JP5727237B2 - Novel bicarbazolyl derivative, host material comprising the same, and organic electroluminescence device using the same - Google Patents

Description

  The present invention relates to a novel bicarbazolyl derivative, a host material comprising the same, and an organic electroluminescence device using the same.

Research and development for practical application of organic EL elements (organic electroluminescence elements) is being promoted mainly by domestic and foreign electric manufacturers and material manufacturers. However, in order for this organic EL element to walk like a liquid crystal display element, a light-emitting diode, and other displays that are already known in the world, it is necessary to reduce power consumption and extend the life of the element. ing.
Therefore, in recent years, an organic EL element using a phosphorescent material has been studied for the purpose of solving this problem (Non-Patent Document 1).
Unlike conventional fluorescent materials, phosphorescent materials have a very high quantum efficiency because they can use triplet excited states, and there is almost no energy deactivation, and the internal emission quantum yield reaches almost 100%. .
However, since this phosphorescent material easily causes concentration quenching, it is necessary to use it together with a host material in the same manner as a fluorescent material.
In order to obtain high-efficiency light emission, it is necessary to optimize transport materials and host materials. However, unlike phosphor materials, phosphorescent materials cannot obtain satisfactory effects unless triplet energy is completely confined. Especially for blue materials, the triplet energy level is very high compared to green and red. For this reason, 4,4'-di (N-carbazole) -1,1'-biphenyl (CBP) or the like conventionally used as a host material for phosphorescent materials cannot sufficiently confine energy. Until now, there has been almost no wide-gap host material that can confine this blue phosphorescent energy satisfactorily, which has been one of the factors hindering the development of blue phosphorescent materials.

Appl. Phys. Lett. , 75 (1) 4 (1999)

  An object of the present invention is a host material suitable for a wide-gap phosphorescent material having a high triplet energy level, a novel bicarbazolyl derivative useful for providing a highly efficient light-emitting element, a host material comprising the same, and a It is in the point which provides the used organic electroluminescent element.

The first of the present invention is the following general formula (1)
(Wherein R ^1-4 , R ⁶ and R ⁷ are hydrogen and a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, A linear or branched alkylamino group having 1 to 6 carbon atoms, a cyano group and a group independently selected from the group consisting of fluorine atoms, R ⁵ is hydrogen, an aryl group having 6 to 20 carbon atoms, carbon A linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkylamino group having 1 to 6 carbon atoms, a cyano group, and Ar is a group selected from fluorine atoms, Ar is the following formula
A group selected from the group consisting of a triphenylmethylphenyl group, a diphenylphenyl group and a diphenylphosphoxyphenyl group represented by the ^formula : wherein R ^{20 to 65} are hydrogen, a linear or branched alkyl group having 1 to 4 carbon atoms; , An alkoxy group containing a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkylamino group having 1 to 4 carbon atoms, a trifluoromethyl group, a cyano group, and a fluorine atom, respectively. An independently selected group. )
It relates to the bicarbazolyl derivative shown by these.
The second of the present invention relates to a host material comprising the bicarbazolyl derivative according to claim 1.
A third aspect of the present invention relates to an organic electroluminescence device using the bicarbazolyl derivative according to claim 1.

  According to the present invention, a novel bicarbazolyl derivative, a host material comprising the same, and an organic electroluminescence device using the same can be provided. In order to efficiently emit the blue phosphorescent dopant, a host material having a wide energy gap is required. However, by using the bicarbazolyl derivative of the present invention, an organic EL device with high luminous efficiency can be provided. Therefore, the bicarbazolyl derivative of the present invention is extremely important industrially.

1 shows a ¹ H-NMR chart of 3,3′-bicarbazole of Example 1. FIG. 1 shows a ¹ H-NMR chart of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (2,6-dichloro) benzene (BCzPhCl) in Example 1. FIG. ¹ H-NMR chart (enlarged view) of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (2,6-dichloro) benzene (BCzPhCl) in Example ¹ Indicates. 1 shows a ¹ H-NMR chart of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (2,6-diphenyl) benzene (BCzTP) in Example ¹ . ¹ H-NMR chart (enlarged view) of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (2,6-diphenyl) benzene (BCzTP) in Example ¹ Indicates. The chart of the mass spectrometry (MS) of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (2,6-diphenyl) benzene (BCzTP) in Example 1 is shown. 2 shows a ¹ H-NMR chart of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (diphenylphosphoxy) benzene (BCzPO) in Example 2. The chart (enlarged view) of ¹ H-NMR of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (diphenylphosphoxy) benzene (BCzPO) in Example 2 is shown. . The chart of the mass spectrometry (MS) of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (diphenylphosphoxy) benzene (BCzPO) in Example 2 is shown. The ultraviolet visible absorption spectrum (UV-vis absorption spectrum) of Example 3 is shown. The photoluminescence spectrum (PL spectrum) of Example 4 is shown. The ultraviolet-visible absorption spectrum (UV-vis absorption spectrum) in the solution form (1.0 * 10 < ^-5 > mol / L) of BCzTP of Example 5 is shown. The PL spectrum in the solution state (1.0 * 10 < ^-5 > mol / L) of BCzTP of Example 5 is shown. The ultraviolet visible absorption spectrum (UV-vis absorption spectrum) in the solution form (1.0 * 10 < ^-5 > mol / L) of BCzPO of Example 6 is shown. The PL spectrum in the solution state (1.0 * 10 < ^-5 > mol / L) of BCzPO of Example 6 is shown. The current density-voltage characteristic (linear) of Examples 7 and 8 is shown. The current density-voltage characteristic (logarithm) of Examples 7 and 8 is shown. The luminance-voltage characteristics of Examples 7 and 8 are shown. The current efficiency-voltage characteristics of Examples 7 and 8 are shown. The power efficiency-voltage characteristics of Examples 7 and 8 are shown. The external quantum efficiency-brightness | luminance characteristic of Example 7 and 8 is shown. The organic electroluminescence (EL) spectrum of Examples 7 and 8 is shown. The chart of ¹ H-NMR of 4-iodophenyl-triphenylmethane of Example 9 is shown. The aromatic region enlarged view of 4-iodophenyl-triphenylmethane of Example 9 is shown. The chart of the mass spectrometry (MS) of 4-iodophenyl-triphenylmethane of Example 9 is shown. ¹ shows the ¹ H-NMR chart of 4,4 ′-(3,3′-bi-9H-carbazole) -9,9′-diylbis (1-triphenylmethyl) benzene (BCzTPM) in Example 9. The aromatic region enlarged view of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (1-triphenylmethyl) benzene (BCzTPM) in Example 9 is shown. The chart of the mass spectrometry (MS) of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (1-triphenylmethyl) benzene (BCzTPM) in Example 9 is shown. The UV-vis absorption spectrum of Example 10 is shown. The PL spectrum of Example 10 is shown. The UV-vis absorption spectrum of the vapor deposition film of Examples 11-13 and Reference Example 1 is shown. The PL spectrum of Examples 11-13 and Reference Example 1 is shown. The UV-vis absorption spectrum of the vapor deposition film of Examples 14-16 and the reference example 2 is shown. The PL spectrum of Examples 14-16 and Reference Example 2 is shown. The current density-voltage characteristic (linear) of Examples 17-19 is shown. The current density-voltage characteristic (logarithm) of Examples 17 to 19 is shown. The luminance-voltage characteristic of Examples 17-19 is shown. The current efficiency-voltage characteristic of Examples 17-19 is shown. The power efficiency-voltage characteristic of Examples 17-19 is shown. The external quantum efficiency-luminance characteristic of Examples 17-19 is shown. The electroluminescence (EL) spectrum of Examples 17-19 is shown. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention. It is sectional drawing which shows an example of the organic electroluminescent element in this invention.

As the linear or branched alkyl group having 1 to 6 carbon atoms in R ^{1 to 7} in the present invention, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert- Butyl, n-pentyl, iso-pentyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl and the like can be mentioned. The alkoxy group corresponding to R ^{1 to 7,} for also alkyl the alkyl amino group, can be exemplified the above alkyl.
Furthermore, as the aryl group having 6 to 20 carbon atoms in R ⁵ , phenyl group, 1-naphthyl group, 2-naphthyl group, 4-phenyl-1-naphthyl group, 4-phenyl-2-naphthyl group, 5-phenyl- 1-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 10-phenyl-9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9 -Phenanthryl group, 1-pyrenyl group, 2-pyrenyl group, 2-perylenyl group, 3-perylenyl group, 1-fluoranthenyl group, 2-fluoranthenyl group, 3-fluoranthenyl group, 8-fluoranthenyl Group, 2-triphenylenyl group, 9,9-dimethylfluoren-2-yl group, 9,9-dibutylfluoren-2-yl group, 9,9-dihe Xylfluoren-2-yl group, 9,9-dioctylfluoren-2-yl group, 9,9-diphenylfluoren-2-yl group, 2-biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-tel Phenyl-3-yl group, p-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-4-yl group, o-terphenyl-3-yl group, o-ter Phenyl-4-yl group, 4- (1-naphthyl) -1-naphthyl group, o-tolyl group, m-tolyl group, p-tolyl group, p-tert-butylphenyl group, 4-methoxyphenyl group, 4 -Fluorophenyl group, 4-dimethylaminophenyl group, 4-cyanophenyl group, 4- (trifluoromethyl) phenyl group, 4-methyl-1-naphthyl group, 2-methoxy-1-naphthyl group, 10 Methyl-9-anthryl group, 10-methoxy-9-anthryl group, 4-phenyl-8-fluoranthenyl group, 7-dimethylamino-9,9-dimethylfluoren-2-yl group, 3 ', 5'- A diphenylbiphenyl-4-yl group etc. can be illustrated.
^Examples of the linear or branched alkyl group having 1 to 4 carbon atoms in R ^{20 to 65} include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl and the like. It can be illustrated.

The compound of the present invention can be produced by the following reaction.
Wherein, R ^{1 to 4,} R ⁶ and R ⁷ are hydrogen and straight chain or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, a carbon A linear or branched alkylamino group having 1 to 6 carbon atoms, a cyano group and a group independently selected from the group consisting of fluorine atoms, R ⁵ is hydrogen, an aryl group having 6 to 20 carbon atoms, and a carbon number 1-6 linear or branched alkyl group, alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, linear or branched alkylamino group having 1 to 6 carbon atoms, cyano group and fluorine A group selected from atoms. Ar is the following formula
And a group selected from the group consisting of a triphenylamino group, a diphenylphenyl group, a triphenylsilylphenyl group, a ter-phenyl group, and a diphenylphosphoxyphenyl group represented by the ^formula : R ^{20 to 65} are hydrogen, carbon number 1 -4 linear or branched alkyl groups, or an alkoxy group containing these alkyl groups, an alkylamino group, a trifluoromethyl group, a cyano group, or a group independently selected from the group consisting of fluorine.

  The first reaction is a carbazole dimerization reaction. Anhydrous ferric chloride is used as a reaction catalyst. Regarding the dimerization of carbazole, reaction examples using palladium acetate as a reaction catalyst, for example, I.V. V. Kozhevnikov et al., Reaction Kinetics and Catalysis Letter, 1978, Vol. 9, No. 3, pages 287-290, are not practical because palladium acetate is expensive. Iron chloride also contains hexahydrate, which cannot be used for dimerization reaction.

The second reaction is a reaction between dimerized bicarbazole and ArX. As the solvent used in the second reaction, aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, tetralin, decalin and the like can be used. In consideration of the stability in the reaction system, xylene is preferably used.
As a base used in the reaction system, inorganic salts such as alkali metal and alkaline earth metal hydrates, carbonates and bicarbonates, organic salts such as alkoxides and acetates, and organic alkali compounds such as triethylamine can be used. . In view of reaction time and yield, it is preferable to use carbonate. Even more preferred is potassium carbonate among the carbonates.
As the palladium catalyst used in this reaction, one showing Pd (0) can be used. Specifically, a complex of an organic ligand and palladium can be exemplified. Tetrakis triphenylphosphine palladium and trisdibenzylideneacetone dipalladium are preferable, and trisdibenzylideneacetone dipalladium is more preferable.
A tertiary alkyl phosphine can be used as a phosphorus catalyst to be added to activate palladium. Examples include aliphatic ones such as trimethylphosphine, triethylphosphine, tri [n- (iso-) propyl] phosphine, tri [n- (iso-, tert-) butyl] phosphine, and tricyclohexylphosphine (PCy3). ). In view of compatibility with the palladium compound to be used, alicyclic cyclohexylphosphines such as 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl (S-Phos) are preferred here.

Specific examples of the compound of the present invention are illustrated. In the exemplified compound, the methyl group can be replaced with another alkyl group such as an ethyl group or a propyl group.

  The bicarbazolyl derivative of the present invention has high carrier transport performance. Therefore, it can be used as a host material. In any case, it is desirable to form a layer by vapor deposition.

  When the bicarbazolyl derivative of the present invention is used for organic electroluminescence, it can be used in combination with a suitable light emitting material.

  When the bicarbazolyl derivative of the present invention is used for a light emitting layer, the compound of the present invention can be used as a host material.

  Next, the organic electroluminescence element (organic EL element) of the present invention will be described. The organic EL device of the present invention is a device in which a plurality of layers of organic compounds are laminated between an anode and a cathode, and contains the bicarbazolyl derivative of the present invention as a host material of the light emitting layer. The light emitting layer is composed of a light emitting material and a host material. Examples of the configuration of the multilayer organic EL device include, for example, an anode (for example, ITO) / hole transport layer / light emitting layer / electron transport layer / cathode, ITO / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode. ITO / hole transport layer / light-emitting layer / hole block layer / electron transport layer / cathode, ITO / hole transport layer / light-emitting layer / hole block layer / electron transport layer / electron injection layer / cathode, ITO / hole injection layer (positive And a multilayer structure such as hole injection layer) / hole transport layer / light emitting layer / hole block layer / electron transport layer / electron injection layer / cathode. Moreover, you may have a sealing layer on a cathode as needed.

  Each of the hole transport layer, the electron transport layer, and the light-emitting layer preferably has a multilayer structure in which each function is separated. In addition, the hole transport layer and the electron transport layer can be provided separately with a layer responsible for the injection function (hole injection layer and electron injection layer) and a layer responsible for the transport function (hole transport layer and electron transport layer).

  Hereinafter, the constituent elements of the organic EL element of the present invention will be described by taking as an example an element structure composed of an anode / hole transport layer / light emitting layer / electron transport layer / cathode. The organic EL element of the present invention is preferably supported on a substrate.

  There is no restriction | limiting in particular about the raw material of a board | substrate, For example, what is conventionally used for the conventional organic EL element can be used, For example, what consists of glass, quartz glass, a transparent plastic etc. can be used.

As an anode of the organic EL device of the present invention, it is preferable to use a single metal having a high work function (4 eV or more), an alloy of metals having a high work function (4 eV or more), a conductive substance, or a mixture thereof as an electrode material. . Specific examples of such electrode materials include metals such as gold, silver, and copper, conductive transparent materials such as ITO (indium-tin oxide), tin oxide (SnO ₂ ), and zinc oxide (ZnO), polypyrrole, and polythiophene. Examples thereof include conductive polymer materials such as For the anode, these electrode materials can be formed by a method such as vapor deposition, sputtering, or coating. The sheet electrical resistance of the anode is preferably several hundred Ω / cm ² or less. The thickness of the anode depends on the material, but is generally about 5 to 1,000 nm, preferably 10 to 500 nm.

As the cathode, an electrode material is preferably a single metal having a low work function (4 eV or less), an alloy of metals having a low work function (4 eV or less), a conductive substance, or a mixture thereof. Specific examples of such electrode materials include lithium, lithium-indium alloy, sodium, sodium-potassium alloy, magnesium, magnesium-silver alloy, magnesium-indium alloy, aluminum, aluminum-lithium alloy, and aluminum-magnesium alloy. Can be mentioned. 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 electrical resistance of the cathode is preferably several hundred Ω / cm ² or less. The thickness of the cathode depends on the material, but is generally about 5 to 1,000 nm, preferably 10 to 500 nm. In order to efficiently extract light emitted from the organic EL device of the present invention, at least one of the anode and the cathode is preferably transparent or translucent.

The hole transport layer of the organic electroluminescence element of the present invention is made of a hole transfer compound and has a function of transmitting holes injected from the anode to the light emitting layer. When a hole transfer compound is disposed between two electrodes to which an electric field is applied and holes are injected from the anode, a hole transfer material having a hole mobility of at least 10 ⁻⁶ cm ² / V · sec or more is preferable. The hole transfer material used for the hole transport layer of the organic electroluminescence device of the present invention is not particularly limited as long as it has the above-mentioned preferable performance. Any one of materials conventionally used as charge injection materials for holes in photoconductive materials and known materials used for hole transport layers of organic electroluminescence elements can be selected and used.

Examples of the hole transfer material include phthalocyanine derivatives such as copper phthalocyanine, N, N, N ′, N′-tetraphenyl-1,4-phenylenediamine, N, N′-di (m-tolyl) -N, Triarylamines such as N′-diphenyl-4,4-diaminophenyl (TPD) and N, N′-di (1-naphthyl) -N, N′-diphenyl-4,4-diaminophenyl (α-NPD) Derivatives, polyphenylenediamine derivatives, polythiophene derivatives, and water-soluble PEDOT-PSS (polyethylenedioxathiophene-polystyrene sulfonic acid). The hole transport layer may be composed of one or more of these other hole transport compounds, or may be a stack of hole transport layers composed of a compound different from the hole transport material.
Examples of the hole injection material include PEDOT-PSS (polymer mixture) and DNTPD represented by the following chemical formula.
Examples of the hole transport material include TPD, DTASi, and α-NPD represented by the following chemical formula.

The electron transport layer of the organic electroluminescent element of the present invention is made of an electron transport material and has a function of transmitting electrons injected from the cathode to the light emitting layer. When an electron transport material is arranged between two electrodes to which an electric field is applied and electrons are injected from the cathode, an electron transport material having an electron mobility of at least 10 ⁻⁶ cm ² / V · sec or more is preferable. The electron transport material used for the electron transport layer used in the organic EL device of the present invention is not particularly limited as long as it has the above-mentioned preferable performance. Any one of materials conventionally used as electron charge injection materials in photoconductive materials and known materials used for electron transport layers of organic electroluminescent elements can be selected and used.

Examples of the electron transporting material include quinoline complexes such as tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ), 1-N-phenyl-2- (p-biphenylyl) -5- (p- triazine derivatives such as tert-butylphenyl) -1,3,5-triazine (TAZ), phenanthroline derivatives such as 1,4-di (1,10-phenanthroline-2-yl) benzene (DPB), fluoride Examples include alkali metal halides such as lithium. The electron transport layer may be composed of one or more of these other electron transport materials, and may be a stack of electron transport layers composed of a compound different from the electron transport material. .
Examples of the electron injection material include lithium fluoride (LiF) and 8-hydroxyquinolinolato lithium complex (Liq) represented by the following chemical formula, and Japanese Patent Application Laid-Open No. 2008-106015 (patent document) It is also possible to use a phenanthroline derivative lithium complex (LiPB) related to Japanese Patent Application No. 2006-292032, or a phenoxypyridine lithium complex (LiPP) described in Japanese Patent Application Laid-Open No. 2008-195623 (Japanese Patent Application No. 2007-29695).

Examples of the electron transport material include Alq ₃ , TAZ, and DPB represented by the following chemical formula.

  There is no restriction | limiting in particular about the light emitting material used for the light emitting layer of the organic electroluminescent element of this invention, Arbitrary things can be selected and used.

Examples of the light-emitting material include perylene derivatives, naphthacene derivatives, quinacridone derivatives, coumarin derivatives (eg, coumarin 1, coumarin 540, coumarin 545, etc.), pyran derivatives (eg, DCM-1, DCM-2, DCJTB, etc.), organometallic complexes, such as Fluorescent materials such as tris (8-hydroxyquinolinolato) aluminum complex (Alq ₃ ), tris (4-methyl-8-hydroxyquinolinolato) aluminum complex (Almq ₃ ), and [2- (4,6-difluorophenyl ) Pyridyl-N, C2 ′] iridium (III) picolylate (FIrpic), tris {1- [4- (trifluoromethyl) phenyl] -1H-pyrazolate-N, C2 ′} iridium (III) (Irtfmpppz ₃ ), Bis [2- (4 ', 6'-difluorophenyl) pyridy DOO -N, C2 '] iridium (III) tetrakis (1-pyrazolyl) borate (FIr6), tris (2-phenylpyridinato-) and the like phosphorescent materials such as iridium (III) [Ir _{(ppy) 3]} be able to.

The light emitting layer is formed of a host material and a light emitting material (dopant) [Appl. Phys. Lett. , 65 3610 (1989)]. In particular, when a phosphorescent material is used for the light emitting layer, it is necessary to use a host material, and it is preferable to use the bicarbazolyl derivative of the present invention as the host material used at this time. Other existing host materials 4,4′-di (N-carbazolyl) -1,1′-biphenyl (CBP), 1,4-di (N-carbazolyl) benzene-2,2′-di [4 ″-( N-carbazolyl) phenyl] -1,1′-biphenyl (4CzPBP) and the like can also be used.

The light emitting material is preferably 0.01 to 40% by weight, more preferably 0.1 to 20% by weight with respect to the host material. Examples of the light emitting material include conventionally known FIrpic, Ir (ppy) ₃ , FIr6 and the like shown below.

  In the organic electroluminescence device of the present invention, a hole injection layer composed of an organic conductor may be further provided between the anode and the organic compound layer for the purpose of further improving the hole injection property. Examples of the hole injection material used here include phthalocyanine derivatives such as copper phthalocyanine, polyphenylenediamine derivatives, polythiophene derivatives, and PEDOT-PSS (polyethylenedioxythiophene-polystyrenesulfonic acid) in addition to the compound of the present invention. .

  The method for forming the hole injection layer and the hole transport layer of the device containing the bicarbazolyl derivative of the present invention is not particularly limited. For example, a dry film forming method (for example, a vacuum vapor deposition method, an ionization vapor deposition method, etc.) or a wet film forming method [a solvent coating method (for example, a spin coating method, a casting method, an ink jet method, etc.)] can be used. The film formation of the electron transport layer is limited to a dry film formation method (for example, a vacuum vapor deposition method, an ionization vapor deposition method, etc.) because the lower layer may be eluted when the wet film formation method is used. For the production of the element, the above film forming method may be used in combination.

When forming each layer such as a hole transport layer, a light emitting layer, and an electron transport layer by a vacuum deposition method, the vacuum deposition conditions are not particularly limited. Usually, under a vacuum of about 10 ⁻⁵ torr or less, a boat temperature (deposition source temperature) of about 50 to 500 ° C., a substrate temperature of about −50 to 300 ° C., and 0.01 to 50 nm / sec. Vapor deposition is preferred. When forming each layer of a positive hole transport layer, a light emitting layer, and an electron carrying layer using a some compound, it is preferable to co-evaporate the boat which put the compound, respectively controlling temperature.

  When forming the hole injection layer and the hole transport layer by a solvent coating method, the components constituting each layer are dissolved or dispersed in a solvent to obtain a coating solution. Solvents include hydrocarbon solvents (eg, heptane, toluene, xylene, cyclohexane, etc.), ketone solvents (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), halogen solvents (eg, dichloromethane, chloroform, chlorobenzene, dichlorobenzene, etc.) Ester solvents (eg, ethyl acetate, butyl acetate, etc.), alcohol solvents (eg, methanol, ethanol, butanol, methyl cellosolve, ethyl cellosolve, etc.), ether solvents (eg, dibutyl ether, tetrahydrofuran, 1,4-dioxane, 1 , 2-dimethoxyethane, etc.), aprotic solvents (eg, N, N′-dimethylacetamide, dimethyl sulfoxide, etc.), water and the like. The solvent may be used alone, or a plurality of solvents may be used in combination.

  The thickness of each layer such as a hole transport layer, a light emitting layer, and an electron transport layer is not particularly limited, but is usually set to 5 to 5,000 nm.

  The organic electroluminescence device of the present invention can be protected by providing a protective layer (sealing layer) for the purpose of blocking contact with oxygen, moisture, etc., or by enclosing the device in an inert material. Examples of the inert substance include paraffin, silicon oil, and fluorocarbon. Examples of the material used for the protective layer include fluororesin, epoxy resin, silicone resin, polyester, polycarbonate, and photocurable resin.

  The organic electroluminescence device of the present invention can be used as a normal DC drive device. When a DC voltage is applied, light emission is usually observed when about 1.5 to 20 V is applied with the positive polarity of the anode and the negative polarity of the cathode. The organic EL element of the present invention can also be used as an AC drive element. When an AC voltage is applied, light is emitted when the anode is in a positive state and the cathode is in a negative state. The organic electroluminescence device of the present invention includes, for example, a flat light emitter such as an electrophotographic photosensitive member and a flat panel display, a copying machine, a printer, a backlight of a liquid crystal display, a light source such as an instrument, various light emitting devices, various display devices, and various signs. It can be used for various sensors and various accessories.

  23 to 30 show preferred examples of the organic electroluminescence element of the present invention.

  FIG. 23 is a cross-sectional view showing one example of the organic electroluminescence element of the present invention. FIG. 23 shows a structure in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. This is a separation of the functions of carrier transport and light emission, and the degree of freedom in material selection increases, so that the efficiency of light emission and the degree of freedom in light emission color increase.

  FIG. 24 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 24 shows a structure in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. In this case, the provision of the hole injection layer 7 improves the adhesion between the anode 2 and the hole transport layer 5, improves the injection of holes from the anode, and is effective in lowering the voltage of the light emitting element.

  FIG. 25 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 25 shows a configuration in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8 and a cathode 4 are sequentially provided on a substrate 1. In this case, injection of electrons from the cathode 4 is improved, which is effective for lowering the voltage of the light emitting element.

  FIG. 26 is a cross-sectional view showing another example of the organic electroluminescence element of the present invention. FIG. 26 shows a configuration in which an anode 2, a hole injection layer 7, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6, an electron injection layer 8 and a cathode 4 are sequentially provided on a substrate 1. In this case, hole injection from the anode 2 is improved and electron injection from the cathode 4 is improved, which is the most effective for driving at a low voltage.

  27 to 30 are sectional views of the device in which the hole block layer 9 is inserted. The hole blocking layer 9 has an effect of preventing holes injected from the anode or excitons generated by recombination in the light emitting layer 3 from escaping to the cathode 4, and is effective in improving the light emission efficiency of the organic electroluminescence element. There is. The hole blocking layer 9 can be inserted between the light emitting layer 3 and the cathode 4, between the light emitting layer 3 and the electron transport layer 6, or between the light emitting layer 3 and the electron injection layer 8. More preferred is between the light emitting layer 3 and the electron transport layer 6.

  23 to 30, each of the hole transport layer 5, the hole injection layer 7, the electron transport layer 6, the electron injection layer 8, the light emitting layer 3, and the hole block layer 9 has a single layer structure or a multilayer structure. May be.

  FIGS. 23 to 30 are basic device configurations to the last, and the configuration of the organic electroluminescence device using the compound of the present invention is not limited thereto.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example 1
1) Synthesis of 3,3'-bicarbazole
In a 300 mL eggplant flask, 20 g of iron chloride and 5 g of carbazole were added and stirred vigorously. After confirming the disappearance of carbazole by TLC (thin layer chromatograph), the reaction mixture was added to 2 L of methanol. This operation was performed 10 times and stirred in methanol at room temperature for 22 hours. A green solid was recovered by suction filtration to obtain a dark green solid. The obtained solid was purified by a large sublimation purifier at 1.2 × 10 ⁻² torr, a heating rate of 1 ° C./min, and a sublimation temperature of 250 ° C. to obtain a white solid (yield 2.8 g, yield 11%). ). The target product was identified by ¹ H-NMR (400 MHz, DMSO). A chart of ¹ H-NMR is shown in FIG.

¹ H-NMR (400 MHz, DMSO): δ 11.25 (s, 2H), 8.48 (s, 2H), 8.21 (d, 2H, J = 7.8 Hz), 7.79 (dd, 2H) , J = 1.1, 8.5 Hz), 7.55 (d, 2H, J = 8.7 Hz), 7.48 (d, 2H, J = 8.2 Hz), 7.37 (t, 2H, J = 7.6 Hz), 7.15 (t, 2H, J = 7.6 Hz) ppm.

2) Synthesis of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (2,6-dichloro) benzene (BCzPhCl)

Put 3,3'-bicarbazole, 1-bromo-3,5-dichlorobenzene, copper powder, potassium carbonate, nitrobenzene into a 20 mL eggplant flask, perform nitrogen bubbling for 1 hour, and stir at 170 ° C. for 17 hours under a nitrogen stream. did. The progress of the reaction was confirmed by TLC (ethyl acetate: hexane = 1: 3), the disappearance of 3,3′-bicarbazole was confirmed, and the mixture was cooled to room temperature. The reaction mixture was dissolved in chloroform, and the insoluble material was filtered through celite. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (chloroform: hexane = 1: 1) to obtain a pale yellow solid of BCzPhCl (yield: 810 mg, yield: 54%). They were identified by mass spectrometry (MS) and ¹ H-NMR. ^{A 1} H-NMR chart is shown in FIG. 2, and an enlarged view thereof is shown in FIG. Table 1 shows the preparation conditions for this synthesis. A similar experiment was performed using Run No. 1 in Table 1. It is shown in 2.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.42 (d, 2H, J = 1.36 Hz), 8.42 (d, 2H, J = 7.76 Hz), 7.79 (dd, 2H, J = 7.60, 1.84) 7.56-7.46 (m, 12H), 7.37-7.34 (m, 2H) MS: m / z 622 [M] ^<+> .

3) Synthesis of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (2,6-diphenyl) benzene (BCzTP)

BCzPhCl, phenylboronic acid, toluene, and potassium phosphate were placed in a 50 mL three-necked flask and subjected to nitrogen bubbling for 1 hour. Pd (OAc) ₂ and S-Phos (2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl) were added and refluxed for 20 hours. The progress of the reaction was confirmed by TLC (chloroform: hexane = 1: 2). However, since the reaction was completed with the 3-substituent, nitrogen bubbling was performed again for 1 hour, phenylboronic acid, Pd (OAc) ₂ , S-Phos. And refluxed for 22 hours. The progress of the reaction was confirmed by TLC and cooled to room temperature. The reaction mixture was dissolved in chloroform, the insoluble matter was filtered through Celite, washed with saturated brine, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (chloroform: hexane = 1: 2) to obtain a white solid. Obtained (yield: 300 mg, yield: 38%). They were identified by mass spectrometry (MS) and ¹ H-NMR. FIG. 4 shows a ¹ H-NMR chart, FIG. 5 shows an enlarged view thereof, and FIG. 6 shows a chart of mass spectrometry (MS). Table 2 shows preparation conditions for the synthesis. A similar experiment was performed using Run No. It is shown in 2.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.49 (d, 2H, J = 1.84 Hz), 8.42 (d, 2H, J = 8.27 Hz), 7.92-7.32 (m , 36H) Mass spectrometry (MS): m / z 789 [M] ⁺ . Calculated for elemental analysis _{C 60 H 40 N 2: C} , 91.34; H, 5.11; N, 3.55%. Found: C, 91.40; H, 5.09; N, 3.56%.

4) Sublimation purification of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (2,6-diphenyl) benzene (BCzTP) Charge: 1.0 g, high temperature part: Temperature increase was started at 395 ° C., low temperature part: 190 ° C., N ₂ flow rate: 70 mL / min. A transparent green solid was obtained by heating for 24 hours and sublimation purification (yield: 780 mg, yield: 78%).

Example 2
1) Synthesis of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (diphenylphosphoxy) benzene (BCzPO)
Place 0.56 g of 3,3′-bicarbazole, 1.46 g of 4- (diphenylphosphooxy) bromobenzene, 0.23 g of L-proline, 1.93 g of potassium carbonate and 7 mL of dimethyl sulfoxide in a 20 mL eggplant flask and stir. Then, nitrogen bubbling was performed for 1 hour. After adding 0.21 g of copper iodide, the mixture was stirred at 140 ° C. under a nitrogen stream for 20 hours. After confirming the disappearance of 3,3′-bicarbazole by TLC, the mixture was cooled to room temperature, the reaction mixture was dissolved in chloroform, the insoluble material was filtered, and washed with saturated brine. After dehydration with magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (ethyl acetate: triethylamine = 100: 1) to obtain a yellowish white solid of BCzPO. The target product was identified by thin layer chromatography, mass spectrometry (MS), and ¹ H-NMR. FIG. 7 shows a ¹ H-NMR chart, FIG. 8 shows an enlarged view thereof, and FIG. 9 shows a chart of mass spectrometry (MS). Table 3 shows the charging conditions for this synthesis.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.43 (s, 2H), 8.23 (d, 2H, J = 7.32 Hz), 7.95-7.42 (m, 34H), 7. 8 (t, 1 H, 7.3 Hz), 7, 25 (s, 4 H) ppm. Mass spectrometry (MS): m / z = 885 [M] ⁺ .

2) Sublimation purification of 4,4 '-[3,3'-bi-9H-carbazole] -9,9'-diylbis [diphenylphosphoxy] benzene (BCzPO)

High temperature part: 390 ° C., low temperature part: 200 ° C., N ₂ flow rate: 50 mL / min, charge amount: 400 mg, temperature increase was started. After 19 hours, the high temperature portion was raised by 10 ° C., and after 5 hours, the high temperature portion was raised by 5 ° C. Finally, the mixture was heated at a high temperature part: 405 ° C. for 23 hours for purification by sublimation. (Yield 150 mg, 38% yield)

Examples 3 and 4
The UV-visible absorption spectrum (UV-vis absorption spectrum) and photoluminescence spectrum (PL spectrum) of the vapor-deposited film (quartz substrate, film thickness 500 mm) of BCzTP synthesized in Example 1 and BCzPO synthesized in Example 2 were measured. . FIG. 10 shows a UV-vis absorption spectrum and FIG. 11 shows a PL spectrum of each deposited film.

Example 5
A UV-visible absorption spectrum (UV-vis absorption spectrum) and a photoluminescence spectrum (PL spectrum) of BCzTP synthesized in Example 1 in a solution state (1.0 × 10 ⁻⁵ mol / L) were measured. The UV-vis absorption spectrum is shown in FIG. 12, and the PL spectrum is shown in FIG. In the figure, CHCl ₃ represents chloroform, THF represents tetrahydrofuran, and toluene represents toluene.

Example 6
The UV-visible absorption spectrum (UV-vis absorption spectrum) and photoluminescence spectrum (PL spectrum) of BCzPO synthesized in Example 2 in the form of a solution (1.0 × 10 ⁻⁵ mol / L) were measured. The UV-vis absorption spectrum is shown in FIG. 14, and the PL spectrum is shown in FIG. In the figure, CHCl ₃ represents chloroform, THF represents tetrahydrofuran, and toluene represents toluene.

Examples 7 and 8
Elements using BCzTP synthesized in Example 1 and BCzPO synthesized in Example 2 as host materials were prepared, and the characteristics of each element were evaluated.

The configuration of each element is as follows.
Example 7: [ITO (anode) / TAPC (hole transport layer 40 nm) / BCzTP (host material) FIrpic (11 wt% doped luminescent material with respect to host) (also luminescent layer 10 nm) / BmPyPB (electron transport layer 50 nm) ) / LiF (electron injection layer 0.5 nm) / Al (cathode 100 nm)]
Example 8: [ITO (anode) / TAPC (hole transport layer 40 nm) / BCzPO (host material) FIrpic (11 wt% doped light emitting material with respect to host) (light emitting layer is composed of these host material and light emitting material, 10 nm ) / BmPyPB (electron transport layer 50 nm) / LiF (electron injection layer 0.5 nm) / Al (cathode 100 nm)]
The current density-voltage characteristic (linear) is shown in FIG.
The current density-voltage characteristic (logarithm) is shown in FIG.
The luminance-voltage characteristics are shown in FIG.
The current efficiency vs. voltage characteristics are shown in FIG.
The power efficiency vs. voltage characteristics are shown in FIG.
The external quantum efficiency-luminance characteristics are shown in FIG.
The electroluminescence (EL) spectrum is shown in FIG.
Each is shown.
Table 4 below shows the voltage, power efficiency, and current efficiency of 100 cd / cm ² and 1000 cd / cm ² .

Example 9
1) Synthesis of 4-iodophenyl-triphenylmethane

4-tritylaniline (2.5 g, 7.45 mmol), acetone (70 mL), hydrochloric acid (17 mL, 12%) were dissolved in a 100 mL eggplant flask, cooled to 0 ° C., and then sodium nitrite aqueous solution (5 mL, 0.45M) was added slowly. The reaction solution was then stirred at 0 ° C. for 30 minutes, and then an aqueous potassium iodide solution (7 mL, 0.57 M) was slowly added. Subsequently, the reaction solution was stirred at 0 ° C. for 30 minutes, further stirred at room temperature for 1 hour, further stirred at 60 ° C. for 18 hours, and disappearance of raw materials was confirmed by TLC. Next, the mixture was extracted and washed with an aqueous sodium thiosulfate solution, chloroform and saturated brine, dehydrated over anhydrous magnesium sulfate and filtered, and the solvent was distilled off under reduced pressure. Purification by recrystallization using toluene gave a pale yellow solid. The target product was identified by TLC, mass spectrometry (MS), and ¹ H-NMR (400 MHz, DMSO). A chart of ¹ H-NMR is shown in FIG. 23, an enlarged view of the aromatic region is shown in FIG. 24, and a chart of mass spectrometry (MS) is shown in FIG.
¹ H-NMR (400 MHz, DMSO): δ 7.63 (d, 2H, J = 8.0 Hz), 7.29-7.09 (m, 15H), 6.91 (d, 2H, J = 8. 0 Hz) ppm, MS: m / z = 446 [M] ⁺ .

2) Synthesis of 4,4 '-(3,3'-bi-9H-carbazole) -9,9'-diylbis (1-triphenylmethyl) benzene (BCzTPM)
To a 50 mL three-necked flask, 3,3′-bicarbazole (1.33 g, 4 mmol), 4-iodophenyltriphenylmethane (3.6 g, 8 mmol), L-proline (0.46 g, 4 mmol), carbonic acid Potassium (6.63 g, 48 mmol) and DMSO (20 mL) were added, and nitrogen bubbling was performed for 1 hour. Next, CuI (0.3 g, 1.6 mmol) was added, the mixture was stirred at 140 ° C. for 18 hours under a nitrogen stream, and the progress of the reaction was confirmed by TLC. The reaction mixture was then cooled to room temperature, dissolved in chloroform, and washed with saturated brine. After dehydration with magnesium sulfate, the solvent was distilled off under reduced pressure, and silica gel column chromatography (hexane = 100 => ethyl acetate: hexane = 1: 10 => ethyl acetate: hexane = 1: 5 => ethyl acetate = 100). Purification gave a pale yellow solid (yield: 1.3 g, yield: 33%). FIG. 26 shows a ¹ H-NMR chart, FIG. 27 shows an enlarged view of the aromatic region, and FIG. 28 shows a mass analysis (MS) chart.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.43 (d, 2H, J = 1.4 Hz), 8.22 (d, 2H, 7.8 Hz), 7.76 (dd, 2H, J = 8) .76 Hz, 1.76 Hz), 7.56-7.41 (m, 14H), 7.35-7.25 (m, 32H) ppm. MS (EI): m / z = 970 [M] ⁺ . Anal. _{Calcd for C 74 H 52 N 2} : C, 91.70; H, 5.41; N, 2.89%. Found: C, 91.60; H, 5.55; N, 2.78%.

3) Sublimation purification of BCzTPM Decomposition temperature: 500 ° C., sublimation temperature: estimated to be 351 ° C., sublimation purification was started at a high temperature part: 350 ° C., a low temperature part: 175 ° C., and an N ₂ flow rate: 70 mL / min. The temperature of the high temperature part was raised by 5 ° C. every hour and sublimation purification was performed by heating at 395 ° C. for 24 hours to obtain a white solid.

4) HPLC (High Performance Liquid Chromatography) Purity Measurement of BCzTPM Purity measurement was performed using THF: MeOH = 1: 5 as a developing solvent, and it was confirmed that the purity was 99.2% every 10 minutes.

Example 10
It was measured ultraviolet-visible absorption spectrum (UV-vis absorption spectra) and photoluminescence spectra (PL spectrum) of a solution like BCzTPM synthesized in Example ^{9 (1.0 × 10 -5 mol /} L). The UV-vis absorption spectrum is shown in FIG. 29, and the PL spectrum is shown in FIG. In the figure, CHCl ₃ represents chloroform, THF represents tetrahydrofuran, and toluene represents toluene.

Examples 11-13, Reference Example 1
With the deposited films (quartz substrate, thickness of 500 mm) of BCzTP (Example 11), BCzPO (Example 12), BCzTPM (Example 13) and BCzTPA (Reference Example 1) synthesized in Examples 1, 2, and 9, respectively. Were measured for UV-visible absorption spectrum (UV-vis absorption spectrum) and photoluminescence spectrum (PL spectrum). FIG. 31 shows a UV-vis absorption spectrum and FIG. 32 shows a PL spectrum of each deposited film. The BCzTPA is the following compound described in JP-A No. 2008-135498.

Examples 14-16, Reference Example 2
Deposition films (quartz) doped with 11 weight percent FIrpic in BCzTP (Example 14), BCzPO (Example 15), BCzTPM (Example 16) and BCzTPA (Reference Example 2) synthesized in Examples 1, 2, and 9, respectively. A substrate and a film thickness of 500 mm were prepared, and an ultraviolet-visible absorption spectrum (UV-vis absorption spectrum) and a photoluminescence (PL spectrum) were measured. FIG. 33 shows the UV-vis absorption spectrum of each of the deposited films, and FIG. 34 shows the PL spectrum.
Table 5 summarizes the thermal, optical and electronic properties of the three compounds BCzTP, BCzPO, BCzTP and BCzTPA synthesized this time.

Td: decomposition temperature,
Td5: 5% weight loss temperature,
Tg: glass transition temperature,
Tm: melting point,
Ip: ionization potential,
Eg: energy gap,
Ea: Electroaffinity (electron affinity),
n. d. : Not detected.
About Tg (glass transition temperature), a sample is added to DSC (Differential Scanning Calorimeter), the melted material is quenched, and a curve showing the glass point appears on the chart when repeated 2 to 3 times. The curves are connected by a tangent line, and the temperature at the intersection is adopted as Tg.
As for Tm (melting point), when a sample is similarly added to DSC and the temperature is raised, a rapid heating curve appears. Therefore, the temperature at the maximum is read, and the temperature is defined as Tm.
As for Td (decomposition temperature), when a sample is added to DTA (Differential Thermal Analyzer differential thermal analyzer) and heated, the sample is decomposed by heat and the weight starts to decrease. The temperature at which the decrease starts and the weight decreased by 5% is read, and that point is defined as Td.
Td5 (5% weight loss temperature) is a sample of TG-DTA (Thermo Gravimetry-Differential Thermal Analyzer differential thermal-thermogravimetry), and when heated, the sample decomposes by heat and begins to lose weight. . The temperature at which the decrease starts and the weight decreased by 5% is read, and that point is defined as Td5.
Regarding the energy gap (Eg), an absorption curve of the thin film prepared with a vapor deposition machine is measured with an ultraviolet-visible absorptiometer. A tangent line is drawn at the short-wavelength rising edge of the thin film, and the target wavelength is obtained by substituting the obtained wavelength W (nm) of the intersection into the following equation. The value obtained thereby becomes Eg.
Eg = 1240 ÷ W
For example, if the value W (nm) obtained by drawing the tangent is 470 nm, the value of Eg at this time is
Eg = 1240 ÷ 470 = 2.63 (eV)
It will be said.
IP (ionization potential) is measured using an ionization potential measuring device (for example, Riken Keiki AC-3), and the value of the voltage (eV) at which the sample to be measured starts ionization is read.
Ea (electron affinity) is a value obtained by subtracting Eg from Ip.

Examples 17-19
Devices using BCzTP (Example 17), BCzPO (Example 18), BCzTPM (Example 19) and BCzTPA (Reference Example 3) synthesized in Examples 1, 2, and 9 as host materials were prepared, respectively. The device characteristics were evaluated.
The configuration of each element is as follows.
Example 17: [ITO (anode) / TAPC (hole transport layer 40 nm) / BCzTP (host material) FIrpic (11 wt% doped light emitting material with respect to host) (also light emitting layer 10 nm) / BmPyPB (electron transport layer 50 nm) ) / LiF (electron injection layer 0.5 nm) / Al (cathode 100 nm)]
Example 18: [ITO (anode) / TAPC (hole transport layer 40 nm) / BCzPO (host material) FIrpic (11 wt% doped light emitting material with respect to host) (also light emitting layer 10 nm) / BmPyPB (electron transport layer 50 nm) ) / LiF (electron injection layer 0.5 nm) / Al (cathode 100 nm)]
Example 19: [ITO (anode) / TAPC (hole transport layer 40 nm) / BCzTPM (host material) FIrpic (11 wt% doped luminescent material with respect to host) (also luminescent layer 10 nm) / BmPyPB (electron transport layer 50 nm) ) / LiF (electron injection layer 0.5 nm) / Al (cathode 100 nm)]

The current density-voltage characteristic (linear) is shown in FIG.
The current density-voltage characteristic (logarithm) is shown in FIG.
The luminance-voltage characteristics are shown in FIG.
The current efficiency vs. voltage characteristics are shown in FIG.
The power efficiency vs. voltage characteristics are shown in FIG.
The external quantum efficiency-luminance characteristics are shown in FIG.
The electroluminescence (EL) spectrum is shown in FIG.
Each is shown.
The device characteristics are summarized in Table 6 below. “PE” in the table is power efficiency (visual efficiency).
“Nit” is synonymous with “cd / m ² ”.

1 Substrate 2 Anode (ITO)
DESCRIPTION OF SYMBOLS 3 Light emitting layer 4 Cathode 5 Hole (hole) transport layer 6 Electron transport layer 7 Hole (hole) injection layer 8 Electron injection layer 9 Hole block layer

Claims (3)

The following general formula (1)
(Wherein R ^1-4 , R ⁶ and R ⁷ are hydrogen and a linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, A linear or branched alkylamino group having 1 to 6 carbon atoms, a cyano group and a group independently selected from the group consisting of fluorine atoms, R ⁵ is hydrogen, an aryl group having 6 to 20 carbon atoms, carbon A linear or branched alkyl group having 1 to 6 carbon atoms, an alkoxy group containing a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkylamino group having 1 to 6 carbon atoms, a cyano group, and Ar is a group selected from fluorine atoms, Ar is the following formula
A group selected from the group consisting of a triphenylmethylphenyl group, a diphenylphenyl group and a diphenylphosphoxyphenyl group represented by the ^formula : wherein R ^{20 to 65} are hydrogen, a linear or branched alkyl group having 1 to 4 carbon atoms; , An alkoxy group containing a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkylamino group having 1 to 4 carbon atoms, a trifluoromethyl group, a cyano group, and a fluorine atom, respectively. An independently selected group. )
A bicarbazolyl derivative represented by   A host material comprising the bicarbazolyl derivative according to claim 1.   An organic electroluminescence device using the bicarbazolyl derivative according to claim 1.