JP5636630B2 - ORGANIC ELECTROLUMINESCENT ELEMENT MATERIAL, ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE AND LIGHTING DEVICE - Google Patents

Description

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

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements). Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic EL device has a structure in which a light-emitting layer containing a light-emitting compound is sandwiched between a cathode and an anode, and excitons (excitons) are generated by injecting electrons and holes into the light-emitting layer and recombining them. The device emits light by utilizing 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. Therefore, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoints of space saving and portability.

  For the development of organic EL elements for practical application, M.M. A. Baldo et al. Since 1993, Nature, 395, 151-154 (1998), Princeton University reported on organic EL devices using phosphorescence emission from excited triplets. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) and US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

  Furthermore, the recently discovered organic EL device using phosphorescence emission can in principle achieve light emission efficiency about 4 times that of the previous device using fluorescence emission. Research and development of light-emitting element layer configurations and electrodes are performed all over the world.

  For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), a number of compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes.

  On the other hand, the organic EL element manufacturing methods are roughly classified into two methods: film formation by vapor deposition (dry process) and solution coating / film formation (wet process). An excellent wet process in terms of high productivity has attracted attention.

  In the organic EL elements having a multi-layer structure which is currently mainstream, development of a laminating method by coating and a material capable of being coated and laminated is required.

  Since the wet process can be formed at a low temperature as compared with the vacuum process, damage to the underlying organic layer can be reduced, and there are great expectations in terms of improving the light emission efficiency and the device life. Examples of electrode film formation by a wet process include using PEDOT / PSS in place of the ITO anode, applying low-melting metal paste (see, for example, Patent Document 1), and applying conductive paste material. A cathode forming method using a film (for example, see Patent Document 2) has been reported. However, from the viewpoint of practical use, it is still insufficient in terms of performance deterioration during high-temperature storage, and further improvement techniques are indispensable.

JP 2005-285732 A JP 2005-514729 A

  An object of the present invention is to provide an organic electroluminescence element having a high external extraction quantum efficiency, a long emission lifetime, a low driving voltage and excellent high-temperature storage stability, an organic electroluminescence element material therefor, and a display device using the organic EL element And providing a lighting device.

  The above object of the present invention is achieved by the following configurations.

  1. An organic electroluminescent element material comprising a polymer compound represented by the following general formula (1).

(Formula (1) _X 1 ~X ₇ in represents N atom or CR group, R represents a hydrogen atom or a substituent. _However, a single N atoms of X 1 to X _4, and / _or, one of X 5 to X ₇ is N atom, the other is CR group. Further, _{X 1} and _X 2, _{X 2} and _X 3, _{X 3} and _X 4, _{X 6} and _{X 7} Are simultaneously CR groups, R may be bonded to each other to form a 5-membered or 6-membered aromatic ring, where n represents the average degree of polymerization, and 3 ≦ n ≦ 1000.
2. Furthermore, 0.01-50 mass% of alkali metal compounds or alkaline-earth metal compounds are contained with respect to the high molecular compound represented by the said General formula (1), The organic electroluminescent element of said 1 characterized by the above-mentioned. material.

  3. An organic electroluminescent element having at least an organic layer between opposing electrodes, wherein the organic layer has the organic electroluminescent element material described in 1 or 2 above.

  4). 4. The organic electroluminescence device as described in 3 above, wherein the organic layer is an electron transport layer.

  5. The organic layer according to 3 or 4 above, wherein the organic layer is composed of a plurality of layers, one of which is a light emitting layer, and a compound represented by the following general formula (2) is included as a host compound. Electroluminescence element.

Formula ₍₂₎ L n -Q _m
(Wherein L is a condensed aromatic heterocyclic ring which may be substituted, Q is an optionally substituted aromatic hydrocarbon ring or aromatic heterocyclic ring, and n and m are each an integer of 1 to 3) L may be different from each other when n is 2 or more, and Q may be different from each other when m is 2 or more.)
6). 6. The organic electroluminescence device as described in 5 above, wherein L of the compound represented by the general formula (2) is represented by the following general formula (3).

(In the formula, A represents an O atom, an S atom, and an NR ₉ group. R _{1 to} R ₉ represent a hydrogen atom or a substituent.)
7). 7. The organic electroluminescence device according to any one of 3 to 6, which emits white light.

  8). A display device comprising the organic electroluminescence element according to any one of 3 to 7 above.

  9. An illuminating device comprising the organic electroluminescence element according to any one of 3 to 7 above.

  According to the present invention, an organic electroluminescence element having a high external extraction quantum efficiency, a long emission lifetime, a low driving voltage, and excellent high-temperature storage stability, an organic electroluminescence element material therefor, a display device using the organic EL element, and A lighting device could be provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full color display device. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

  Hereinafter, the present invention will be described in detail.

  The organic electroluminescence device material of the present invention contains a polymer compound represented by the general formula (1), and an alkali metal compound or an alkaline earth metal compound is represented by the general formula (1). It is characterized by containing 0.01 to 50% by mass with respect to the polymer compound. Moreover, the organic electroluminescent element of this invention contains this organic electroluminescent element material.

In the general formula (1), X _{1 to} X ₇ each represent an N atom or a CR group, and R represents a hydrogen atom or a substituent. However, at least one of X _{1 to} X ₇ is an N atom. When X ₁ and X ₂ , X ₂ and X ₃ , X ₃ and X ₄ , X ₆ and X ₇ are CR groups at the same time, Rs are bonded to each other to form a 5-membered or 6-membered aromatic ring. May be.

  Examples of the substituent represented by R include a cycloalkyl group, an alkynyl group, and an aromatic hydrocarbon ring group (also referred to as an aromatic carbocyclic group and an aryl group, such as a phenyl group, a p-chlorophenyl group, a mesityl group, Tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl) Group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), Oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazo Group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (the carboline ring of the carbolinyl group is One of the constituent carbon atoms is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group) Group), alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, alkoxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, Vamoyl group, ureido group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group or heteroarylsulfonyl group, amino group, halogen atom, fluorinated hydrocarbon group, cyano group, nitro group, hydroxy group, mercapto group, silyl group, etc. Can be mentioned.

  The average degree of polymerization n represents 3 ≦ n ≦ 1000, preferably 3 ≦ n ≦ 500, more preferably 5 ≦ n ≦ 100.

  Hereinafter, although the high molecular compound represented by General formula (1) is shown, it is not limited to these.

  Hereinafter, synthesis examples of the polymer compound represented by the general formula (1) are shown.

Synthesis example (PCz-1)
6-bromo-4-azacarbazole (494 mg, 2 mmol), palladium acetate (45 mg, 0.2 mmol), tri-t-butylphosphine (80 mg, 0.4 mmol), sodium-t-butoxide (231 mg, 2.4 mmol) Was added to 50 ml of xylene and heated under reflux for 3 hours under a nitrogen stream. After completion of the reaction, insoluble matters were filtered off, and 10 ml of hexane was added to the resulting solution for reprecipitation. Further, the obtained compound was dissolved in 20 ml of xylene while heating, and 10 ml of hexane was added for reprecipitation. By repeating the same operation twice, 80 mg of the desired PCz-1 could be obtained.

  About molecular weight, molecular weight distribution, etc., it determined by HPLC (high performance liquid chromatography) using the following GPC (gel permeation chromatography) column. As a result, the number average molecular weight was 3,500.

Measuring device: HLC-8220 GPC (high-speed GPC device)
Column used: TSKgel SuperHM-M (exclusion limit: 4 × 106)
Solvent amount: Tetrahydrofuran (THF)
Measurement temperature: 40 ° C
Column flow rate: 0.6 ml / min Calibration curve: A calibration curve was prepared using standard polystyrene.

  Other polymer compounds represented by the general formula (1) can also be synthesized in the same manner as described above. Further, other known synthesis / polymerization reactions may be used in combination. Further, after the polymerization reaction, the polymer terminal may be treated by N-arylation reaction or aryl halide reduction reaction.

  In the general formula (2), L is a condensed aromatic heterocyclic ring which may be substituted, Q is an optionally substituted aromatic hydrocarbon ring or aromatic heterocyclic ring, and n and m are each 1 to It is an integer of 3. L may be different from each other when n is 2 or more, and Q may be different from each other when m is 2 or more.

  The compound represented by the general formula (2) is a compound represented by any one of the following general formulas (4) to (100).

  In the compound represented by the general formula (2) or the compound represented by any one of the general formulas (4) to (100), as the condensed aromatic heterocyclic ring which may be substituted represented by L, Specifically, acridine ring, benzoquinoline ring, carbazole ring, phenazine ring, phenanthridine ring, phenanthroline ring, carboline ring, cyclazine ring, kindrin ring, tepenidine ring, quinindrine ring, triphenodithiazine ring, triphenodioxazine Ring, phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (representing any one of carbon atoms constituting carboline ring replaced by nitrogen atom), phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, Naphthofuran ring, naphthothiophene ring, benzodifuran ring, benzodi Examples include offene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, thiophanthrene ring (naphthothiophene ring), etc. .

  Of these, carbazole ring, carboline ring, dibenzofuran ring, dibenzothiophene ring and the like are preferable.

  Moreover, these rings may have the substituent mentioned later.

  In the compound represented by the general formula (2) or the compound represented by any one of the general formulas (4) to (100), an optionally substituted aromatic hydrocarbon ring represented by Q is benzene. Ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, Examples include a coronene ring, a fluorene ring, a fluoranthrene ring, a naphthacene ring, a pentacene ring, a perylene ring, a pentaphen ring, a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring.

  Furthermore, these rings may have a substituent described later.

  In the compound represented by the general formula (2) or the compound represented by any one of the general formulas (4) to (100), an optionally substituted aromatic heterocyclic ring represented by Q includes a furan ring. Thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole Ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, constituting diazacarbazole ring (carboline ring) One of the carbon atoms It shows a ring that is conversion) and the like.

  Furthermore, these rings may have a substituent described later.

  In this invention, it is preferable that L of the compound represented by General formula (2) based on this invention is represented by the said General formula (3).

When R _{1 to} R ₉ represent a substituent, including the —NR ₉ group represented by A in the general formula (3), examples of the substituent include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group). Group, t-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl) Group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon Group (also called aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tri Group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, etc.), aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl) Group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (of any carbon atom constituting the carboline ring of the carbolinyl group) One of which is replaced by a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), an alkoxy group (eg, methoxy group, ethoxy group, propyloxy) Group, pentyloxy group, hex Ruoxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group) 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 groups (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl groups For example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylamino) Sulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, Octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group Etc.), acyloxy groups (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide groups (for example, methylcarbonylamino group, ethyl) Carbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group ), Carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentyla) Nocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methyl Ureido 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, naphthylsulfur Sulfonyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or hetero Arylsulfonyl group (for example, 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-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trif. Fluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.) ), A phosphono group, and the like.

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  Moreover, it is preferable that the compound represented by General formula (2) based on this invention has an at least 1 pyridine ring.

  Hereinafter, although the specific example of the compound used preferably is shown as a compound represented by General formula (2) based on this invention, this invention is not limited to these.

  The compound represented by the general formula (2) according to the present invention is disclosed in JP 2007-288035 A, Chem. Mater. It can be synthesized by referring to known methods described in 2008, 20, 5951, Experimental Chemistry Course 5th Edition (Edited by Chemical Society of Japan).

  The organic electroluminescence element material of the present invention preferably contains 0.01 to 50% by mass of an alkali metal compound or an alkaline earth metal compound with respect to the polymer compound represented by the general formula (1).

  The alkali metal according to the present invention refers to an element excluding hydrogen among elements belonging to Group 1 (hydrogen, lithium, sodium, potassium, rubidium, cesium, francium) in the periodic table. The alkaline earth metal refers to a typical element (beryllium, magnesium, calcium, strontium, barium, radium) belonging to Group 2 of the periodic table.

  The alkali metal compound and alkaline earth metal compound according to the present invention refer to a salt, complex, oxide or the like containing the alkali metal or alkaline earth metal element.

  In the present invention, an alkali metal compound or an alkaline earth metal compound is preferably contained at the interface between the electron transport layer and the adjacent cathode. As an aspect thereof, it is preferable that the cathode contains an alkali metal compound or an alkaline earth metal compound, or the electron transport layer contains an alkali metal compound or an alkaline earth metal compound.

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL element, a method for producing an element comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, to produce an anode.

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, or an electron transport layer, which is an element material, is formed thereon.

  Here, as the wet method, there are a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spray coating method, a curtain coating method, etc., but a precise thin film can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer.

  After the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Further, the order can be reversed, and the cathode, the electron transport layer, the hole blocking layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode can be formed 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 V 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 organic EL device of the present invention 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.

<< Layer structure of organic EL element >>
Next, although the preferable specific example of the layer structure of the organic EL element of this invention is shown below, this invention is not limited to these.

(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode << light emitting layer >>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The film thickness of the light emitting layer is not particularly limited, but it is 2 from the viewpoint of the uniformity of the film to be formed, the application of unnecessary high voltage during light emission, and the improvement of the stability of the emission color with respect to the drive current. It is preferable to adjust to the range of -200 nm, More preferably, it adjusts to the range of 5-100 nm.

  The light emitting layer of the organic EL device of the present invention preferably contains at least one of a host compound and a light emitting dopant as a guest material, and more preferably contains a host compound and three or more light emitting dopants. Hereinafter, a host compound (also referred to as a light emitting host or the like) and a light emitting dopant contained in the light emitting layer will be described.

(Host compound)
The host compound according to the present invention will be described.

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

  The compound represented by the general formula (2) according to the present invention is also preferably used as the host compound according to the present invention.

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

  The light emitting host used in the present invention may be a conventionally known low molecular weight compound or a high molecular weight compound having a repeating unit, and a low molecular weight compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). Light emitting host).

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

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

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

(Luminescent dopant)
The light emitting dopant according to the present invention will be described.

  Since the organic EL device of the present invention is phosphorescent, it contains at least a phosphorescent dopant as the luminescent dopant according to the present invention.

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

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

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

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound. Energy transfer type to obtain light emission from the phosphorescent dopant by moving to the phosphorescent dopant, the other is the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, Although it is a carrier trap type in which light emission from a phosphorescent dopant can be obtained, in any case, the excited state energy of the phosphorescent dopant is lower than the excited state energy of the host compound. is there.

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

  The phosphorescent dopant according to the present invention is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex system). Compound) and rare earth complexes, and most preferred is an iridium compound.

  Hereinafter, although the specific example of the light emission dopant which may be used for formation of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

<< Charge injection layer: electron injection layer, hole injection layer >>
The charge injection layer according to the present invention is provided as necessary, and includes an electron injection layer and a hole injection layer, and as described above, between the anode and the light emitting layer or the hole transport layer, and the cathode and the light emitting layer or the electron transport layer. It may be present between.

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

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

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

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

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

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

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

  The hole blocking layer preferably contains the azacarbazole derivative mentioned as the host compound.

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode.

  Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

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

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

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

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the recombination probability of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transporting layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

<< Charge transport layer: electron transport layer, hole transport layer >>
Examples of the charge transport layer according to the present invention include an electron transport layer and a hole transport layer. Hereinafter, the electron transport layer and the hole transport layer according to the present invention will be described in detail.

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

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

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

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

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

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

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. About the film thickness of a positive hole transport layer, it is preferable that it is the range of 5 nm-5 micrometers, More preferably, it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

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

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

  Hereinafter, although the specific example of the compound preferably used for formation of the positive hole transport layer of the organic EL element of this invention is given, this invention is not limited to these.

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

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

  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.

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

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material.

  In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method.

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

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

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

  Hereinafter, although the specific example of the compound (electron transport material) preferably used together for formation of the electron carrying layer of the organic EL element of this invention is given, this invention is not limited to these.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.

  For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less.

  Further, although the film thickness depends on the material, it is preferably in the range of 10 to 1000 nm, more preferably in the range of 10 to 200 nm.

"cathode"
As the cathode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound and a mixture thereof as an electrode material is used.

Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

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

  The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is preferably in the range of 10 nm to 5 μm, more preferably in the range of 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 light emission luminance is improved, which is convenient.

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

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

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

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. Water vapor permeability measured by a method in accordance with JIS K 7129-1992 (25 ± 0.5 ° C., It is preferably a barrier film having a relative humidity (90 ± 2)% RH) of 0.01 g / (m ² · 24 h) or less, and further, the oxygen permeability measured by a method according to JIS K 7126-1987. However, it is preferable that it is a high barrier film whose 10 < ^-3 > ml / (m < ² > 24h * MPa) or less and water-vapor permeability are 10 < ^-5 > g / (m < ² > 24h) or less.

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

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

  Examples of the opaque substrate include a metal plate such as aluminum and stainless steel, a film, an opaque resin substrate, a ceramic substrate, and the like.

  The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

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

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

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

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

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

Furthermore, the polymer film, measured oxygen permeability by the method based on JIS K 7126-1987 is ^{1 × 10 -3 ml / m 2} / 24h or less, as measured by the method based on JIS K 7129-1992 water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably that of ^{1 × 10 -3 g / (m} 2 / 24h) or less.

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

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

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

  In addition, it is also possible to suitably form an inorganic or organic layer as a sealing film by covering the electrode and the organic layer on the outer side of the electrode facing the substrate with the organic layer interposed therebetween, and in contact with the substrate. In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.

  Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

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

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

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

《Light extraction》
An organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1), and only about 15% to 20% of light generated in the light emitting layer can be extracted. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method for improving efficiency by giving light condensing property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method for forming a reflective surface on the side surface of an organic EL element (Japanese Patent Laid-Open No. 1-220394), a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the substrate and the light emitter (Japanese Patent Laid-Open No. 62-172691), and lowering the refractive index than the substrate between the substrate and the light emitter. A method of introducing a flat layer having a structure (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer, and a light emitting layer (including between the substrate and the outside) No. 283751) .

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

  In the present invention, by combining these means, it is possible to obtain an organic EL device having further high luminance or durability.

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

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

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

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency.

  This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction, such as first-order diffraction or second-order diffraction, and light generated from the light-emitting layer. Of these, light that cannot be emitted due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode) It is intended to be taken out.

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

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

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

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

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

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

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

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, Sumitomo 3M brightness enhancement film (BEF) can be used.

  As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

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

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

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

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

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

<Display device>
The display device of the present invention will be described. The display device of the present invention comprises the organic EL element of the present invention.

  Although the display device of the present invention may be single color or multicolor, the multicolor display device will be described here. In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.

  In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.

  The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

  In the case of applying a DC voltage to the obtained multicolor display device, light emission can be observed by applying a voltage of about 2V to 40V with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

  The multicolor display device can be used as a display device, a display, and various light emission sources. In a display device or 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.

  Light emitting sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. However, the present invention is not limited to these.

  Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a display device composed of 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 a plurality of pixels based on image information from the outside, and the pixels for each scanning line respond to the image data signal by the scanning signal. The image information is sequentially emitted to scan the image and display the 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.

  In the figure, the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning line 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 the orthogonal positions (details are illustrated). Not)

  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 on the same substrate.

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

  FIG. 3 is 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 light emission of the organic EL element 10 is performed by providing the switching transistor 11 and the drive transistor 12 which are active elements with respect to 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 by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be maintained 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 diagram 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.

《Lighting device》
The lighting device of the present invention will be described. The illuminating device of this invention has the said organic EL element.

  The organic EL element of the present invention may be used as an organic EL element having a resonator structure. The purpose of use of the organic EL element having such a resonator structure is as follows. The light source of a machine, the light source of an optical communication processing machine, the light source of a photosensor, etc. are mentioned, However, It is not limited to these. Moreover, you may use for the said use by making a laser oscillation.

  The organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device that projects an image, or a type that directly recognizes a still image or a moving image. It may be used as a display device (display).

  The driving method when used as a display device for moving image reproduction 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 two or more organic EL elements of the present invention having different emission colors.

  The organic EL material of the present invention can be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of light emission colors is a combination of a plurality of phosphorescent or fluorescent light emitting materials, a light emitting material that emits fluorescent light or phosphorescent light, and light from the light emitting material as excitation light. In combination with a dye material that emits light as a light emitting material, in the white organic EL device of the present invention, a plurality of light emitting dopants may be mixed and mixed.

  It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask etc. is unnecessary, In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is also improved.

  According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

  There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

<< One Embodiment of Lighting Device of the Present Invention >>
One aspect of the lighting device of the present invention that includes the organic EL element of the present invention will be described.

  The non-light emitting surface of the organic EL element of the present invention is covered with a glass case, a 300 μm thick glass substrate is used as a sealing substrate, and an epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is used as a sealing material. ), And this is placed on the cathode and adhered to the transparent support substrate, irradiated with UV light from the glass substrate side, cured and sealed, and an illumination device as shown in FIGS. Can be formed.

  FIG. 5 shows a schematic diagram of the lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is performed without bringing the organic EL element 101 into contact with the atmosphere. (This was performed in a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more)).

  6 shows a cross-sectional view of the lighting device. In FIG. 6, reference numeral 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

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

Example 1
<< Production of Organic EL Element 1-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning was performed on a substrate (NH-Techno Glass NA-45) in which ITO (indium tin oxide) was formed to a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

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

  On this hole transport layer, a solution prepared by dissolving 40 mg of HS-117 and 2 mg of PD-1 in 3 ml of dehydrated mesitylene was formed by spin coating at 1000 rpm for 30 seconds. Heat-dried at 150 degreeC for 1 hour, and provided the light emitting layer with a film thickness of 40 nm.

  On this light emitting layer, a solution prepared by dissolving 15 mg of PCz-1 in 3 ml of dehydrated 1,1,1,3,3,3-hexafluoroisopropanol was formed by spin coating at 1000 rpm for 30 seconds. . Heat-dried at 120 ° C. for 1 hour to provide an electron transport layer having a thickness of 20 nm.

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

<< Production of Organic EL Elements 1-2 to 1-17 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-17 were produced in exactly the same manner except that PCz-1 used for the electron transport layer was changed to the compounds shown in Table 1 below. .

<< Evaluation of Organic EL Elements 1-1 to 1-17 >>
When evaluating the obtained organic EL elements 1-1 to 1-17, the non-light emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 5 and 6 was formed and evaluated.

[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. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.

[Luminescence life]
When driving at a constant current of ^2.5 mA / cm ^{2 in} a dry nitrogen gas atmosphere at 23 ° C., the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured. Was used as an index of life as half-life time (τ0.5). For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner.

[Drive voltage]
The voltage at the start of light emission was measured at a temperature of 23 ° C. and in a dry nitrogen gas atmosphere. Note that the voltage value at the start of light emission was measured when the luminance was 50 cd / m ² or more. A spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used for measuring the luminance.

[High temperature storage]
The produced organic EL device was measured in exactly the same manner as the above-described external extraction quantum efficiency after storage at 80 ° C. for 60 hours in a dry nitrogen gas atmosphere. (External extraction quantum efficiency after high temperature storage) / (External extraction quantum efficiency) was calculated and used as high temperature storage stability.

  The measurement results of the external extraction quantum efficiency, emission lifetime, drive voltage, and high-temperature storage stability of the organic EL elements 1-1 to 1-17 are the results of relative evaluation when the organic EL element 1-17 is 100. It is shown in 2.

  The polymer compound according to the present invention is excellent in external extraction quantum efficiency, light emission lifetime, drive voltage, and high-temperature storage stability, and is clearly an electron transport material particularly excellent in high-temperature storage stability.

Example 2
<< Preparation of organic EL element 2-5 >>
A transparent substrate provided with this ITO transparent electrode after patterning was performed on a substrate (NH-Techno Glass NA-45) in which ITO (indium tin oxide) was formed to a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

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

  On this hole transport layer, a solution prepared by dissolving 40 mg of HS-117 and 2 mg of PD-1 in 3 ml of dehydrated mesitylene was formed by spin coating at 1000 rpm for 30 seconds. Heat-dried at 150 degreeC for 1 hour, and provided the light emitting layer with a film thickness of 40 nm.

  On this light emitting layer, a solution (dope) of 15 mg of PCz-13 and 3 mg of cesium fluoride (alkali metal compound) dissolved in 3 ml of dehydrated 1,1,1,3,3,3-hexafluoroisopropanol was added at 1000 rpm. The film was formed by spin coating under the condition of 30 seconds. Heat-dried at 120 ° C. for 1 hour to provide an electron transport layer having a thickness of 20 nm.

This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. Aluminum 110nm was vapor-deposited and the cathode was formed, and the organic EL element 2-5 was produced.

<< Preparation of organic EL elements 2-1 to 2-4 and 2-6 to 2-15 >>
In the production of the organic EL element 2-5, the organic EL elements 2-1 to 2-4 and 2-6 were exactly the same except that the material used for the electron transport layer was changed to the compounds shown in Table 3 below. ~ 2-15 were prepared.

  In Table 3, POXD and AcAc have the following structures.

<< Evaluation of Organic EL Elements 2-1 to 2-15 >>
Evaluation of the obtained organic EL elements 2-1 to 2-15 was performed in the same manner as in the case of the organic EL element 1-1 described above. The measurement results of the external extraction quantum efficiency, emission lifetime, drive voltage, and high-temperature storage stability of the organic EL elements 2-1 to 2-15 are the results of relative evaluation when the organic EL element 2-15 is 100. 4 shows.

  Even in the above-described element configuration, it is clear that the electron transport material according to the present invention is excellent in external extraction quantum efficiency, light emission lifetime, and high-temperature storage stability. Furthermore, when the electron transport material according to the present invention is doped with an alkali metal compound or an alkaline earth metal compound, a decrease in driving voltage is recognized, and it can be used more suitably.

Example 3
<< Production of Organic EL Element 3-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning was performed on a substrate (NH-Techno Glass NA-45) in which ITO (indium tin oxide) was formed to a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

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

  On this hole transport layer, a solution prepared by dissolving 40 mg of BH-19 and 2 mg of PD-1 in 3 ml of dehydrated mesitylene was formed by spin coating at 1000 rpm for 30 seconds. Heat-dried at 150 degreeC for 1 hour, and provided the light emitting layer with a film thickness of 40 nm.

  On this light emitting layer, a solution prepared by dissolving 15 mg of PCz-13 in 3 ml of dehydrated 1,1,1,3,3,3-hexafluoroisopropanol was formed by spin coating at 1000 rpm for 30 seconds. A first electron transport layer having a thickness of 20 nm was provided. Further, 1 mg of cesium fluoride was dissolved in 2 ml of dehydrated methanol, a film was formed by spin coating under a condition of 5000 rpm for 30 seconds, and the upper part of the first electron transport layer was doped with cesium fluoride. An electron transport layer was formed.

It heat-dried at 120 degreeC for 1 hour, this was attached to the vacuum evaporation system, and the vacuum vessel was pressure-reduced to 4x10 <^-4> Pa. Aluminum 110nm was vapor-deposited, the cathode was formed, and the organic EL element 3-1 was produced.

  In the same procedure as described above, when the organic EL element 2-15 was set to 100, the external extraction quantum efficiency, the light emission lifetime, the drive voltage, and the high temperature storage stability were evaluated, and the results were 110, 1020, 94, and 320, respectively. there were. From this, it can be seen that it can be suitably used by any manufacturing method, such as mixing into an electron transport material solution when forming an electron transport layer, or post-doping after forming an electron transport layer.

Example 4
<< Preparation of Organic EL Element 4-1 >>
A transparent substrate provided with this ITO transparent electrode after patterning was performed on a substrate (NH-Techno Glass NA-45) in which ITO (indium tin oxide) was formed to a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode. The supporting substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

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

On this positive hole transport layer, the solution which melt | dissolved 20 mg PCz-1 and 2 mg PD-1 in 2 ml of toluene was formed into a film by the spin coat method on 1500 rpm and 30 second conditions. Heat-dried at 120 ° C. for 1 hour to provide a light-emitting layer having a thickness of 40 nm. This was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa.

  Next, ET-8 (bis (2-methyl-8-quinolate) -p-phenylphenolate aluminum complex; BAlq) was deposited as an electron transport layer at 30 nm, lithium fluoride at 1 nm as a cathode buffer layer, and aluminum at 110 nm as a cathode. Then, a cathode was formed, and an organic EL element 4-1 was produced.

<< Production of Organic EL Elements 4-2 to 4-5 >>
In the production of the organic EL element 4-1, the organic EL elements 4-2 to 4-5 were exactly the same except that the PCz-1 and PD-1 used in the light emitting layer were changed to the compounds shown in Table 5 below. Was made.

  Measurement of the external extraction quantum efficiency, light emission lifetime, drive voltage, and high-temperature storage stability of the organic EL elements 4-1 to 4-5 was performed in exactly the same manner as described above. The results are shown by relative evaluation when the organic EL element 4-5 is 100. The results are shown in Table 6.

  Even when the polymer compound according to the present invention is used as a host compound in the light emitting layer, it is clear that the external extraction quantum efficiency, the light emission lifetime, the driving voltage, and the high temperature storage stability are excellent.

Example 5
<Production of full-color display device>
(Blue light emitting organic EL device)
A blue light-emitting organic EL element 1-6B was produced in the same manner as in the production of the organic EL element 1-6 described in Example 1, except that PD-1 was changed to PD-12.

(Green light-emitting organic EL device)
The organic EL element 1-6 produced in Example 1 was used as a green light-emitting organic EL element.

(Red light emitting organic EL device)
In the production of the organic EL element 1-6 of Example 1, a red light emitting organic EL element 1-6R was produced in the same manner except that PD-1 was changed to PD-10.

  The above red, green and blue light emitting organic EL elements are juxtaposed on the same substrate to produce an active matrix type full color display device having the form shown in FIG. 1, and FIG. 2 shows a display portion of the produced display device. Only the schematic diagram of A is shown. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate, and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) 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 lattice shape and are connected to the pixels 3 at the orthogonal positions ( Details are 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. Thus, a full color display device was produced by juxtaposing the red, green, and blue pixels appropriately.

  It was confirmed that by driving the full-color display device, a full-color moving image display having a high light emission efficiency and a long light emission life can be obtained.

Example 6
《Preparation of white light emitting lighting device》
In the production of the organic EL element 1-6 produced in Example 1, white light emitting organic EL element 1-6W was produced in the same manner except that PD-1 was changed to PD-1, PD-10, PD-12. did.

  The obtained organic EL element 1-6W was covered with a glass case on the non-light emitting surface in the same manner as in Examples 1 and 2 to obtain a lighting device. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 107 Glass substrate with a transparent electrode 106 Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catcher

Claims (9)

An organic electroluminescent element material comprising a polymer compound represented by the following general formula (1).

(Formula (1) _X 1 ~X ₇ in represents N atom or CR group, R represents a hydrogen atom or a substituent. _However, a single N atoms of X 1 to X _4, and / _or, one of X 5 to X ₇ is N atom, the other is CR group. Further, _{X 1} and _X 2, _{X 2} and _X 3, _{X 3} and _X 4, _{X 6} and _{X 7} Are simultaneously CR groups, R may be bonded to each other to form a 5-membered or 6-membered aromatic ring, where n represents the average degree of polymerization, and 3 ≦ n ≦ 1000.   Furthermore, 0.01-50 mass% of alkali metal compounds or alkaline-earth metal compounds are contained with respect to the high molecular compound represented by the said General formula (1), The organic electroluminescence of Claim 1 characterized by the above-mentioned. Element material.   An organic electroluminescence device having at least an organic layer between opposing electrodes, wherein the organic layer has the organic electroluminescence device material according to claim 1.   The organic electroluminescence device according to claim 3, wherein the organic layer is an electron transport layer. The organic layer is composed of a plurality of layers, one of which is a light emitting layer, and a compound represented by the following general formula (2) is included as a host compound. Organic electroluminescence device.
Formula ₍₂₎ L n -Q _m
(Wherein L is a condensed aromatic heterocyclic ring which may be substituted, Q is an optionally substituted aromatic hydrocarbon ring or aromatic heterocyclic ring, and n and m are each an integer of 1 to 3) L may be different from each other when n is 2 or more, and Q may be different from each other when m is 2 or more.) The organic electroluminescence device according to claim 5, wherein L of the compound represented by the general formula (2) is represented by the following general formula (3).

(In the formula, A represents an O atom, an S atom, and an NR ₉ group. R _{1 to} R ₉ represent a hydrogen atom or a substituent.)   The organic electroluminescence device according to claim 3, which emits white light.   A display device comprising the organic electroluminescence element according to claim 3.   The illuminating device provided with the organic electroluminescent element of any one of Claims 3-7.

Images