 6 121.4° C. Compound of Example 7 109.5° C. Compound of Example 8 136.2° C. Compound of Example 9 116.1° C.

[0168] The triarylamine compounds of the general formula (1) have glass transition points (Tg) of 100° C. or higher, demonstrating that the compounds have a stable thin-film state.

Example 12

[0169] A 100 nm-thick vapor-deposited film was fabricated on an ITO substrate using the triarylamine compounds of the general formula (1), and a work function was measured using an ionization potential measuring device (PYS-202 produced by Sumitomo Heavy Industries, Ltd.). The measurement results are shown below.

TABLE-US-00002 Work function Compound of Example 1 5.67 eV Compound of Example 2 5.72 eV Compound of Example 3 5.75 eV Compound of Example 4 5.72 eV Compound of Example 5 5.76 eV Compound of Example 6 5.69 eV Compound of Example 7 5.69 eV Compound of Example 8 5.68 eV Compound of Example 9 5.69 eV

[0170] As the results show, the triarylamine compounds of the general formula (1) have desirable energy levels compared to the work function 5.4 eV of common hole transport materials such as NPD and TPD, and thus possess desirable hole transportability and an excellent electron blocking ability.

Example 13

[0171] The organic EL device, as shown in FIG. 21, was fabricated by vapor-depositing a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light emitting layer 6, an electron transport layer 7, an electron injection layer 8, a cathode 9 and capping layer 10 in this order on a glass substrate 1 on which an ITO electrode was formed as a transparent anode 2 beforehand.

[0172] Specifically, as the transparent anode 2, an ITO film with a thickness of 50 mm, a silver alloy reflective film with a thickness of 100 nm, and an ITO film with a thickness of 5 nm were deposited on the glass substrate 1 in this order. After ultrasonic cleaning in isopropyl alcohol for 20 minutes, the film was dried on a hot plate heated to 250° C. for 10 minutes. After UV ozone treatment for 15 minutes, the glass substrate with ITO was installed in a vacuum vapor deposition apparatus, and the pressure was reduced to 0.001 Pa or lower. Subsequently, as the hole injection layer 3 covering the transparent anode 2, an electron acceptor (Acceptor-1) of the structural formula below and compound (HTM-1) of the structural formula below were formed in a film thickness of 10 nm by dual vapor deposition at a vapor deposition rate ratio of Acceptor-1:compound (HTM-1)=3:97. The first hole transport layer 4 was formed on the hole injection layer 3 by forming the compounds (HTM-1) of the structural formula below in a film thickness of 140 nm. The second hole transport layer 5 was formed on the first hole transport layer 4 by forming the compound (1-4) of Example 1 in a film thickness of 5 nm. Then, the light emitting layer 6 was formed on the second hole transport layer 5 in a film thickness of 20 nm by dual vapor deposition of the compound (3-1-11) of Example 6 and compound (EMH-1) of the structural formula below at a vapor deposition rate ratio of the compound (3-1-11):compound (EMH-1)=5:95. The electron transport layer 7 was formed on the light emitting layer 6 in a film thickness of 30 nm by dual vapor deposition of the compound (ETM-1) of the structural formula below and compound (ETM-2) of the structural formula below at a vapor deposition rate ratio of the compound (ETM-1):compound (ETM-2)=50:50. The electron injection layer 8 was formed on the electron transport layer 7 by forming lithium fluoride in a film thickness of 1 nm. The cathode 9 was formed on the electron injection layer 8 by forming magnesium silver alloy in a film thickness of 12 nm. Finally, the capping layer 10 was formed by forming the compound (CPL-1) of the structural formula below in a film thickness of 60 nm. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00019## ##STR00020## ##STR00021## ##STR00022##

Example 14

[0173] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-58) of Example 2, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00023##

Example 15

[0174] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-59) of Example 3, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00024##

Example 16

[0175] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-69) of Example 4, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00025##

Example 17

[0176] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-83) of Example 5, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00026##

Example 18

[0177] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-108) of Example 6, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00027##

Example 19

[0178] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-112) of Example 7, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00028##

Example 20

[0179] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-145) of Example 8, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00029##

Example 21

[0180] An organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming the compound (1-174) of Example 9, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00030##

Comparative Example 1

[0181] For comparison, an organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming a compound (HTM-2) of the structural formula below, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00031##

Comparative Example 2

[0182] For comparison, an organic EL device was fabricated under the same conditions used in Example 13, except that the second hole transport layer 5 was formed by forming a compound (HTM-3) of the structural formula below, instead of using the compound (1-4) of Example 1. The emission characteristics of the fabricated organic EL device were measured in the atmosphere at an ordinary temperature by applying a DC voltage. The results are summarized in Table 1.

##STR00032##

[0183] The device lifetime was measured with the organic EL devices fabricated in Examples and Comparative Examples. The results are summarized in Table 1. A device lifetime was measured as the time elapsed until the emission luminance of 2,000 cd/m.sup.2 (initial luminance) at the start of emission was attenuated to 1,900 cd/m.sup.2 (corresponding to attenuation to 95% when taking the initial luminance as 100%) when carrying out constant current driving.

TABLE-US-00003 TABLE 1 Second Device hole (@10 mA/cm.sup.2) lifetime transport Voltage Luminance Luminous Power (Attenuation layer [V] [cd/m.sup.2] efficiency[cd/A] efficiency [lm/W] to 95%) Ex. 13 Compound 3.41 957 9.57 8.83 505 h (1-4) Ex. 14 Compound 3.46 988 9.88 8.97 303 h (1-58) Ex. 15 Compound 3.44 968 9.69 8.85 391 h (1-59) Ex. 16 Compound 3.41 1049 10.49 9.65 601 h (1-69) Ex. 17 Compound 3.46 1017 10.16 9.25 327 h (1-83) Ex. 18 Compound 3.43 1017 10.17 9.33 539 h (1-108) Ex. 19 Compound 3.42 1034 10.34 9.45 645 h (1-112) Ex. 20 Compound 3.45 1052 10.52 9.75 533 h (1-145) Ex. 21 Compound 3.38 980 9.78 9.27 498 h (1-174) Com. HTM-2 3.52 897 8.97 8.19 245 h Ex. 1 Com. HTM-3 3.55 742 7.42 6.75 223 h Ex. 2

[0184] As shown in Table 1, the luminous efficiency upon passing a current with a current density of 10 mA/cm.sup.2 was 9.57 to 10.52 cd/A for the organic EL devices in Examples 13 to 21, which was clearly higher than 7.42 to 8.97 cd/A for the organic EL devices in Comparative Examples 1 and 2. Further, the power efficiency was 8.83 to 9.75 lm/W for the organic EL devices in Examples 13 to 21, which was clearly higher than 6.75 to 8.19 lm/W for the organic EL devices in Comparative Examples 1 and 2. Table 1 also shows that the device lifetime (attenuation to 95%) was 303 to 645 hours for the organic EL devices in Examples 13 to 21, showing achievement of a significantly far longer lifetime than 223 to 245 hours for the organic EL devices in Comparative Examples 1 and 2.

[0185] As is clear from the above results, a triarylamine compound having a specific structure represented by the general formula (1) has a large mobility of holes and has an excellent electron blocking ability compared to the conventional triarylamine compound used in the devices of the comparative examples. Thus, in the organic EL device used together with the material used in the light emitting layer of the present invention, it can be seen that an organic EL device having high luminous efficiency and a long life can be realized as compared with conventional organic EL devices.

INDUSTRIAL APPLICABILITY

[0186] In the organic EL device of the present invention in which a triarylamine compound having a specific structure are used, luminous efficiency and also durability of the organic EL device can be improved compared to conventional organic EL device. Thus, for example, the development of applications in home electric appliances and illuminations can be realized. [0187] 1 Glass substrate [0188] 2 Transparent anode [0189] 3 Hole injection layer [0190] 4 First hole transport layer [0191] 5 Second hole transport layer [0192] 6 Light emitting layer [0193] 7 Electron transport layer [0194] 8 Electron injection layer [0195] 9 Cathode [0196] 10 Capping layer