JP4600288B2 - ORGANIC ELECTROLUMINESCENT ELEMENT MATERIAL, ORGANIC ELECTROLUMINESCENT ELEMENT, LIGHTING DEVICE AND DISPLAY DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element, an illuminating device, and a display device, and particularly relates to an organic electroluminescent element, an illuminating device, and a display device having the same that are excellent in light emission luminance, luminous efficiency, and durability.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of the 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.

  On the other hand, an organic EL element has a structure in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode. By injecting electrons and holes into the light emitting layer and recombining them, excitons (exciton) are obtained. And emits light using the emission of light (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Since it is a light-emitting type, it has a wide viewing angle, high visibility, and since it is a thin-film type complete solid-state device, it has attracted attention from the viewpoints of space saving and portability.

  For the development of organic EL elements for practical use in the future, organic EL elements that emit light efficiently and with high brightness with lower power consumption are desired. For example, stilbene derivatives, distyrylarylene derivatives, or tris A technique for doping a styrylarylene derivative with a small amount of a phosphor to improve emission luminance and extend the lifetime of the device (see, for example, Patent Document 1), and 8-hydroxyquinoline aluminum complex as a host compound. A device having an organic light-emitting layer doped with a trace amount of phosphor (for example, see Patent Document 2), a device having an organic light-emitting layer doped with a quinacridone dye as a host compound using 8-hydroxyquinoline aluminum complex (for example, , See Patent Document 3).

  In the technique disclosed in the above-mentioned patent document, when the emission from the excited singlet is used, the generation ratio of the singlet exciton and the triplet exciton is 1: 3, so the generation probability of the luminescent excited species is 25%. Since the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (ηext) is set to 5%.

  However, since Princeton University has reported on organic EL devices that use phosphorescence emission from excited triplets (see, for example, Non-Patent Document 1), research on materials that exhibit phosphorescence at room temperature has become active. (For example, see Non-Patent Document 2 and Patent Document 4.)

  When excited triplets are used, the upper limit of internal quantum efficiency is 100%, so in principle the luminous efficiency is four times that of excited singlets, and the performance is almost the same as that of cold cathode tubes. It can be applied to and attracts attention.

  For example, many compounds have been studied focusing on heavy metal complexes such as iridium complexes (see, for example, Non-Patent Document 3).

  Further, studies using tris (2-phenylpyridine) iridium as a dopant have been made (for example, see Non-Patent Document 2).

In addition, L ₂ Ir (acac), for example, (ppy) ₂ Ir (acac) (see, for example, Non-Patent Document 4) as a dopant, and tris (2- (p-tolyl) pyridine) iridium (as a dopant) Studies using Ir (ptpy) ₃ ), tris (benzo [h] quinoline) iridium (Ir (bzq) ₃ ), Ir (bzq) ₂ ClP (Bu) _3, etc. (see, for example, Non-Patent Document 5). Has been done.

  In order to obtain high luminous efficiency, a hole transporting compound is used as a host of the phosphorescent compound (see, for example, Non-Patent Document 6).

  Further, various electron transporting materials are used as phosphorescent compound hosts by doping them with a novel iridium complex (for example, see Non-Patent Document 4). Furthermore, high luminous efficiency is obtained by introducing a hole blocking layer (see, for example, Non-Patent Document 5).

  Currently, further improvement in light emission efficiency and life of organic EL elements using phosphorescence emission are being studied.

  However, although the external extraction efficiency of 20%, which is the theoretical limit for green light emission, has been achieved, it is only in the low current region (low luminance region), and the theoretical limit is still in the high current region (high luminance region). Not achieved. Furthermore, sufficient efficiency has not yet been obtained for other luminescent colors, and improvements are required. In addition, organic EL devices for practical application in the future will emit light efficiently and with high brightness. Development of the organic EL element which does is desired. In particular, there is a demand for an element that emits light with high efficiency in an organic EL element that emits blue phosphorescence.

  As a phosphorescent organic EL device that solves these problems, it is described that a compound containing a boron atom in a molecule is used as a light emitting material or an electron transporting material (for example, see Patent Document 5). There is a need for improved luminous efficiency and luminous lifetime.

Moreover, although the organic EL element containing the boron complex of 8-hydroxyquinoline derivative is described (for example, refer patent document 6), the boron compound was unstable and the further life extension was requested | required.
Japanese Patent No. 3093796 Japanese Unexamined Patent Publication No. 63-264692 JP-A-3-255190 US Pat. No. 6,097,147 JP 2003-234192 A JP 2000-150163 A M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001) M.M. E. Thompson et al. , The 10th International Works on Organic and Organic Electroluminescence (EL'00, Hamamatsu) Moon-Jae Youn. 0 g, Tetsuo Tsutsui et al. , The 10th International Works on Organic and Organic Electroluminescence (EL'00, Hamamatsu) Ikai et al. , The 10th International Works on Organic and Organic Electroluminescence (EL'00, Hamamatsu)

  This invention is made | formed in view of the subject which concerns, and the objective of this invention is the organic EL element material from which luminous efficiency becomes high, the organic EL element using this organic EL element material, an illuminating device, and a display apparatus. Is to provide. Furthermore, it is providing the organic EL element material which becomes long life, the organic EL element using this organic EL element material, an illuminating device, and a display apparatus.

  One aspect for achieving the above object of the present invention is an organic electroluminescent element material characterized by containing an element having an unpaired electron and capable of coordinating with boron and having a specific structure.

An active matrix type full-color display device is shown. A schematic diagram of display part A of a full-color display device is shown. A schematic diagram of a pixel is shown. It is a schematic diagram of the display apparatus by a passive matrix system. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

The above object of the present invention has been achieved by the following constitution.
(1) An organic electroluminescent element material represented by the following general formula (3) or (4) .

(Wherein R ₁ and R ₂ each independently represents a substituent, L represents a linking group, X represents an element having an unpaired electron and capable of coordinating with a boron atom, Rx represents a hydrogen atom, R ₃ , R ₄ , R ₅ , and R ₆ each independently represent a hydrogen atom or a substituent, n represents 0 or 1, and m represents 1 or 2. Rx may combine with any element of L to form a ring, and R ₁ and R ₂ may combine to form a ring, and Rx combines with R ₆ to form a condensed ring. May be formed.)
(4) An organic electroluminescent element material represented by the following general formula (4).

(Wherein R ₁ and R ₂ each independently represent a substituent, A ₂ represents a residue necessary to form an aromatic carbocyclic ring or a condensed heterocyclic ring, and A ₃ forms a heterocyclic ring. And any element of A ₂ and any element of A ₃ may combine to form a ring, and R ₁ and R ₂ may combine to form a ring. )
(2) The material for an organic electroluminescence element according to (1), which is represented by the general formula (3).
(3) The material for an organic electroluminescence element according to (1), which is represented by the general formula (4).
( 4 ) The organic electroluminescent element material according to any one of (1) to ( 3 ), wherein both R ₁ and R ₂ are an aromatic carbocyclic group or a heterocyclic group.
( 5 ) An organic electroluminescent element using the organic electroluminescent element material according to any one of (1) to ( 4 ).
( 6 ) The organic electroluminescence device as described in ( 5 ) above, which has a light emitting layer containing a phosphorescent light emitting material.
( 7 ) The organic electroluminescent element according to ( 6 ), wherein the light emitting layer contains the organic electroluminescent element material according to any one of (1) to ( 4 ).
( 8 ) Any of the above ( 5 ) to ( 7 ), comprising a hole blocking layer containing the material for an organic electroluminescence device according to any one of (1) to ( 4 ). 2. The organic electroluminescence device according to item 1.
( 9 ) The organic electroluminescence device according to any one of ( 5 ) to ( 8 ), wherein the organic electroluminescence device emits blue light.
( 10 ) The organic electroluminescence device according to any one of ( 5 ) to ( 8 ), which emits white light.
( 11 ) A display device comprising the organic electroluminescence element according to any one of ( 5 ) to ( 10 ).
( 12 ) An illuminating device comprising the organic electroluminescence element according to any one of ( 5 ) to ( 10 ).
( 13 ) A display device comprising the illumination device according to ( 12 ) and a liquid crystal element as display means.

  Hereinafter, the present invention will be described in more detail.

  In the present invention, the boron compound represented by the general formula (1) is used as a host compound or a hole blocking material in an organic EL device material.

In the general formula (1), A ₁ represents a residue necessary for forming an aromatic carbocycle or a heterocycle, and examples of the aromatic carbocycle formed by A ₁ include a benzene ring, a naphthalene ring, Anthracene ring, azulene ring, phenanthrene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, perylene ring, pentacene ring, hexacene ring and the like may be mentioned, and these may have a substituent. Among these, a benzene ring and a naphthalene ring are preferable, and a benzene ring is more preferable.

Examples of the heterocyclic ring formed by A ₁ include carbazole ring, pyridine ring, pyrimidine ring, thiophene ring, furan ring, imidazole ring, pyrazole ring, triazole ring, oxazole ring, thiazole ring, isoxazole, isothiazole ring, Examples thereof include an indole ring, a phenanthroline ring, a quinoline ring, an isoquinoline ring, a quinoline ring, and an oxadiazole ring, and these may have a substituent. Among these, a carbazole ring, a pyridine ring, a pyrimidine ring, a triazole ring, an oxadiazole ring and the like are preferable, and a carbazole ring and a pyridine ring are more preferable.

In the general formula (1), R ₁ and R ₂ each independently represent a substituent, and examples of the substituent represented by R ₁ and R ₂ include an aliphatic group (for example, a methyl group, an ethyl group, a propyl group). Group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, cyclopentyl group, cyclohexyl group, vinyl group, allyl group, ethynyl group, propargyl group, etc.) An aromatic carbocyclic group (for example, phenyl group, naphthyl group, etc.), a heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, Thiazolyl group, benzimidazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, pyrrolidyl group, imidazo Diyl group, morpholyl group, oxazolidyl group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), acyl group (eg, acetyl group, Ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), halogen atom (for example, fluorine) Atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group and the like.

  In the general formula (1), L represents a linking group, and examples of the linking group represented by L include an alkylene group (for example, methylene group, ethylene group, propylene group, etc.), an alkenylene group (for example, vinylene group, etc.). ), Arylene groups (for example, phenylene group, naphthylene group, etc.), heterocyclic groups (for example, furyl group, thienyl group, pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group) , A divalent group derived from a benzoimidazolyl group, a benzoxazolyl group, a quinazolyl group, a phthalazyl group, a pyrrolidyl group, an imidazolidyl group, a morpholyl group, an oxazolidyl group, and the like.

  In the general formula (1), X represents an element having an unpaired electron and capable of coordinating with a boron atom, and examples of an element having an unpaired electron represented by X and capable of coordinating with a boron atom are as follows: A nitrogen atom, an oxygen atom, a sulfur atom, etc. are mentioned.

In the general formula (1), Rx represents a hydrogen atom, an aliphatic group, an aromatic carbocyclic group, or a heterocyclic group. Examples of the aliphatic group, the aromatic carbocyclic group, and the heterocyclic group represented by Rx include , R ₁ may be mentioned.

  In the general formula (1), n represents 0 or 1, and m represents 1 or 2.

  Rx may combine with any element of L to form a ring, and examples of the ring formed by any element of Rx and L include a thiophene ring, a furan ring, an isobenzofuran ring, a chromene ring, Examples include isochromene ring, pyrrole ring, imidazole ring, pyridine ring, pyrimidine ring, pyrazine ring, indole ring, isoindole ring, quinoline ring, isoquinoline ring, carbazole ring, carboline ring and the like.

Rx may combine with any element of A ₁ to form a condensed ring. Examples of the ring formed by any element of Rx and A ₁ include a chromene ring, an indole ring, a quinoline ring, and a quinazoline. Ring, carbazole ring, carboline ring, phenanthroline ring and the like.

In the general formula (2), A ₂ represents a residue necessary for forming an aromatic carbocycle or a heterocycle, and examples of the aromatic carbocycle formed by A ₂ include a benzene ring, a naphthalene ring, Anthracene ring, azulene ring, phenanthrene ring, triphenylene ring, pyrene ring, chrysene ring, naphthacene ring, perylene ring, pentacene ring and hexacene ring may be mentioned, and these may have a substituent. Of these, a benzene ring and a naphthalene ring are preferable, and a benzene ring is more preferable.

Examples of the heterocyclic ring formed by A ₂ include carbazole ring, pyridine ring, pyrimidine ring, thiophene ring, furan ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, isoxazole, isothiazole ring, indole ring, Examples thereof include a phenanthroline ring, a quinoline ring, and an isoquinoline ring, and these may have a substituent. Among these, a carbazole ring, a pyridine ring, and a pyrimidine ring are preferable, and a carbazole ring and a pyridine ring are more preferable.

_R 1 in the general formula _{(2), R 2, L} , X, Rx, m, n are in each _R 1 wherein in the general formula _{(1), R 2, L} , X, Rx, m, n synonymous .

  Rx may combine with any element of L to form a ring. Examples of the ring formed by combining any element of Rx and L include the examples given in general formula (1). Can be mentioned.

Rx may combine with any element of A ₂ to form a condensed ring, and examples of the ring formed by combining R x and any element of A ₂ include, in general formula (1): any element Rx and a ₁ is an example of a ring formed by bond.

_R 1 in the general formula _{(3), R 2, L} , X, Rx, m, n are, _R 1 in the general formula _{(1), R 2, L} , X, Rx, m, is synonymous with n.

In the general formula (3), R ₃ , R ₄ , R ₅ and R ₆ each independently represent a hydrogen atom or a substituent, and examples of the substituent represented by R ₃ , R ₄ , R ₅ and R ₆ Is an aliphatic group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, cyclopentyl group, cyclohexyl group). Group, vinyl group, allyl group, ethynyl group, propargyl group, etc.), aromatic group (for example, phenyl group, naphthyl group, etc.), heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazyl group, pyrimidyl group). , Pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, quinazolyl group, Taradyl group, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), Cycloalkoxy groups (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy groups (eg, phenoxy group, naphthyloxy group, etc.), alkylthio groups (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, , Methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl 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, Chlohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy) Group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexyl group) Carbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, Phthalylcarbonylamino group, etc.), carbamoyl groups (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexyl) Aminocarbonyl 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, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group) Group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group (phenylsulfonyl group, naphthylsulfonyl 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- Lysylamino group, etc.), halogen atoms (eg fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon groups (eg fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group etc.), And cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.).

_R 1, _{R 2} in the general formula (4) has the same meaning as _R 1, _{R 2} in the general formula (1).

_{A 2} in the general formula (4) has the same meaning as _{A 2} in the general formula (2).

In the general formula (4), A ₃ represents a residue necessary for forming a heterocyclic ring. Examples of the heterocyclic ring represented by A ₃ include a pyridine ring, a pyrazine ring, a pyrimidine ring, a quinoline ring, and an isoquinoline. Ring, carboline ring, phenanthroline ring and the like.

  Although the example of the organic EL element material of this invention is shown below, it is not limited to these.

  The synthesis example of the compound of the following this invention is described.

  (Synthesis of Compound 1)

After putting 2.53 g (10.8 mmol) of Intermediate 1 into a 200 ml three-headed flask, the atmosphere was replaced with nitrogen. To this was added 60 ml of diethyl ether and cooled to −78 ° C. Then, 6.81 ml (10.8 mmol) of n-BuLi was added dropwise and stirred for 30 minutes. Thereafter, 0.45 ml (3.59 mmol) of BF ₃ · OEt _{2 was} added, and the mixture was heated to −78 ° C. for 1 hour, then warmed to room temperature and further stirred for 2 hours. This was transferred to a separatory funnel, and 100 ml of ethyl acetate was added, followed by washing with water three times. Thereafter, the organic solvent was removed under reduced pressure, and the residue was separated and purified by silica gel chromatography to obtain 1.0 g of Compound 1.

  Next, the configuration of the organic EL element according to the present invention will be described.

<< Constituent layers of organic EL elements >>
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 << light emitting layer >>
The light emitting layer according to the present invention contains a phosphorescent compound, and is a layer that emits light by recombination of electrons and holes injected from the electrode or the electron transport layer and the hole transport layer. It may be in the light emitting layer or at the interface between the light emitting layer and the adjacent layer.

  The light emitting layer according to the present invention preferably contains the compound represented by the general formula (1) as a host compound (light emitting host).

  In addition, by using a phosphorescent dopant together with the compound represented by the general formula (1) in the light emitting layer according to the present invention, it is possible to obtain a long-life organic EL device with higher luminous efficiency.

  There are two types of light emission of phosphorescent compounds 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, and this energy is phosphorescent. Energy transfer type to obtain light emission from the phosphorescent compound by transferring to the compound, the other is that the phosphorescent compound becomes a carrier trap, carrier recombination occurs on the phosphorescent compound, and from the phosphorescent compound In any case, the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  In the present invention, the phosphorescent maximum wavelength of the phosphorescent compound is not particularly limited. In principle, the phosphorescent compound can be obtained by selecting a central metal, a ligand, a ligand substituent, and the like. However, it is preferable that the phosphorescent compound has a maximum phosphorescence emission wavelength of 380 nm to 480 nm.

  Examples of such phosphorescent emission wavelengths include organic EL elements that emit blue light and organic EL elements that emit white light. These elements should be operated with lower emission voltage and lower power consumption. Can do.

  In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

  The light emitting layer may contain a host compound in addition to the phosphorescent compound.

  In the light emitting layer according to the present invention, the compound represented by the general formula (1) may be used as a host compound, and a plurality of known host compounds may be used in combination. 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. As these known host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing the emission of longer wavelengths, and having a high Tg (glass transition temperature) are 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.

  Moreover, the light emitting layer may contain the host compound which has a fluorescence maximum wavelength further as a host compound. In this case, the energy transfer from the other host compound and the phosphorescent compound to the fluorescent compound allows electroluminescence as an organic EL element to be emitted from the other host compound having a fluorescence maximum wavelength. A host compound having a fluorescence maximum wavelength is preferably a compound having a high fluorescence quantum yield in a solution state. Here, the fluorescence quantum yield is preferably 10% or more, particularly preferably 30% or more. Specific host compounds having a maximum fluorescence wavelength include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, and pyrylium dyes. Perylene dyes, stilbene dyes, polythiophene dyes, and the like. The fluorescence quantum yield can be measured by the method described in 362 (1992 edition, Maruzen) of Spectroscopic II of the Fourth Edition Experimental Chemistry Course 7.

  The color emitted in this specification is the spectral radiance meter CS-1000 (Minolta) in FIG. 4.16 on page 108 of “New Color Science Handbook” (Edited by the Japan Society for Color Science, University of Tokyo Press, 1985). It is determined by the color when the measured result is applied to the CIE chromaticity coordinates.

  The light emitting layer can be formed by forming the above compound 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. Although the film thickness as a light emitting layer does not have a restriction | limiting in particular, Usually, 5 nm-5 micrometers, Preferably it is chosen in the range of 5 nm-200 nm. The light emitting layer may have a single layer structure in which these phosphorescent compounds and host compounds are composed of one or more kinds, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions. Good.

<< Dopant (Fluorescence, Phosphorescence) >>
The light emitting layer according to the present invention preferably contains a dopant, and further preferably contains a phosphorescent dopant. As a result, higher luminous efficiency can be obtained.

  A dopant (also referred to as a light-emitting dopant) that can be used in combination with the host compound of the present invention will be described.

  The dopant is roughly classified into two types: a fluorescent dopant that emits fluorescence and a phosphorescent dopant that emits phosphorescence.

  Representative examples of the former (fluorescent dopant) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, Examples include perylene dyes, stilbene dyes, polythiophene dyes, rare earth complex phosphors, and other known fluorescent compounds.

  The phosphorescent dopant contained in the light emitting layer according to the present invention can be appropriately selected from known materials used for the light emitting layer of the organic EL device. For example, an iridium complex described in JP-A No. 2001-247859, or a formula represented by International Publication No. 00 / 70,655, pages 16 to 18, for example, tris (2-phenylpyridine) A platinum complex such as iridium or the like or an osmium complex, or 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphyrin platinum complex may be used as the dopant. By using such a phosphorescent compound as a dopant, a light-emitting organic EL device with high internal quantum efficiency can be realized.

  The phosphorescent compound used in the present invention is preferably a complex compound containing any one metal belonging to Group 8, Group 10, or Group 10 in the periodic table, more preferably an iridium compound, An osmium compound, a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  These compounds are described, for example, in Inorg. Chem. 40, 1704-1711, and the like.

  In addition, for example, J. et al. Am. Chem. Soc. 123, 4304-4312 (2001), International Publication No. 00/70655 pamphlet, No. 02/15645 pamphlet, JP-A No. 2001-247859, No. 2001-345183, No. 2002-117978, 2002-170684, 2002-203678, 2002-235076, 2002-302671, 2002-324679, 2002-332291, 2002-332292, Examples include iridium complexes represented by general formulas described in 2002-338588 and the like, iridium complexes exemplified as specific examples, iridium complexes represented by formula (IV) described in JP-A-2002-8860, and the like. It is done.

  The phosphorescent compound according to the present invention preferably has a phosphorescence quantum yield in solution of 0.001 or more at 25 ° C., more preferably 0.01 or more, and particularly preferably 0.1 or more. .

  The phosphorescent 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.

<Blocking layer: hole blocking layer, electron blocking layer>
The hole blocking layer is an electron transport layer in a broad sense, and is made of a material that has a function of transporting electrons and has a very small ability to transport holes. By blocking holes while transporting electrons, And the recombination probability of holes can be improved.

  The hole blocking layer has a role of blocking the holes moving from the hole transport layer from reaching the cathode and a compound that can efficiently transport the electrons injected from the cathode toward the light emitting layer. It is formed. The physical properties required of the material constituting the hole blocking layer are higher than the ionization potential of the light emitting layer in order to have high electron mobility and low hole mobility and to efficiently confine holes in the light emitting layer. It is preferable to have a value of ionization potential or a band gap larger than that of the light emitting layer.

  It is preferable to use the compound represented by the general formula (1) of the present invention as a hole blocking material. In addition, as a known hole blocking material, it is effective to obtain at least one of a styryl compound, a triazole derivative, a phenanthroline derivative, an oxadiazole derivative, and a boron derivative for obtaining the effects of the present invention.

  Examples of other hole blocking materials include exemplified compounds described in JP-A Nos. 2003-31367, 2003-31368, and No. 2721441.

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

  The hole blocking layer and the electron blocking layer can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. .

  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, Conventionally known materials such as stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers, may be used.

  As the hole transport material, those described above can be used, 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 two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in No. 88 are linked in a starburst type ) 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.

  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 nm-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials.

《Electron transport layer》
The electron transport layer according to the present invention is only required to have a function of transmitting electrons injected from the cathode to the light emitting layer, and as the material thereof, any one of conventionally known compounds can be selected and used. Can do.

  Examples of materials used for this electron transport layer (hereinafter referred to as electron transport materials) include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, carbodiimides, Examples include fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, and oxadiazole derivatives. Furthermore, in the 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.

  Or metal complexes of 8-quinolinol derivatives, such as tris (8-quinolinol) aluminum (Alq3), 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), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga, or Pb can also be used as an electron transport material.

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

  The electron transport layer can be formed by forming the above compound by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method.

(Film thickness of electron transport layer)
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 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

"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 an electrode substance include conductive transparent materials such as metals such as Au, 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, a thin film may be formed by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (100 μm or more) Degree), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. When light emission is extracted from the anode, it is desirable that the transmittance is 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 nm to 1000 nm, preferably 10 nm 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₎ mixture, indium, a lithium / aluminum mixture, and rare earth metals. Among these, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this, such as a magnesium / silver mixture, magnesium, from the viewpoint of electron injectability and durability against oxidation, etc. / Aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

  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 by the film thickness of 1 nm-20 nm to a cathode, the 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.

<< Buffer layer >>: Anode buffer layer, cathode buffer layer An injection layer is provided as necessary, and includes a cathode buffer layer (electron injection layer) and an anode buffer layer (hole injection layer). You may exist between a positive hole transport layer and between a cathode and a light emitting layer or an electron carrying layer.

  The buffer layer is a layer that is provided between the electrode and the organic layer in order to lower the driving voltage and improve the light emission luminance. “The organic EL element and the forefront of its industrialization (November 30, 1998, issued by NTT Corporation) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes an anode buffer layer and a cathode buffer layer.

  The details of the anode buffer layer (hole injection layer) are described in JP-A Nos. 9-45479, 9-260062, and 8-288069. Specific examples thereof include copper phthalocyanine. Examples thereof include a phthalocyanine buffer layer, an oxide buffer layer typified 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. A metal buffer layer typified by lithium fluoride, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, an 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.

<< Substrate (also referred to as substrate, substrate, support, etc.) >>
The organic EL device of the present invention is preferably formed on a substrate.

  The substrate of the organic EL device of the present invention is not particularly limited to the type of glass, plastic, etc., and is not particularly limited as long as it is transparent. Examples of substrates that are preferably used include glass, quartz, A light transmissive resin film can be mentioned. A particularly preferable substrate is a resin film that can give flexibility to the organic EL element.

  Examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose triacetate. Examples thereof include films having (TAC), cellulose acetate propionate (CAP) and the like. In addition, an inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film.

  The external extraction quantum efficiency at room temperature of light emission of the organic electroluminescence 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 may be used in combination. 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.

<< 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 / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode. explain.

  First, a thin film made of a desired electrode material, for example, an anode material ITO, 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 nm to 200 nm. Make it. Next, an organic compound thin film of an anode buffer layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and a cathode buffer layer, which are organic EL element materials, is formed thereon.

As a method for thinning the organic compound thin film, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, printing method) as described above, but it is easy to obtain a uniform film and a pinhole. From the point of being difficult to form, a vacuum deposition method, a spin coating method, an ink jet method, and a printing method are particularly preferable. Further, different film forming methods may be applied for each layer. When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 ° C. to 450 ° C., a vacuum degree of 10 ⁻⁶ Pa to 10 ⁻² Pa, and a vapor deposition rate of 0. It is desirable to select appropriately within the range of 0.01 nm / second to 50 nm / second, substrate temperature −50 ° C. to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 nm to 200 nm.

  After these layers are formed, a cathode material, for example, a thin film made of Al is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm. By providing, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  The multicolor display device of the present invention is provided with a shadow mask only when the light emitting layer is formed, and the other layers are common, so that patterning of the shadow mask or the like is unnecessary, and the evaporation method, the casting method, the spin coating method, the ink jet method on one side. A film can be formed by a method or a printing method.

  When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

  In addition, it is also possible to reverse the production order to produce a cathode, a cathode buffer layer, an electron transport layer, a hole transport layer, a light emitting layer, a hole transport layer, an anode buffer layer, and an 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 positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

  The display device of the present invention can be used as a display device, a display, and various light emission sources. In a display device or a display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  The lighting device of the present invention includes 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 sensors Although a light source etc. are mentioned, it is not limited to this.

  Further, the organic EL element according to the present invention may be used as an organic EL element having a resonator structure.

  Examples of the purpose of use of the organic EL element having such a resonator structure include a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processing machine, and a light source of an optical sensor. It is not limited. Moreover, you may use for the said use by making a laser oscillation.

<Display device>
The organic EL element of the present invention may be used as one kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display). When used as a display device for reproducing moving images, the driving method may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using three or more organic EL elements of the present invention having different emission colors. Alternatively, it is possible to make a single color emission color, for example, white emission, into BGR using a color filter to achieve full color. Further, it is possible to convert the emission color of the organic EL to another color by using a color conversion filter, and in this case, λmax of the organic EL emission is preferably 480 nm or less.

  An example of a display device having the organic EL element of the present invention as a configuration will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating an example of a display device including organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

  The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from the outside. The pixels for each scanning line are converted into image data signals by the scanning signal. In response to this, light is sequentially emitted and image scanning is performed to display image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below. FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at orthogonal positions (details are shown in FIG. Not shown).

  When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data. Full color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region that emit light on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 shows a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.

  When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or on / off of a predetermined light emission amount by a binary image data signal. But you can.

  The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic view of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal. In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, the embodiment of this invention is not limited to these.

Example 1
<Preparation of organic EL elements 1-1 to 16>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass) made of ITO (indium tin oxide) with a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is put in a molybdenum resistance heating boat, and 200 mg of compound 1 as a host compound is put in another molybdenum resistance heating boat. 200 mg of Bathocuproin (BCP) is put into a resistance heating boat made of molybdenum, 100 mg of Ir-12 is put into another resistance heating boat made of molybdenum, and 200 mg of Alq ₃ is put into another resistance heating boat made of molybdenum, and is attached to a vacuum deposition apparatus. It was.

Next, after the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / sec. The first hole transport layer was provided. Further, the heating boat containing the compound 1 and Ir-12 was energized and heated, and co-deposited on the hole transport layer at a deposition rate of 0.2 nm / sec and 0.012 nm / sec, respectively, to a film thickness of 30 nm. The light emitting layer was provided. In addition, the substrate temperature at the time of vapor deposition was room temperature. In addition, an electron transport layer that also serves as a hole blocking function with a film thickness of 10 nm is provided by energizing and heating the heating boat containing BCP and depositing on the light emitting layer at a deposition rate of 0.1 nm / sec. It was. On top of that, the heating boat containing Alq ₃ was further energized and heated, and deposited on the electron transport layer at a deposition rate of 0.1 nm / sec to further provide an electron injection layer having a thickness of 40 nm. . In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the organic EL element 1-1 was produced.

  In the production of the organic EL device 1-1, 1-2 was performed in the same manner as the organic EL device 1-1 except that the compound 1 shown in Table 1 was used as the host compound by replacing the exemplified compound 1 used as the host compound in the light emitting layer. ˜1-16 were produced. The structure of each compound used above is shown below.

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

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

  The measurement results of the external extraction quantum efficiency in Table 1 are expressed as relative values when the measured value of the organic EL element 1-16 is 100.

  From Table 1, it was found that the organic EL device of the present invention was very excellent in external extraction quantum efficiency.

Example 2
<Preparation of organic EL elements 2-1 to 2-16>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass) made of ITO (indium tin oxide) with a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes. This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of α-NPD is put in a molybdenum resistance heating boat, and 200 mg of CBP is put in another molybdenum resistance heating boat, and another molybdenum resistance is added. 200 mg of Compound 1 as a hole blocking material was put into a heating boat, 100 mg of Ir-1 was put into another molybdenum resistance heating boat, and 200 mg of Alq ₃ was put into another resistance heating boat made of molybdenum, and attached to a vacuum deposition apparatus. .

Next, after the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / sec. The first hole transport layer was provided. Further, the heating boat containing CBP (Comparative Compound 1 in Example 1) and Ir-1 was energized and heated, and the deposition rate was 0.2 nm / sec and 0.012 nm / sec on the hole transport layer, respectively. A light emitting layer having a thickness of 30 nm was provided by co-evaporation. In addition, the substrate temperature at the time of vapor deposition was room temperature. Further, the electron transporting layer also serves as a hole blocking layer having a film thickness of 10 nm by being heated by energizing the heating boat containing the compound 1 and being deposited on the light emitting layer at a deposition rate of 0.1 nm / sec. Was provided. On top of that, the heating boat containing Alq ₃ was further energized and heated, and deposited on the electron transport layer at a deposition rate of 0.1 nm / sec to further provide an electron injection layer having a thickness of 40 nm. . In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited to form a cathode, and an organic EL element 2-1 was produced.

  In the production of the organic EL element 2-1, 2-1 to 2-16 were produced in the same manner as the organic EL element 2-1, except that the compound 1 used as the hole blocking material was replaced with the compound shown in Table 2. did. Comparative compound 3 is BCP used as the hole blocking compound in Example 1.

<Evaluation of organic EL elements 2-1 to 2-16>
The external extraction quantum efficiency of the organic EL elements 2-1 to 2-16 was evaluated in the same manner as in Example 1. Furthermore, the lifetime was evaluated according to the measurement method shown below.

(lifespan)
When driven 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. A spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used for the measurement.

  The measurement results of external extraction quantum efficiency and lifetime in Table 2 are expressed as relative values when the organic EL element 2-15 is set to 100.

  From Table 2, it was found that the organic EL device of the present invention achieved a long lifetime.

Example 3
The organic EL device 1-1 of the present invention produced in Example 1, the organic EL device 2-7 of the present invention produced in Example 2, and the phosphorescent compound of the organic EL device 2-7 of the present invention are shown below. A red light-emitting organic EL element produced in the same manner except that Btp ₂ Ir (acac) was replaced was juxtaposed on the same substrate to produce an active matrix type full-color display device shown in FIG. FIG. 2 shows only a schematic diagram of the display portion A of the produced full-color display device. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) on the same substrate. Each of the scanning lines 5 and the plurality of data lines 6 in the wiring portion is made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (details). Is not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, full-color display is possible by appropriately juxtaposing the red, green, and blue pixels.

  By driving the full-color display device, a clear full-color moving image display with high external extraction quantum efficiency and good durability was obtained.

Example 4
In the organic EL device 1-1 produced in Example 1, the heating boat containing Compound 1, the boat containing Ir-12, and the boat containing Btp ₂ Ir (acac) were energized independently, and the light emitting host was used. Except for adjusting the deposition rate of certain compound 1 and the luminescent dopants Ir-12 and Btp ₂ Ir (acac) to 100: 5: 0.6, and providing the light emitting layer so that the film thickness is 30 nm. Produced the organic EL element 1-1W by the same method as the organic EL element 1-1. The non-light-emitting surface of the obtained organic EL element 1-1W was covered with a glass case, and the lighting device shown in FIGS. 5 and 6 was obtained. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life. FIG. 5 is a schematic view of the lighting device, and FIG. 6 is a cross-sectional view of the lighting device. The organic EL element 100 is covered with a glass cover 102, the glass substrate 101 with a transparent electrode and the glass cover 102 are sealed with a sealant 107, and a power line (anode) 103 and a power line (cathode) 104 are connected. Has been. 105 is a cathode and 106 is an organic EL layer. The glass cover 102 is filled with nitrogen gas 108 and a water replenisher 109 is provided.

  According to the present invention, an organic EL element material having high luminous efficiency, an organic EL element using the organic EL element material, an illumination device, and a display device can be provided. Furthermore, it was possible to provide an organic EL element material having a long life, an organic EL element using the organic EL element material, an illumination device, and a display device.

Claims (13)

An organic electroluminescent element material represented by the following general formula (3) or (4):

(In the formula, R ₁ and R ₂ each independently represent a substituent, L represents a linking group, X represents a nitrogen atom, an oxygen atom or a sulfur atom which has an unpaired electron and can be coordinated to a boron atom. , Rx represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, R ₃ , R ₄ , R ₅ , or R ₆ each independently represents a hydrogen atom or a substituent, and n represents 0 or 1 , M represents 1 or 2, and Rx may combine with any element of L to form a ring, or R ₁ and R ₂ may combine to form a ring. ₆ may form a condensed ring.

(Wherein R ₁ and R ₂ each independently represent a substituent, A ₂ represents a residue necessary to form an aromatic carbocyclic ring or a condensed heterocyclic ring, and A ₃ forms a heterocyclic ring. And any element of A ₂ and any element of A ₃ may combine to form a ring, and R ₁ and R ₂ may combine to form a ring. ) It represents with the said General formula (3), The organic electroluminescent element material of Claim 1 characterized by the above-mentioned . It represents with the said General formula (4), The organic electroluminescent element material of Claim 1 characterized by the above-mentioned . 4. The material for an organic electroluminescent element according to claim ₁ , wherein both R ₁ and R ₂ are an aromatic carbocyclic group or a heterocyclic group . The organic electroluminescent element using the organic electroluminescent element material of any one of Claims 1-4. 6. The organic electroluminescence device according to claim 5, further comprising a light emitting layer containing a phosphorescent light emitting material. The organic electroluminescent element according to claim 6, wherein the light emitting layer contains the organic electroluminescent element material according to claim 1. It has a hole-blocking layer containing the organic electroluminescent element material of any one of Claims 1-4, The organic electroluminescent element of any one of Claims 5-7 characterized by the above-mentioned. . The organic electroluminescent element according to claim 5, which emits blue light. The organic electroluminescence element according to claim 5, which emits white light. A display device comprising the organic electroluminescence element according to claim 5. An illuminating device comprising the organic electroluminescence element according to any one of claims 5 to 10. 13. A display device comprising: the lighting device according to claim 12; and a liquid crystal element as display means.

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