JP5458890B2 - Organic electroluminescence element, display device and lighting device - Google Patents

Description

  The present invention relates to an organic electroluminescence element, a display device, and a lighting device.

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter referred to as ELD). Examples of constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements).

  Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements. An organic EL device has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, injects electrons and holes into the light emitting layer, and recombines them to generate excitons (exciton). It is an element that emits light by using light emission (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts, and is also self-luminous. In addition, it is attracting attention from the viewpoints of space saving, portability and the like because it is a thin film type complete solid element with a wide viewing angle and high visibility.

  However, in organic EL elements for practical use in the future, development of organic EL elements that emit light efficiently and with high luminance with lower power consumption is desired.

  In Japanese Patent No. 3093796, a small amount of a phosphor is doped into a stilbene derivative, a distyrylarylene derivative or a tristyrylarylene derivative to achieve an improvement in light emission luminance and a longer device lifetime. Further, an element having an organic light-emitting layer in which an 8-hydroxyquinoline aluminum complex is used as a host compound and a small amount of phosphor is doped thereto (for example, JP-A 63-264692), and an 8-hydroxyquinoline aluminum complex is used as a host compound. For example, an element having an organic light emitting layer doped with a quinacridone dye (for example, JP-A-3-255190) is known.

  As described above, when light emission from excited singlet is used, the generation ratio of singlet excitons and triplet excitons is 1: 3, and thus the generation probability of luminescent excited species is 25%. Since the efficiency is about 20%, the limit of the external extraction quantum efficiency (ηext) is set to 5%.

  However, since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet (MA Baldo et al., Nature, 395, 151-154 (1998)), Research on materials that exhibit phosphorescence has become active.

  For example, M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), US Pat. No. 6,097,147, and the like.

  When the excited triplet is used, the upper limit of the internal quantum efficiency is 100%. In principle, the luminous efficiency is four times that of the excited singlet, and there is a possibility that almost the same performance as a cold cathode tube can be obtained. Therefore, it is attracting attention as a lighting application.

  For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), etc., many compounds are being studied for synthesis centering on heavy metal complexes such as iridium complexes.

  In addition, the aforementioned M.I. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), studies have been made using tris (2-phenylpyridine) iridium as a dopant.

In addition, M.M. E. Thompson et al., In The 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), used L ₂ Ir (acac), for example, (ppy) ₂ Ir (acac), e. 0 g, Tetsuo Tsutsui, etc., again The 10th International Workshop on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), the dopant as tris (2-(p-tolyl) pyridine) iridium (Ir (ptpy) _3), tris ( Studies using benzo [h] quinoline) iridium (Ir (bzq) ₃ ) and the like are being conducted (note that these metal complexes are generally called orthometalated iridium complexes).

  In addition, the S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001) and Japanese Patent Application Laid-Open No. 2001-247859, etc., attempts have been made to form devices using various iridium complexes.

  In order to obtain high luminous efficiency, in the 10th International Works on Inorganic and Organic Electroluminescence (EL'00, Hamamatsu), Ikai et al. Uses a hole transporting compound as a host of a phosphorescent compound. In addition, M.M. E. Thompson et al. Use various electron transporting materials as a host of phosphorescent compounds, doped with a novel iridium complex.

  Orthometalated complexes in which the central metal is platinum instead of iridium are also attracting attention. With respect to this type of complex, many examples are known in which ligands are characterized.

  It is also well known to increase the molecular weight and dendrimer of a phosphorescent dopant. In particular, studies have been conducted on phosphorescent dendrimers to suppress the triplet-triplet annihilation and further improve the light emission efficiency (see, for example, Patent Document 1). Dendrimers are huge branched compounds, also called dendritic materials.

However, in order to obtain a high-purity material, a material that is too high in molecular weight and difficult to purify like a polymer is not suitable. Moreover, since high Tg is calculated | required from heat resistant viewpoints, such as a process surface, even if molecular weight is too small, a desirable material cannot be obtained.
JP-T-2005-521210

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic EL element that exhibits high luminous efficiency and has a long light emission lifetime, and further, an illumination device and a display device including the organic EL element. Is to provide.

  The above object of the present invention has been achieved by the following constitution.

1. In an organic electroluminescence device having a light emitting layer sandwiched between an anode and a cathode, the light emitting layer contains a phosphorescent dopant having a molecular weight of 1,000 to 5,000 and a host compound having a molecular weight of 800 to 3,000. The phosphorescent dopant has a partial structure represented by the following general formula (1), and the host compound is a carbazole derivative represented by the following general formula (6), (7) or (8). An organic electroluminescence device characterized by that.
Wherein Y ₁ and Y ₂ represent a carbon atom or a nitrogen atom, Z 1 represents a residue necessary for forming an imidazole ring or a pyrazole ring , and Z 2 forms a benzene ring having no substituent. And M represents iridium .)
(In the formula, Arh represents an aromatic ring group or an aromatic heterocyclic group, and Rn represents an alkyl group, a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, a naphthacene ring, Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, Pyrene ring, pyranthrene ring, anthraanthrene ring, furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, Imidazole ring, pyrazole ring, thiazole ring, Ndole ring, indazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring or diazacarbazole ring. N-Rz, O or S is represented, and Rz represents an alkyl group, an aromatic ring group or an aromatic heterocyclic group.)

2. 2. The organic according to 1 above, wherein Arh in the carbazole derivative represented by the general formula (6), (7) or (8) represents a carbazole ring or a dibenzofuran ring which may have a phenyl group. Electroluminescence element.

3. The organic electroluminescent device according to the 2 the molecular weight of the phosphorescent dopant, and wherein the at 3,000 1,000 or more.

4). The organic electroluminescent device according to the 3 molecular weight of the phosphorescent dopant, and wherein the at 3,000 1,500.

5. The organic electroluminescent device according to the 4 molecular weight of the phosphorescent dopant, and wherein the at 2,500 1,500.

6 . The organic electroluminescent device according to the 5 molecular weight of the host compound, is characterized in that 800 or more 2,000 or less.

7 . The organic electroluminescent device according to the 6 the molecular weight of the host compound, is characterized in that 800 or more 1,500 or less.

8 . The organic electroluminescence device according to 7 above molecular weight of the host compound, characterized in that 1,000 or more 1,500 or less.

9 . Phosphorescent dopant having a partial structure represented by the general formula (1) is any of the 1, characterized in that it comprises a substituent group selected from the following Ki置 substituent group (2) up to 8 The organic electroluminescence device according to one item .

(Arc, the table to an aromatic ring group or an aromatic heterocyclic group. Rm represents an alkyl group, aromatic ring group or an aromatic heterocyclic group.)

1 0 . An organic electroluminescent device comprising an organic layer containing the compound according to any one of 1 to 9 as a constituent layer, wherein the organic layer is formed by a wet process.

1 1 . The organic electroluminescent device according to any one of the above 1, characterized in that white light to 1 0.

1 2 . Display apparatus comprising the organic electroluminescent device according to any one of the items 1 to 1 1.

1 3 . Lighting apparatus comprising the organic electroluminescent device according to any one of the items 1 to 1 1.

  According to the present invention, an organic EL element that exhibits high light emission efficiency and has a long light emission lifetime, and an illumination device and a display device using the element can be provided.

The schematic block diagram of an organic electroluminescent full color display apparatus is shown.

Explanation of symbols

101 Glass substrate 102 ITO transparent electrode 103 Partition 104 Hole injection layer 105B, 105G, 105R Light emitting layer

  In the organic EL device of the present invention, an organic EL device that exhibits high light emission efficiency and has a long light emission lifetime according to the configuration defined in any one of claims 1 to 23, and illumination using the device An apparatus and a display device can be provided.

  Specifically, the organic electroluminescence device of the present invention includes at least one phosphorescent dopant having a molecular weight of 1,000 to 10,000 and a host compound having a molecular weight of 500 to 5,000 in the light emitting layer. It is characterized by containing.

  The phosphorescent dopant according to the present invention has a molecular weight of 1,000 to 10,000, but a molecular weight of 1,000 to 5,000, 1,000 to 3,000, 1,500 to 3, 000 or less is preferable, and a molecular weight of 1,500 to 2,500 is most preferable.

  The host compound according to the present invention has a molecular weight of 500 or more and 5,000 or less, preferably a molecular weight of 800 or more and 3,000 or less, 800 or more and 2,000 or less, and 800 or more and 1,500 or less, and a molecular weight of 1,000. More preferably, it is 1,500 or less.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  In the present invention, the phosphorescent dopant preferably has a partial structure represented by the general formula (1).

  The phosphorescent dopant which is a metal complex having a partial structure represented by the general formula (1) according to the present invention is a structure represented by the general formula (1) or a tautomer of the general formula (1). It is characterized by having at least one of the structures represented (specifically, having as a ligand), and all of the ligands of the metal complex are represented by the general formula (1) A ligand known to those skilled in the art as a so-called ligand which may be composed of only a structure or a structure represented by a tautomer of the general formula (1) and is used for forming a conventionally known metal complex (Also referred to as a coordination compound) may be included as a ligand as necessary.

  From the viewpoint of preferably obtaining the effects described in the present invention, the type of ligand in the complex is preferably composed of 1 to 2 types, and more preferably 1 type.

  There are various known ligands used in conventionally known metal complexes. For example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin, 1987, “Organometallic Chemistry-Fundamentals and Applications-” Liu Huabosha, Akio Yamamoto, published by 1982, etc. (for example, halogen ligands (preferably chlorine ligands), Nitrogen heterocyclic ligands (for example, bipyridyl, phenanthroline, etc.) and diketone ligands).

In the general formula (1), Y ₁ and Y ₂ represent a carbon atom or a nitrogen atom, Z 1 represents a residue necessary for forming an aromatic heterocyclic ring, and Z 2 represents an aromatic ring or an aromatic heterocyclic ring. And M represents a group 8-10 transition metal in the periodic table.

  Examples of the aromatic ring represented by Z2 include benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring. Ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, pyranthrene ring, anthraanthrene ring, etc. It is done. The aromatic ring represented by Z2 is preferably a benzene ring.

  Examples of the aromatic heterocycle represented by Z1 and Z2 include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a benzimidazole ring, an oxadiazole ring, Triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring , A carbazole ring, a carboline ring, a diazacarbazole ring (which represents a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom).

  The aromatic heterocycle represented by Z1 is preferably a pyrazole ring, imidazole ring or pyridine ring, and the aromatic heterocycle represented by Z2 is preferably a 5-membered aromatic heterocycle, such as an oxazole ring or an oxadiazole ring. Oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, isothiazole ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring and the like.

  As the metal M used for forming the metal complex, a transition metal element of Group 8 to 10 (also simply referred to as a transition metal) in the periodic table of elements is used. Among them, iridium is a preferable transition metal element.

  The phosphorescent dopant having a partial structure represented by the general formula (1) preferably has the substituent group (2).

  In the substituent group (2), Arc represents an aromatic ring group or an aromatic heterocyclic group, and Rm represents an alkyl group, an aromatic ring group or an aromatic heterocyclic group. Examples of the aromatic ring group represented by Arc and Rm include groups derived from the aromatic ring listed as Z2 in the general formula (1). Examples of the aromatic heterocyclic group represented by Arc and Rm include those represented by the general formula (1). Examples thereof include groups derived from the aromatic heterocycles mentioned for Z1 and Z2. Examples of the alkyl group represented by Rm include a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, A dodecyl group, a tridecyl group, a tetradecyl group, and a pentadecyl group are mentioned.

  More specifically, the Arc is represented by the general formula (3) or (4).

In the general formula (3), X _{3 to} X ₁₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom, R _{1 to} R ₁₀ represent a hydrogen atom or a substituent, Ar ₂ represents an aromatic ring group, an aromatic group Represents a heterocyclic group, n2 represents an integer of 0 to 10, and R ₅ and R ₆ may be directly bonded to form a ring.

Examples of the aromatic ring group represented by Ar ₂ include groups derived from the aromatic ring listed as Z2 in the general formula (1), and examples of the aromatic heterocyclic group include Z1 and Z2 in the general formula (1). And groups derived from aromatic heterocycles.

Examples of the substituent represented by R _{1 to} R ₁₀ include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group). Group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2 -Pentenyl group, isopropenyl group etc.), alkynyl group (eg ethynyl group, propargyl group etc.), aromatic hydrocarbon group (aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group etc. Phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, a Naphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl) Group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), Phthalazinyl group etc.), heterocyclic group (eg pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group etc.), alkoxy group (eg methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group) Group, dodecyloxy Group), cycloalkoxy group (eg cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, naphthyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group, pentylthio). Group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxy Carbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenyloxycarbonyl group, naphthyl) Oxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, Phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl) Group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy , Ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonyl) Amino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group) Methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbo Group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group) Pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexyl) Sulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), a Alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthyl) Sulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino) Group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pen) Fluorophenyl group), a cyano group, a nitro group, hydroxy group, a mercapto group, a silyl group (e.g., trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, a phenyl diethyl silyl group and the like), a phosphono group, and the like.

In the general formula (4), X _{3 to} X ₁₀ each independently represent a carbon atom, a nitrogen atom or an oxygen atom, R _{1 to} R ₁₀ represent a hydrogen atom or a substituent, and any one of R _{1 to} R ₁₀ is -(Ar ₄ ) _n3- , Ar ₃ and Ar ₄ represent an aromatic ring group and an aromatic heterocyclic group, n3 represents an integer of 0 to 10, and R ₅ and R ₆ are directly bonded to form a ring. May be formed.

Substituents R ₁ to R ₁₀ represents is the same as the substituents that formula (3) R ₁ ~R ₁₀ in represents. Moreover, the aromatic ring group and aromatic heterocyclic group which Ar < ₃ >, Ar < ₄ > represents are synonymous with the aromatic ring group and aromatic heterocyclic group which Ar < ₂ > represents in General formula (3).

  Specific examples of the phosphorescent dopant having the partial structure represented by the general formula (1) are shown below.

  These phosphorescent dopants are described in, for example, Organic Letter, vol. 16, 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. Am. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002) , New Journal of Chemistry. 26, 1171 (2002), Organic Letter, vol. 3, pages 415 to 418 (2006), and further by applying methods such as references described in these documents.

  The host compound according to the present invention is preferably a carbazole derivative, and particularly preferably a carbazole derivative represented by the general formula (6), (7) or (8).

  In the general formula (6), (7) or (8), Arh represents an aromatic ring group or an aromatic heterocyclic group, and Rn represents an alkyl group, an aromatic ring group or an aromatic heterocyclic group. Z represents N—Rz, O, or S, and Rz represents an alkyl group, an aromatic ring group, or an aromatic heterocyclic group.

The aromatic ring group and aromatic heterocyclic group represented by Arh are synonymous with the aromatic ring group and aromatic heterocyclic group represented by Ar ₂ in the general formula (3). The alkyl group, aromatic ring group and aromatic heterocyclic group represented by Rn and Rz have the same meanings as the alkyl group, aromatic ring group and aromatic heterocyclic group represented by Rm in the substituent group (2).

  Moreover, as a host compound which concerns on this invention, the compound represented by the said General formula (9) is also preferable.

In General formula (9), Y < ₁ > and Y < ₂ > represent O, S, or NR < ₀ >, R < ₀ >, R < ₁₁ > -R < ₁₈ > and R < ₂₁ > -R < ₂₈ > represent a hydrogen atom or a substituent. However, at least one of R _{11 to} R ₁₈ and R ₀ is used for connection with X _1, and at least one of R _{21 to} R ₂₈ and R ₀ is used for connection with X ₁ . X ₁ represents a divalent linking group represented by the general formula (10) or (11). n1 represents an integer of 1 or more, and when n1 is 2 or more, X ₁ may be the same or different.

In the general formulas (10) and (11), Y ₃ represents O, S or NR ₃₀ , and R _{30 to} R ₃₈ and R _{41 to} R ₄₆ represent a hydrogen atom or a substituent. However, at least two of each of R _{30 to} R ₃₈ and R _{41 to} R ₄₆ are used for connection, and when R ₄₁ and R ₄₄ are used for connection, R ₄₂ , R ₄₃ , R ₄₅ , R ₄₆ At least one has a substituent other than a hydrogen atom.

The substituents represented by R ₀ , R _{11 to} R ₁₈ and R _{21 to} R ₂₈ , and R _{30 to} R ₃₈ and R _{41 to} R ₄₆ are the same as the substituents represented by R _{1 to} R _{10 in} the general formula (3). It is synonymous.

  Specific examples of the carbazole derivative represented by the general formula (6), (7), or (8), and the compound represented by the general formula (9), which are listed below as host compounds according to the present invention. An example is shown.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode.

  In the organic EL device of the present invention, the blue light emitting layer preferably has an emission maximum wavelength of 430 to 480 nm, the green light emitting layer has an emission maximum wavelength of 510 to 550 nm, and the red light emitting layer has an emission maximum wavelength of 600 to 640 nm. A monochromatic light emitting layer in the range is preferable, and a display device using these is preferable. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

  Each layer which comprises the organic EL element of this invention is demonstrated.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but it is 2 nm to from the viewpoint of preventing the application of a high voltage unnecessary for the film homogeneity and light emission and improving the stability of the emission color with respect to the drive current. It is preferable to adjust to the range of 5 micrometers, More preferably, it adjusts to the range of 2-200 nm, Most preferably, it is the range of 10-20 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. it can.

  The light emitting layer of the organic EL device of the present invention preferably contains a host compound and at least one kind of light emitting dopant (phosphorescent dopant, fluorescent dopant, etc.).

(Host compound)
The host compound used in the present invention will be described.

  Here, the host compound in the present invention is a phosphorescent quantum yield of phosphorescence emission at a room temperature (25 ° C.) having a mass ratio of 20% or more in the compound contained in the light emitting layer. Is defined as a compound of less than 0.1. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  The host compound may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of light emission dopants mentioned later, and, thereby, arbitrary luminescent colors can be obtained.

  The host compound used in the present invention has a molecular weight of 500 or more and 5,000 or less, preferably a carbazole derivative as described above, and further represented by the general formula (6), (7) or (8). A derivative or a compound represented by the general formula (9) is more preferable.

  As a known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.

  Specific examples of known host compounds include compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

(Phosphorescent dopant)
The phosphorescent dopant according to the present invention will be described.

  The phosphorescent dopant according to the present invention is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.) and has a phosphorescence quantum yield. The phosphorescence quantum yield is preferably 0.1 or more, although it is defined as a compound of 0.01 or more at 25 ° C.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence emitting dopant according to the present invention achieves the above phosphorescence quantum yield (0.01 or more) in any solvent. It only has to be done.

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound. The energy transfer type is to obtain light emission from the phosphorescent dopant by transferring to the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, and carrier recombination occurs on the phosphorescent dopant to cause phosphorescence. It is a carrier trap type in which light emission from a light-emitting dopant can be obtained. However, in any case, it is a condition that the excited state energy of the phosphorescent light-emitting dopant is lower than the excited state energy of the host compound. .

  The phosphorescent dopant can be appropriately selected from known materials used for the light emitting layer of the organic EL device.

  The phosphorescent dopant according to the present invention has a molecular weight of 1,000 or more and 10,000 or less, and preferably has a partial structure represented by the general formula (1).

  In the present invention, a known phosphorescent dopant can be used.

  Although the specific example of the compound used as a phosphorescent dopant below is shown, this invention is not limited to these. These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking.

  Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be determined by, for example, the following method.

  (1) Using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), a molecular orbital calculation software manufactured by Gaussian, USA As a result of structural optimization using B3LYP / 6-31G *, the ionization potential can be obtained as a value obtained by rounding off the second decimal place of the calculated value (eV unit converted value). This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

  (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the probability of recombination of electrons and holes can be improved.

  Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transporting layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, and JP-A-2001-102175; Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, when a single electron transport layer and a plurality of layers are used, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transmitting the generated electrons to the light-emitting layer, any material selected from conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone Derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like.

  Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and hole transport layer Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode substances include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like.

  The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the emission luminance is advantageously improved.

  Moreover, after producing the said metal with a film thickness of 1-20 nm on a cathode, a transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
As a support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Polyetherimide, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (JSR Corp.) or APEL (manufactured by Mitsui Chemicals, Inc.).

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24 h) or less, and more preferably oxygen permeability measured by a method according to JIS K 7126-1987. A high barrier property film having a degree of 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  The external extraction quantum efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more.

  Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

  In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned.

Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less, and a method according to JIS K 7129-1992. The measured water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials.

  The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, it is preferable to inject an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil in the gas phase and the liquid phase. . A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used. It is preferable to use a film.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and only 15% to 20% of light generated in the light emitting layer can be extracted. It is generally said that there is no. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode) diffracts light that cannot be emitted outside due to total internal reflection between layers. I want to take it out.

  The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.

  However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the light emitting surface By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, thereby producing an anode.

  Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are organic EL element materials, is formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above, but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is preferable in the present invention.

  Examples of the liquid medium for dissolving or dispersing the compound according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, mesitylene, and cyclohexyl. Aromatic hydrocarbons such as benzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 50 to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the anode as + and the cathode as-polarity. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the device may be patterned. Can do.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with the total CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

Further, when the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 color system at 1000 Cd / m ² is X when the 2-degree viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

<< Production of Organic EL Element 1-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode, this ITO transparent electrode is provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was heated at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 25 nm.

  On this second hole transport layer, a solution prepared by dissolving 100 mg of comparative host 1 and 10 mg of comparative dopant 1 in 10 ml of toluene was formed by spin coating at 1000 rpm for 30 seconds, and then at 60 ° C. It vacuum-dried for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution obtained by dissolving 50 mg of the electron transport material 1 in 10 ml of n-butanol was formed on this light emitting layer by spin coating at 1000 rpm for 30 seconds, and vacuum dried at 60 ° C. for 1 hour. An electron transport layer having a thickness of about 25 nm was obtained.

This is attached to a vacuum deposition apparatus, and then the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, lithium fluoride 1.0 nm is deposited as a cathode buffer layer and aluminum 110 nm is deposited as a cathode to form a cathode, and the organic EL element 1 -1 was produced.

<< Production of Organic EL Elements 1-2 to 1-16 >>
In the production of the organic EL element 1-1, 1-2 to 1-16 were produced by the same method as the organic EL element 1-1 except that the comparative host 1 and the comparative dopant 1 were replaced with the compounds shown in Table 1. In addition, the comparative dopant 2 remove | excluded the component of molecular weight 10,000 or less using the Japan Analytical Industries preparative GPC (LC-9101, column AIGEL-2.5H).

<< Evaluation of organic EL elements >>
The produced organic EL elements 1-1 to 1-16 were evaluated as follows, and the results are shown in Table 1.

(External quantum efficiency)
About the produced organic EL element, the external extraction quantum efficiency (%) when a ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used in the same manner.

  The measurement results of the external extraction quantum efficiency in Table 1 are expressed as relative values when the measurement value of the organic EL element 1-2 is 100.

(lifespan)
When driving at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used.

  The lifetime measurement results in Table 1 are expressed as relative values when the organic EL element 1-2 is set to 1.

  From Table 1, it is clear that the organic EL element of the present invention has higher luminous efficiency and longer emission lifetime than the comparative organic EL element.

Example 2
<< Preparation of Organic EL Element 2-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode, this ITO transparent electrode is provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was heated at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 25 nm.

  On this second hole transport layer, a solution prepared by dissolving 100 mg of comparative host 1 and 10 mg of comparative dopant 3 in 10 ml of toluene was formed by spin coating at 1000 rpm for 30 seconds, and then at 60 ° C. It vacuum-dried for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution obtained by dissolving 50 mg of the electron transport material 1 in 10 ml of n-butanol was formed on this light emitting layer by spin coating at 1000 rpm for 30 seconds, and vacuum dried at 60 ° C. for 1 hour. An electron transport layer having a thickness of about 25 nm was obtained.

This is attached to a vacuum deposition apparatus, and then the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, lithium fluoride 1.0 nm is deposited as a cathode buffer layer and aluminum 110 nm is deposited as a cathode to form a cathode, and the organic EL element 2 -1 was produced.

<< Production of Organic EL Elements 2-2 to 2-24 >>
In the production of the organic EL element 2-1, 2-2 to 2-24 were produced in the same manner as the organic EL element 2-1, except that the comparative host 1 and the comparative dopant 3 were replaced with the compounds shown in Table 2. In addition, the comparative dopant 4 remove | excluded the component of molecular weight 10,000 or less using the Japan Analytical Industries preparative GPC (LC-9101, column AIGEL-2.5H).

<< Evaluation of organic EL elements >>
The produced organic EL elements 2-1 to 2-24 were evaluated as follows, and the results are shown in Table 2.

(External quantum efficiency)
About the produced organic EL element, the external extraction quantum efficiency (%) when a ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. In addition, the spectral radiance meter CS-1000 (made by Konica Minolta) was similarly used for the measurement.

  The measurement results of the external extraction quantum efficiency in Table 2 are expressed as relative values when the measured value of the organic EL element 2-2 is 100.

(lifespan)
When driving at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used.

  The lifetime measurement results in Table 2 are expressed as relative values when the organic EL element 2-2 is 1.

  From Table 2, it is clear that the organic EL element of the present invention has higher luminous efficiency and longer emission lifetime than the comparative organic EL element.

Example 3
<< Production of Organic EL Element 3-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode, this ITO transparent electrode is provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was heated at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. In a nitrogen atmosphere, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking to form a second hole transport layer having a thickness of about 25 nm.

  On this second hole transport layer, a solution prepared by dissolving 100 mg of comparative host 1 and 10 mg of comparative dopant 5 in 10 ml of toluene was formed by spin coating at 1000 rpm for 30 seconds, and then at 60 ° C. It vacuum-dried for 1 hour, and was set as the light emitting layer with a film thickness of about 50 nm.

  Next, a solution of 50 mg of the electron transport material 1 dissolved in 10 ml of n-butanol is formed on this light emitting layer by spin coating at 1000 rpm for 30 seconds, and vacuum dried at 60 ° C. for 1 hour. An electron transport layer having a thickness of about 25 nm was obtained.

This was attached to a vacuum deposition apparatus, and then the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Lithium fluoride 1.0 nm was deposited as a cathode buffer layer and aluminum 110 nm was deposited as a cathode to form a cathode. Organic EL element 3 -1 was produced.

<< Production of Organic EL Elements 3-2 to 3-8 >>
In the production of the organic EL element 3-1, 3-2 to 3-8 were produced in the same manner as the organic EL element 3-1, except that the comparative host 1 and the comparative dopant 5 were replaced with the compounds shown in Table 3. In addition, the comparative dopant 6 remove | excluded the component of molecular weight 10,000 or less using the Japan Analytical Industries preparative GPC (LC-9101, column AIGEL-2.5H).

<< Evaluation of organic EL elements >>
The produced organic EL elements 3-1 to 3-8 were evaluated as follows, and the results are shown in Table 3.

(External quantum efficiency)
About the produced organic EL element, the external extraction quantum efficiency (%) when a ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used in the same manner.

  The measurement results of the external extraction quantum efficiency in Table 3 are expressed as relative values when the measurement value of the organic EL element 3-2 is 100.

(lifespan)
When driving at a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ 0.5). As an index of life. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used.

  The lifetime measurement results in Table 3 are expressed as relative values when the organic EL element 3-2 is set to 1.

  From Table 3, it is clear that the organic EL element of the present invention has higher luminous efficiency and longer emission lifetime than the comparative organic EL element.

Example 4
<< Production of organic EL full-color display device >>
FIG. 1 shows a schematic configuration diagram of an organic EL full-color display device. After patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by forming a 100 nm ITO transparent electrode (102) on a glass substrate 101 as an anode, non-between the ITO transparent electrodes on this glass substrate A photosensitive polyimide partition 103 (width 20 μm, thickness 2.0 μm) was formed by photolithography. A hole injection layer composition having the following composition is ejected and injected between polyimide partition walls on the ITO electrode using an inkjet head (manufactured by Epson Corporation; MJ800C), irradiated with ultraviolet light for 180 seconds, and dried at 60 ° C. for 10 minutes. A hole injection layer 104 having a thickness of 40 nm was produced by the treatment.

  On the hole injection layer, the following blue light-emitting layer composition, green light-emitting layer composition, and red light-emitting layer composition were similarly discharged and injected using an inkjet head, and then dried at 60 ° C. for 10 minutes. Each light emitting layer (105B, 105G, 105R) was formed. Finally, Al (106) was vacuum-deposited as a cathode so as to cover the light emitting layer 105, and an organic EL element was produced.

  It was found that the produced organic EL element exhibited blue, green, and red light emission by applying a voltage to each electrode, and could be used as a full-color display device.

(Hole injection layer composition)
Hole transport material 1 20 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass (Blue light emitting layer composition)
Exemplified Compound 2-6 0.7 parts by mass D-1 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (green light emitting layer composition)
Exemplified Compound 2-6 0.7 parts by mass D-19 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass (red light emitting layer composition)
Example Compound 2-6 0.7 parts by mass D-22 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass Example 5
<< Preparation of white light emitting element and white lighting device >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode, this ITO transparent electrode is provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. After the film formation by spin coating, the film was dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 30 nm.

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 1 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. After irradiating with ultraviolet light for 180 seconds to carry out photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, spin coating method was performed under the conditions of 1000 rpm and 30 seconds using a solution obtained by dissolving Exemplified Compound 2-6 (60 mg), D-1 (3.0 mg), and D-22 (0.3 mg) in 6 ml of toluene. To form a film. Furthermore, it heated at 60 degreeC in vacuum for 1 hour, and was set as the light emitting layer.

  Furthermore, a film in which electron transport material 1 (20 mg) was dissolved in 6 ml of n-butanol was used to form a film by spin coating under conditions of 1000 rpm and 30 seconds. Furthermore, it heated at 60 degreeC in vacuum for 1 hour, and was set as the electron carrying layer.

  Then, this board | substrate was fixed to the substrate holder of a vacuum evaporation system, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the white light emitting organic EL element was produced.

  When this element was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces with the other compound of illustration.

Claims (13)

In an organic electroluminescence device having a light emitting layer sandwiched between an anode and a cathode, the light emitting layer contains a phosphorescent dopant having a molecular weight of 1,000 to 5,000 and a host compound having a molecular weight of 800 to 3,000. The phosphorescent dopant has a partial structure represented by the following general formula (1), and the host compound is a carbazole derivative represented by the following general formula (6), (7) or (8). An organic electroluminescence device characterized by that.
Wherein Y ₁ and Y ₂ represent a carbon atom or a nitrogen atom, Z 1 represents a residue necessary for forming an imidazole ring or a pyrazole ring , and Z 2 forms a benzene ring having no substituent. And M represents iridium .)
(In the formula, Arh represents an aromatic ring group or an aromatic heterocyclic group, and Rn represents an alkyl group, a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, a naphthacene ring, Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, Pyrene ring, pyranthrene ring, anthraanthrene ring, furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, Imidazole ring, pyrazole ring, thiazole ring, Ndole ring, indazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring or diazacarbazole ring. N-Rz, O or S is represented, and Rz represents an alkyl group, an aromatic ring group or an aromatic heterocyclic group.) The Arh in the carbazole derivative represented by the general formula (6), (7) or (8) represents a carbazole ring or a dibenzofuran ring which may have a phenyl group. Organic electroluminescence device. The organic electroluminescence element according to claim 2, wherein the phosphorescent dopant has a molecular weight of 1,000 or more and 3,000 or less. The organic electroluminescence device according to claim 3, wherein the phosphorescent dopant has a molecular weight of 1,500 or more and 3,000 or less. The organic electroluminescence device according to claim 4, wherein the phosphorescent dopant has a molecular weight of 1,500 or more and 2,500 or less. 6. The organic electroluminescence device according to claim 5, wherein the host compound has a molecular weight of 800 or more and 2,000 or less. The organic electroluminescence device according to claim 6, wherein the host compound has a molecular weight of 800 or more and 1,500 or less. The organic electroluminescence device according to claim 7, wherein the host compound has a molecular weight of 1,000 or more and 1,500 or less. The phosphorescent dopant having a partial structure represented by the general formula (1) has a substituent selected from the following substituent group (2). The organic electroluminescent element according to claim 1.
(Arc represents an aromatic ring group or an aromatic heterocyclic group. Rm represents an alkyl group, an aromatic ring group or an aromatic heterocyclic group.) An organic electroluminescent device comprising an organic layer containing the compound according to any one of claims 1 to 9 as a constituent layer, wherein the organic layer is formed by a wet process. The organic electroluminescent device according to any one of claims 1 to 10, characterized in that the white light emission. A display device comprising the organic electroluminescence element according to any one of claims 1 to 11 . An illuminating device comprising the organic electroluminescent element according to any one of claims 1 to 11 .