JPWO2010044342A1 - ORGANIC ELECTROLUMINESCENT ELEMENT, METHOD FOR PRODUCING ORGANIC ELECTROLUMINESCENT ELEMENT, WHITE ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE AND LIGHTING DEVICE - Google Patents

Abstract

Provided are an organic electroluminescence element having a high external extraction quantum efficiency, a long emission lifetime, and a low driving voltage, a white organic electroluminescence element including the element, a display device, and an illumination device.

Description

  The present invention relates to an organic electroluminescence element, a method for producing an organic electroluminescence element, a white organic electroluminescence element, a display device, and an illumination device.

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

  On the other hand, an organic EL element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. This is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when this 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. , Nature, 395, 151-154 (1998), since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

  In addition, recently discovered organic EL devices that use phosphorescence can realize a luminous efficiency that is approximately four times that of previous devices that use fluorescence. 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.

  Although this is a very high potential method, the organic EL device using phosphorescence emission is greatly different from the organic EL device using fluorescence emission, and the method for controlling the position of the emission center, particularly the emission layer, is particularly different. An important technical issue in capturing the efficiency and lifetime of the device is how to recombine inside to stably emit light.

  Therefore, in recent years, a multilayer stacked device having a hole transport layer (located on the anode side of the light emitting layer) and an electron transport layer (located on the cathode side of the light emitting layer) adjacent to the light emitting layer is better. (For example, refer nonpatent literature 1).

  In particular, when using blue phosphorescence, since the excited triplet energy of the blue phosphorescent material itself is large, development of peripheral materials and precise control of the emission center are strongly demanded.

  On the other hand, due to demands for large area, low cost, and high productivity, there is a great expectation for the wet process, and in particular, vacuuming in electrode film formation is strongly demanded. In addition, since the film can be formed at a low temperature as compared with the film formation by the vacuum process, damage to the lower 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 conductive paste material. A cathode forming method by coating film formation (for example, see Patent Document 2) has been reported.

  As described above, in the organic EL element using blue phosphorescence emission, in order to realize wet film formation including from the organic layer to the cathode, an adjacent electron transport material becomes a problem, from a practical viewpoint, Currently known electron transport materials are still insufficient in terms of solution stability, driving voltage, and the like, and further improvement techniques are indispensable.

JP 2005-285732 A JP 2005-514729 A

Organic EL Handbook P-198, Realize Science Center, published in 2004

  An object of the present invention is to provide an organic electroluminescence element having a high external extraction quantum efficiency, a long emission lifetime, and a low driving voltage, a white organic electroluminescence element including the element, a display device, and an illumination device. That is.

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

1. In a phosphorescent organic EL device having an organic layer sandwiched between an anode and a cathode,
It has an electron transport layer adjacent to the cathode as a constituent layer of the organic layer, and the electron transport layer is formed through a step of forming a film by a wet method and contains a low molecular weight compound or a non-conjugated high molecular weight compound An organic electroluminescence device, wherein the cathode is formed through a step of forming a film by a wet method using a conductive paste.

  2. 2. The organic electroluminescence device as described in 1 above, wherein the low molecular weight compound is a compound represented by the following general formula (1).

General formula (1)
Qm-Ln
[In the formula, L represents a condensed aromatic heterocyclic ring, Q represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and n and m each represent 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. ]
3. 3. The organic electroluminescence device according to 2 above, wherein L of the compound represented by the general formula (1) has a partial structure represented by the following general formula (2).

[Wherein, A represents -O-, -S- or -N (R1)-, and A11 to A18 each represent a nitrogen atom or -C (R2)-. R1 and R2 each represent a bond, a hydrogen atom or a substituent. However, when -C (R2)-is plural, each -C (R2)-may be the same or different. ]
4). 4. The organic electroluminescence device as described in 2 or 3 above, wherein the compound represented by the general formula (1) has at least one pyridine ring as a partial structure.

  5. 5. The organic electroluminescence device according to any one of 1 to 4, wherein the conductive paste contains at least one selected from a conductive compound dispersion and a low melting point metal compound.

  6). 6. The organic electroluminescence device as described in 5 above, wherein the conductive compound dispersion is a metal nanoparticle dispersion.

  7). Any one of 1 to 6 above, wherein the interface between the electron transport layer and the cathode contains an alkali metal, an alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound. The organic electroluminescent element of description.

  8). 8. The organic electroluminescence according to any one of 1 to 7 above, wherein the conductive paste contains an alkali metal, an alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound. element.

  9. 9. The organic electroluminescence according to any one of 1 to 8, wherein the electron transport layer contains an alkali metal, an alkaline earth metal, a compound of the alkali metal, or a compound of the alkaline earth metal. element.

  10. A phosphorescent light-emitting layer as a constituent layer, the light-emitting layer is adjacent to the electron transport layer, and the light-emitting layer contains at least a phosphorescent dopant and a light-emitting host; 10. The organic electroluminescence device according to any one of 1 to 9, wherein the dopant is a compound represented by the following general formula (A).

[Wherein, Q1 represents a 5-membered or 6-membered aromatic ring. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R3 and R4 represent a hydrogen atom or a substituent. k represents an integer of 2 or 3, and has m secondary ligands L so as to satisfy the valence of iridium. ]
11. 11. The organic electroluminescent device as described in 10 above, wherein the phosphorescent light emitting layer contains the compound represented by the general formula (1) as a light emitting host.

  12 In manufacturing the organic electroluminescence device according to any one of 1 to 11, the step of applying and forming the electron transport layer by a wet method, and then applying the cathode by a wet method using a conductive paste -The manufacturing method of the organic electroluminescent element characterized by having the process of forming into a film.

  13. 13. The method for producing an organic electroluminescent element as described in 12 above, wherein the conductive paste contains an alkali metal, an alkaline earth metal, a compound of the alkali metal or a compound of the alkaline earth metal.

  14 A film is formed by a wet method using a mixed solution or mixed dispersion of the compound represented by the general formula (1) and an alkali metal, alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound. 13. The method for producing an organic electroluminescence device as described in 12 above, further comprising a step of forming an electron transport layer and then a step of forming a cathode film by a wet method using a conductive paste.

  15. A step of forming an electron transport layer by forming a film by a wet method using a coating liquid or dispersion containing the compound represented by the general formula (1), then alkali metal, alkaline earth metal, and the alkali metal And a step of impregnating the electron transport layer with a solution or dispersion containing the above compound or the alkaline earth metal compound, followed by a step of forming a cathode by a wet method using a conductive paste. 13. The method for producing an organic electroluminescence device according to 12 above.

  16. A white organic electroluminescence device comprising the organic electroluminescence device according to any one of 1 to 11 above.

  17. A display device comprising the organic electroluminescence element according to any one of 1 to 11 or the white organic electroluminescence element according to 16.

  18. 14. An illumination device comprising the organic electroluminescence element according to any one of 1 to 11 or the white organic electroluminescence element according to 16.

  According to the present invention, there are provided an organic electroluminescence element having a high external extraction quantum efficiency, a long emission lifetime, and a low driving voltage, a white organic electroluminescence element including the element, a display device, and an illumination device. did it.

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.

  In the compound for organic EL devices of the present invention, by having the configuration according to any one of claims 1 to 11, organic electroluminescence having a high external extraction quantum efficiency, a long light emission lifetime, and a low driving voltage. A luminescence element could be provided.

  In addition, it was possible to provide a method for producing the element, a white light emitting organic electroluminescence element, a display device, and a lighting device.

  Hereinafter, the detail of each component of the organic electroluminescent element of this invention is demonstrated sequentially.

  The organic EL device of the present invention is a phosphorescent organic EL device having an organic layer sandwiched between an anode and a cathode as described in claim 1, and the cathode is used as a constituent layer of the organic layer. The electron transport layer is formed through a process of forming a film by a wet method, contains a low molecular weight compound or a non-conjugated high molecular weight compound, and the cathode is conductive. It is an organic electroluminescence device that exhibits the effects described in the present invention (high external extraction quantum efficiency, long light emission lifetime, low driving voltage, etc.) by being formed through a process that uses a paste to form a film by a wet method. .

  The cathode constituting the organic EL device of the present invention is formed by a wet process using a conductive paste, and an electron transport layer adjacent to the cathode (the cathode, anode, electron transport layer, etc. are described later) The film is also formed by a wet method.

  Here, the wet method will be described in detail in the method of manufacturing the organic EL element.

<Low molecular weight compound>
The low molecular weight compound according to the present invention will be described.

  The low molecular weight compound according to the present invention refers to a compound having a value of 2,000 or less, which is obtained by directly measuring a molecular relative mass (synonymous with molecular weight) by mass spectrometry. Mass spectrometry uses ionization methods such as EI, CI, FD, FAB, MALDI, ESI, etc., magnetic field deflection type, quadrupole type, ion trap type, time of flight (TOF) type, etc. Generally well-known analysis methods based on these separation methods can be used.

  The low molecular weight compound according to the present invention is preferably a compound represented by the above general formula (1), and more preferably a compound represented by any one of the following general formulas (3) to (99).

  In the compound represented by the general formula (1) or the compound represented by any one of the general formulas (3) to (99), the condensed aromatic heterocyclic ring represented by L is 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 the carboline ring replaced by a nitrogen atom), phenanthroline ring, dibenzofuran ring, dibenzothiophene ring, naphthofurene ring, naphthothiophene ring , Benzodifuran ring, benzodithiophene ring, naphtho Furan ring, naphthodifuran thiophene ring, Antorafuran ring, anthradithiophene furan ring, anthracite thiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, such as thio fan train ring (naphthothiophene ring).

  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 (1) or the compound represented by any one of the general formulas (3) to (99), the aromatic hydrocarbon ring represented by Q includes a benzene ring, a biphenyl ring, and 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, coronene ring, fluorene ring, Examples include 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 anthrathrene ring.

  Furthermore, these rings may have a substituent described later.

  In the compound represented by the general formula (1) or the compound represented by any one of the general formulas (3) to (99), the aromatic heterocycle represented by Q includes a furan ring, a thiophene ring, and an 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, diazacarbazole ring (one of the carbon atoms constituting the carboline ring is In addition, a ring substituted with a nitrogen atom is shown. ), 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 (1) based on this invention has the partial structure represented by the said General formula (2).

  In -C (R2)-represented by -N (R1)-represented by A in formula (2) and represented by A11 to A18, the substituents represented by R1 and R2 are each an alkyl group. (For example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl) Group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (eg, Ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, Phenyl group, p-chlorophenyl group, mesityl group, tolyl 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 (the carbolinyl group) Any one of the carbon atoms constituting the carboline ring is substituted with a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (eg, a pyrrolidyl group, an imidazolidyl group, a morpholyl group, an oxazolidyl group, etc.), an alkoxy group (For example, methoxy group, Xy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (for example, phenoxy group, Naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), Arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxy group) Xycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexyl) Aminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propyl group) Carbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbo Group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (eg, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide Groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group) , Phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylamino group) Bonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group Ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group), sulfinyl group ( For example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfuric group Finyl group, phenylsulfinyl group, naphthylsulfinyl 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 heteroarylsulfonyl 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 (for example, fluorine atom, chlorine atom, bromine atom, etc.), Fluorinated hydrocarbon groups (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, trimethyl group) Isopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.) and phosphono group.

  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.

  In addition, the compound represented by the general formula (1) according to the present invention preferably has at least one pyridine ring as a partial structure.

  Hereinafter, specific examples of the compound preferably used as the low molecular weight compound according to the present invention will be shown, but the present invention is not limited thereto.

  Low molecular weight compounds according to the present invention are 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).

《Non-conjugated high molecular weight compound》
The nonconjugated high molecular weight compound according to the present invention will be described.

  The non-conjugated high molecular weight compound according to the present invention refers to a compound having a number average molecular weight (Mw) of 1,000 or more in terms of standard polystyrene using a molecular weight measurement method using size exclusion chromatography (SEC). A preferred molecular weight (Mw) is 1,000 to 1,000,000 for use in organic EL applications.

  As SEC, GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a column solvent can be used, and a generally known GPC device for molecular weight measurement can be used.

  Before describing the non-conjugated high molecular weight compound according to the present invention, first, the conjugated polymer will be described.

  Here, the conjugated system is a general term for molecular systems in which π electrons of multiple bonds are delocalized due to repetition of multiple bonds and single bonds. Particularly, conjugated polymers are polyp-phenylene, polyacetylene, etc. A polymer material in which the polymer main chain mainly forms a conjugated system.

  In contrast, a non-conjugated polymer refers to a polymer material in which the polymer main chain does not mainly form a conjugated system (non-conjugated), such as polystyrene that does not have multiple bonds in the main chain or a polymer in which the main chain conjugated system is interrupted. m-phenylene etc. are mentioned.

  The low molecular weight compound and the non-conjugated high molecular weight compound according to the present invention are preferably used as an electron transport material constituting the electron transport layer of the organic EL device of the present invention, but in other organic layers of the organic EL device of the present invention. It may be contained.

  Hereinafter, although the specific example of the nonconjugated high molecular weight compound which concerns on this invention is given, this invention is not limited to these.

  The non-conjugated high molecular weight compound according to the present invention can be synthesized with reference to known methods described in the above-mentioned description relating to the synthesis of low molecular weight compounds and polymer synthesis / reaction (edited by the Society of Polymer Science). .

  The low molecular weight compound and the non-conjugated high molecular weight compound according to the present invention are preferably used as an electron transport material constituting the electron transport layer of the organic EL device of the present invention, but in other organic layers of the organic EL device of the present invention. It may be contained.

《Conductive paste》
The cathode (the cathode, anode, organic layer, etc. will be described in detail later) constituting the organic EL device of the present invention is formed by a wet method using a conductive paste.

  The conductive paste according to the present invention preferably contains a conductive compound dispersion or a low melting point metal compound.

here,
(A) A conductive compound dispersion refers to a liquid material in a state where a conductive compound is dispersed in a liquid such as water or an organic solvent. Examples of the conductive compound include metals and conductive polymer materials, and either an inorganic compound or an organic compound may be used. The conductive compound is preferably used in a fine particle state (particle size is 1 nm to 10 μm) in order to facilitate the formation of a dispersion. As the organic solvent, generally well-known solvents such as hydrocarbon solvents and fluorine-containing solvents can be appropriately used.

  In the present invention, the conductive compound dispersion is preferably a metal nanoparticle dispersion. Here, the metal nanoparticle dispersion refers to a solution in which metal nanoparticles having an average particle diameter of 1 nm to 100 nm are suspended in a solvent.

  In the solution, a dispersion stabilizer, a protective agent and the like may be mixed in order to prevent re-aggregation of metal nanoparticles. In addition, the viscosity and the like can be adjusted by selecting the metal nanoparticle concentration and the type of solvent in accordance with the purpose of use and apparatus specifications.

  Examples of the metal species of the metal nanoparticles according to the present invention include Ag, Au, Cu, Pd, Sn, In, Co, Bi, Al, Zn, and the like.

  Regarding the production of Al nanoparticles, it is also possible to refer to the AIST press release “Technology for printing metal electrodes on plastic films at low temperatures” on September 24, 2008.

  (B) The low melting point metal compound refers to an alloy having a melting point of 100 ° C. or lower, and the low melting point alloy is classified into an alkali metal type and other types depending on the use and handling. Alkali metal is an alloy between alkali metals, and NaK is known. However, since it reacts violently with air and water, it is mainly used as a heat medium in a sealed state. In the present invention, various alloys mainly containing zinc, indium, gallium, tin, bismuth, lead, etc. other than alkali metal are preferred.

  For example, solder that is an alloy of tin, galinstan that is a gallium alloy (composition is gallium 68.5%, indium 21.5%, tin 10%), wood metal that is a bismuth alloy (composition is 50% bismuth, lead 26 0.7%, tin 13.3%, cadmium 10%) and the like, and the melting point can be changed by changing the composition ratio of the alloy.

In the present invention,
(C) The conductive paste preferably contains an alkali metal, alkaline earth metal, alkali metal compound or alkaline earth metal compound.

  The alkali metal according to the present invention represents 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 according to the present invention represents 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 represent a salt, a complex, an oxide, or the like containing the alkali metal or alkaline earth metal element.

  In the present invention, an alkali metal, an alkaline earth metal, a compound of the alkali metal or a compound of the alkaline earth metal is preferably contained at the interface between the electron transport layer and the cathode adjacent to the cathode.

  As an aspect thereof, the cathode contains an alkali metal, an alkaline earth metal, the alkali metal compound or the alkaline earth metal compound, or the electron transport layer contains an alkali metal, an alkaline earth metal, or the alkali metal. Or a compound of the alkaline earth metal.

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

  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.

  In the phosphorescent organic EL device of the present invention, at least the cathode and the electron transport layer adjacent to the cathode are applied and formed by a wet method.

  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 these layers are formed, 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 nm to 200 nm, and a desired organic EL device is 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 anode as + and the cathode as-. 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 it 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 / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode << light emitting layer >>
The light emitting layer according to the present invention 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 thickness of the light emitting layer is not particularly limited, but 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 2 nm-200 nm, More preferably, it adjusts to the range of 5 nm-100 nm.

  The light emitting layer of the organic EL device of the present invention preferably contains at least one of a light emitting host compound and a light emitting dopant as a guest material, and preferably contains a phosphorescent dopant described later as the light emitting dopant.

  Moreover, it can mention as an example of a preferable aspect that a light emitting host compound and 3 or more types of light emission dopants are contained as a light emitting layer of the organic EL element of this invention.

  A host compound (also referred to as a light-emitting host) and a light-emitting dopant (also referred to as a light-emitting dopant compound) included in the light-emitting layer are described below.

(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 defined as a compound of less than 0.1.

  The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in a layer is 20% or more among the compounds contained in a light emitting layer.

  The compound represented by the general formula (1) 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 organic EL element can be made highly efficient.

  Moreover, it becomes possible to mix different light emission by using multiple types of light emission dopants mentioned later, and, thereby, arbitrary luminescent colors can be obtained.

  The 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 the 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 becoming longer, 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.

  Hereinafter, although the specific example of the compound which may be used together as a host compound of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

(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 (also referred to as phosphorescent emitter, phosphorescent compound, phosphorescent compound, etc.) as the luminescent dopant according to the present invention. To do.

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

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

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

  There are two types of light emission of phosphorescent dopants in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent dopant. Energy transfer type to obtain light emission from the phosphorescent dopant, and the other is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and the phosphorescent dopant In any case, the excited state energy of the phosphorescent dopant is required to be lower than the excited state energy of the host compound.

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

  The phosphorescent dopant according to the present invention 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 compounds), rare earth complexes, and most preferred are iridium compounds.

  As the phosphorescent dopant according to the present invention, a compound represented by the above general formula (A) is preferably used.

<< phosphorescent dopant represented by formula (A) >>
The phosphorescent dopant represented by the general formula (A) according to the present invention will be described.

  In the general formula (A), the 5-membered or 6-membered aromatic ring represented by Q1 includes a benzene ring, an oxazole ring, an isoxazole ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, and a pyrimidine ring. , Pyrazine ring, diazine ring, triazine ring, imidazole ring, pyrazole ring, triazole ring and the like.

  The above ring may further form a condensed ring and may have a substituent.

  In the general formula (A), the aromatic hydrocarbon group and the aromatic heterocyclic group represented by Ar are -N (R1)-represented by A in the general formula (2) and A11 to A18, respectively. In -C (R2)-represented by each, it is synonymous with the aromatic hydrocarbon group and aromatic heterocyclic group which are mentioned as an example of the substituent represented by R1 and R2, respectively.

  In the general formula (A), the substituents represented by R3 and R4 are each represented by -N (R1)-represented by A in the general formula (2), or A11 to A18, and -C (R2 )-Has the same meaning as the substituents represented by R 1 and R 2.

  In the general formula (A), as the secondary ligand L, oxycarboxylic acid, oxyaldehyde and derivatives thereof (for example, salicylaldehyde, oxyacetophenonate, etc.), dioxy compounds (for example, biphenolate, etc.), diketones ( For example, acetylacetonato, dibenzoylmethanato, diethylmalonate, ethylacetoacetate, etc.), oxyquinones (eg, pyromeconato, oxynaphthoquinato, oxyanthraquinato, etc.), tropolones (eg, troponato, hinokitiolato, etc.) , N-oxide compounds, aminocarboxylic acids and similar compounds (eg, glycinato, alaninato, anthranilate, picolinato, etc.), hydroxylamines (eg, aminophenolato, ethanolaminato, mercaptoethylaminato, etc.), oxines ( For example, 8-oxyquinolinato etc.), aldimines (eg salicylaldiminato etc.), oximes (eg benzoin oximato, salicylaldoximato etc.), oxyazo compounds (eg oxyazobenzonat, phenylazonaphtholato) ), Nitrosonaphthols (for example, β-nitroso-α-naphtholate, etc.), triazenes (for example, diazoaminobenzenato, etc.), biurets (for example, biuretate, polypeptide group, etc.), formazenes and dithizones ( For example, diphenylcarbazonate, diphenylthiocarbazonate, etc.), piguanides (for example, piguanidate, etc.), glyoximes (for example, dimethylglyoximato, etc.) and the like can be mentioned.

  Various known ligands may also be used, for example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin in 1987, “Organometallic Chemistry-Fundamentals and Applications-” Liu Huabo Company, Akio Yamamoto, published in 1982, etc. (for example, halogen ligands (preferably chlorine ligands), Nitrogen heterocyclic ligands (for example, bipyridyl, phenanthroline, etc.) and diketone ligands).

  Hereinafter, although the specific example of a compound represented by general formula (A) which concerns on this invention as a phosphorescent dopant is shown, this invention is not limited to these.

  Moreover, 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 below 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 having a function of transporting electrons and a very small ability to transport holes. By blocking the holes, the probability of recombination of electrons and holes can be improved.

  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 according to 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 an electron at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

  (1) Keywords using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), which is molecular orbital calculation software manufactured by Gaussian, USA. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the 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 by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

  On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense, and is made of a material that has a function of transporting holes and has an extremely small ability to transport electrons, and transports electrons while transporting holes. By blocking, the 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 transport layer according to the present invention is preferably 3 nm to 100 nm, and more preferably 5 nm 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 from the viewpoint of obtaining a light emitting element with higher efficiency.

  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 nm-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, 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.

  Also, 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), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga, or Pb can also be used as an electron transport material.

  In addition, metal-free or metal phthalocyanine, 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 nm-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, the use of such an n-type electron transport layer is preferably used from the viewpoint of producing a device with lower power consumption.

  Hereinafter, although the specific example of the compound (electron transport material) preferably used together for formation of the electron carrying layer of the white 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, the film thickness is preferably in the range of 10 nm to 1000 nm, more preferably in the range of 10 nm to 200 nm, although it depends on the material.

"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.

  In the present invention, these electrode substances (also referred to as conductive materials) are used as a conductive paste to form a thin film by a wet method to produce a cathode.

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

"substrate"
As a substrate (hereinafter also referred to as a base, a base material, a support substrate, a support, etc.) that can be used in the organic EL device according to the present invention, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. Or opaque. 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 Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

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, oxygen permeation measured by a method according to JIS K 7126-1987. The film is preferably a high barrier film having a degree of 10 ⁻³ ml / (m ² · 24 h · MPa) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) 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, a vacuum deposition method, a sputtering method, a reactive sputtering method, a molecular beam epitaxy method, a cluster ion beam method, an ion plating method, a plasma polymerization method, an atmospheric pressure plasma polymerization method. A plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque 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 according to 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 used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

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

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

  In the present invention, a polymer film and a metal film can be preferably used because the 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, sputtering, reactive sputtering, molecular beam epitaxy, cluster ion beam, ion plating, plasma polymerization, atmospheric pressure plasma A combination 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 is also possible. 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, etc. used for the sealing can be used. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. 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 according to 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, A method of forming a diffraction grating between any layers of the transparent 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 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 and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

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

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

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

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

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

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

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm.

  If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

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

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

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

<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.

  When patterning is performed only on the light emitting layer, the method is not limited, but preferred examples include a vapor deposition method, an ink jet method, a spin coating method, and a printing method.

  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 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. The present invention is not limited to these examples.

  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 held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

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

  FIG. 4 is a schematic 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.

  Further, 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 for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display).

  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 emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those combined with a dye material that emits light may be used, but in the white organic EL device according to the present invention, only a combination of a plurality of light emitting dopants may be 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 or the like is not necessary. 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 device of the present invention is covered with a glass case, a glass substrate having a thickness of 300 μm is used as a sealing substrate, and an epoxy-based photocurable adhesive (LUX TRACK manufactured by Toagosei Co., Ltd.) is used as a sealing material. LC0629B) is applied, and this is overlaid on the cathode and brought into close contact with 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 a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in the sealing operation with the glass cover, the organic EL element 101 is brought into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

  FIG. 6 shows a cross-sectional view of the lighting device. In FIG. 6, 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. The structural formulas of the compounds used in the examples are shown below.

Example 1
《Solution stability during preparation of coating solution》
When preparing the coating solution for Alq ₃ , BCP, PBD, BAlq and the compound (11 types) according to the general formula (1) of the present invention, which are materials used as the constituent material of the electron transport layer of the organic electroluminescence device of the present invention. The solution stability of was evaluated.

  The test sample and solvent combinations are shown in Table 1.

  The solvent is selected from five general solvents shown in Table 1 based on the solvent classification such as nonpolar aliphatic hydrocarbon, nonpolar aromatic hydrocarbon, polar aprotic, polar protic, and fluorine. I went there.

  A 10 mg test sample was weighed, 1 ml of solvent was added, and the mixture was stirred at room temperature with a magnetic stirrer. After stirring for 30 minutes, when an insoluble matter could be visually confirmed, the mixture was heated and stirred at 50 ° C. for 30 minutes.

  When visually inspected again and insoluble matter could be confirmed, the mixture was stirred under heating until dissolved under reflux conditions for a maximum of 2 hours.

  With respect to those dissolved under the above conditions, solution stability as an electron transport material was evaluated.

  The evaluation conditions were a purity measurement by HPLC (High Performance Liquid Chromatography) before and after standing at 25 ° C. for 24 hours.

Measuring device name: High performance liquid chromatograph LC-2000Plus series (manufactured by JASCO Corporation)
Column: GL Science Co., Ltd. Inert sill SIL-100A (4.6Φx250mm)
Measurement conditions: Toluene / cyclohexane mixed solvent system (50 / 50-30 / 70)
Evaluation was performed by the following rank evaluation.

○: Change rate (P24 / P0) is less than 1% Δ: Change rate (P24 / P0) is 1% or more and less than 5% ×: Change rate (P24 / P0) is 5% or more It represents purity, and P24 represents the purity after 24 hours.

  The obtained results are shown in Table 1.

  From Table 1, it can be seen that the solution prepared using the compound represented by the general formula (1) according to the present invention exhibits very excellent solution stability.

  In particular, the compounds of Sample Nos. 1 to 11 are soluble in a plurality of solvent systems and exhibit high solution stability. all right.

On the other hand, it can be seen that aluminum complexes such as Alq ₃ and BAlq, which are well known as electron transport materials, have very poor stability in solution.

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

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then 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-16 and 2 mg of ID-4 in 2.5 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 of 30 mg HS-69 and 3 mg cesium fluoride dissolved in 6 ml of dehydrated 1,1,1-3,3,3-hexafluoroisopropanol was spun at 1000 rpm for 30 seconds. A film was formed by a coating method. Heat-dried at 120 ° C. for 1 hour to provide an electron transport layer having a thickness of 20 nm.

  Further, 20 ml of silver nanoparticle paste dispersion (MDot-SL, manufactured by Mitsuboshi Belting Co., Ltd.) was ejected and patterned using an inkjet head (manufactured by Epson; MJ800C), then baked at 120 ° C. for 5 minutes under nitrogen, A 110 nm silver cathode was formed to produce an organic EL device 1-1.

<< Production and Evaluation of Organic EL Element 1-2 and Organic EL Element 1-3 >>
In the production of the organic EL element 1-1, the organic EL element 1- was prepared in the same manner except that Poly-1 which is a non-conjugated polymer electron transporting material was used instead of HS-69 used for the electron transport layer. 2 and the organic EL device 1-3 was produced in the same manner except that the cathode was directly formed without providing the electron transport layer on the light emitting layer.

  Using an organic EL element evaluation method to be described later, relative evaluation was performed by setting the external quantum efficiency (also referred to as light emission efficiency), the light emission lifetime, and the driving voltage of the organic EL element 1-1 to 100, respectively. The external quantum efficiency, the light emission lifetime, and the drive voltage in 2 are 105, 60, and 95, respectively, and the external quantum efficiency, the light emission lifetime, and the drive voltage in the organic EL element 1-3 are 80, 1, and 170, respectively. Each of the organic EL elements 1-1 and 1-2 having an excellent performance as compared with the organic EL element 1-3 having no electron transporting layer has an electron transport property in the phosphorescent organic EL element. It is clear that the layer has an important role.

Example 3
<< Manufacture of organic EL element 2-1 >>
After patterning on a substrate (NH-Techno Glass NA-45) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

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

  5 mg of HT-24 and 10 mg of HT-26 were dissolved in 3 ml of dehydrated toluene, and a film was formed by spin coating using this solution under conditions of 1000 and 30 seconds.

  UV irradiation (100 W UVA, 200 mJ) for 15 seconds under nitrogen, photopolymerization / crosslinking, heat drying at 120 ° C. for 10 minutes, and insolubilization treatment by polymerizing polymerizable groups, film thickness 20 nm The second hole transport layer was formed.

  On this second hole transport layer, a solution prepared by dissolving 40 mg of BH-16 and 2 mg of ID-4 in 2.5 ml of dehydrated mesitylene was formed by spin coating at 1000 rpm for 30 seconds. Heat-dried at 1 degreeC for 1 hour, and provided the 40 nm-thick luminescent layer.

  On this light emitting layer, a solution prepared by dissolving 30 mg of HS-70 in 6 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.

  A solution prepared by dissolving 20 mg of potassium fluoride in 1 ml of methanol is dropped on the electron transport layer, spin coating is initially performed at 100 rpm for 10 seconds, and then immediately at 3000 rpm for 30 seconds. Potassium halide immersion was performed.

  Further, 20 ml of silver nanoparticle paste dispersion (MDot-SL, manufactured by Mitsuboshi Belting Co., Ltd.) was ejected and patterned using an inkjet head (manufactured by Epson; MJ800C), and then baked at 120 ° C. for 5 minutes under nitrogen. A 110 nm silver cathode was formed to produce an organic EL device 2-3.

<< Manufacture of organic EL elements 2-2 to 2-4 >>
In the production of the organic EL element 2-1, the organic EL elements 2-2 to 2-4 were made in exactly the same manner except that the light emitting dopant used in the light emitting layer and the electron transport layer were changed as shown in Table 2. Each was manufactured.

<< Evaluation of Organic EL Elements 2-1 to 2-4 >>
When evaluating the obtained organic EL elements 2-1 to 2-4, 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 sealing material, 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 to form an illumination device as shown in FIGS. 5 and 6, and the external extraction quantum efficiency, light emission lifetime, and driving voltage were evaluated. Moreover, the conditions in each evaluation item are shown below.

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

<Luminescent 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. The half-life time (τ ^0.5 ) was used as an index of life. In addition, the spectral radiance meter CS-1000 (made by Minolta) was similarly used for the measurement.

<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. In addition, the voltage value at the time of the light emission start voltage was measured when the luminance became 50 cd / m ² or more. A spectral radiance meter CS-1000 (manufactured by Minolta) was used for the measurement of luminance.

  The obtained results are shown in Table 2. In addition, relative evaluation was performed by setting the external quantum efficiency, light emission lifetime, and driving voltage of the organic EL element 2-4 to 100, and Table 2 shows the results.

  From Table 2, when the organic EL element 2-1 using phosphorescence emission is compared with the organic EL element 2-3 using fluorescence emission, the difference in element performance is clear. The superiority of the light emitting device is clear.

  Further analysis of the results shows that the presence or absence of the electron transport layer greatly affects the physical properties of the organic EL element when compared between the organic EL elements 2-1 and 2-2.

  Furthermore, in 2-3 (with an electron transport layer) and 2-4 (without an electron transport layer) using a fluorescent light-emitting dopant, the effect of the present invention obtained by providing an electron transport layer (high external extraction quantum efficiency) It is clear that the electron transport layer is indispensable in the organic EL device using phosphorescence emission since the long emission lifetime and the low driving voltage are lower than those using the phosphorescence emission dopant. It is.

Example 4
<< Production of Organic EL Element 3-8 >>
After patterning on a substrate (NH-Techno Glass NA-45) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then 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-16 and 2 mg of ID-4 in 2.5 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 of 30 mg of HS-42 dissolved in 6 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.

  Furthermore, 200 mg of sodium fluoride is dissolved in 5 ml of methanol, and slowly added so as not to agglomerate, 20 mg of silver nanoparticle paste dispersion (MDot-SL manufactured by Mitsuboshi Belting Ltd.), and a conductive compound having an alkali metal compound The dispersion was adjusted.

  After discharging and patterning the above dispersion using an inkjet head (manufactured by Epson; MJ800C), baking was performed at 120 ° C. for 5 minutes under nitrogen to form a silver cathode having a thickness of 110 nm. Manufactured.

<< Manufacture of organic EL elements 3-1 to 3-7 and 3-9 to 3-24 >>
In the organic EL element 3-8, the organic EL elements 3-1 to 3-7 and 3 were similarly changed except that the constituent material of the electron transport layer (also referred to as an electron transport material) was changed as shown in Table 3. 9-3-24 were produced respectively.

  At the time of production, in the production of the organic EL elements 3-22 and 3-24, the lower light emitting layer flowed out when the electron transport layer was applied, and the element could not be produced.

  Further, in the organic EL element 3-23, the sample No. As shown in FIG. 12, the solution stability of ET-8 (BAlq) was extremely poor, and the device could not be manufactured.

<< Evaluation of Organic EL Elements 3-1 to 3-24 >>
The element evaluation of the organic EL elements 3-1 to 3-24 was performed in exactly the same manner as the element evaluation method described in Example 2.

  In the evaluation, the external quantum efficiency, the light emission lifetime, and the driving voltage of the organic EL element 3-21 were set as 100, and the relative evaluation was performed. The results are shown in Table 3.

  In addition, evaluation was not performed about the organic EL elements 3-22, 3-23, and 3-24 which were not able to manufacture an element.

  The results obtained are shown in Table 3 below.

  From Table 3, the organic EL device of the present invention in which the compound represented by the general formula (1) according to the present invention is contained in the electron transport layer as an electron transport material has a high external extraction quantum efficiency and a long emission lifetime. It is also clear that the driving voltage is low.

  On the other hand, BAlq, which has been well known as an electron transport material, has very poor stability in solution, and it is understood that an electron transport layer cannot be formed by the wet method.

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

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then 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-16 and 2 mg of ID-4 in 2.5 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 of 30 mg of HS-42 dissolved in 6 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.

  20% by mass of the GaIn (Ga: In 15% by mass: 85% by mass) alloy obtained above in a liquid alloy of GaInSn (Ga: In: Sn 62% by mass: 25% by mass: 13% by mass) The mixture was allowed to stand for 6 hours and then stirred to form a paste, and further stirred at 120 ° C. for 10 minutes to prepare a low melting point metal paste.

  The obtained paste was set in a dispenser, discharged and patterned while heating to 100 ° C., a cathode was formed, and an organic EL element 4-1 was manufactured.

<< Manufacture of organic EL element 4-2 >>
In the production of the organic EL element 4-1, the organic EL element 4-2 was produced in exactly the same manner except that the cathode was directly formed without providing the electron transport layer on the light emitting layer.

  The obtained organic EL device was evaluated in the same manner as described in Example 2.

  When the relative evaluation was performed by setting the external quantum efficiency, the light emission lifetime, and the drive voltage of the organic EL element 4-1 to 100, the external quantum efficiency, the light emission lifetime, and the drive of the organic EL element 4-2 lacking the electron transport layer. The voltages were 69, 5, and 200, respectively, and the importance of the electron transport layer in the phosphorescent organic EL device became clear.

Example 6
<Production of full-color display device>
(Blue light emitting organic EL device)
The organic EL element 2-1 described in Example 2 was used.

(Green light-emitting organic EL device)
A green light-emitting organic EL element 2-1G was produced in the same manner as in the organic EL element 2-1 produced in Example 2, except that ID-4 was changed to PD-1.

(Red light emitting organic EL device)
A red light-emitting organic EL element 2-1R was produced in the same manner as in the organic EL element 2-1 produced in Example 2, except that ID-4 was changed to PD-10.

  The 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 the display of the produced display device. Only the schematic diagram of part 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.

  In this way, a full color display device was produced by appropriately juxtaposing the red, green, and blue pixels.

  It was confirmed that by driving the full-color display device, a full-color moving image display having a high external quantum efficiency (also referred to as light emission efficiency) and a long light emission lifetime can be obtained with a low drive voltage.

Example 7
《Preparation of white light emitting lighting device》
A white light-emitting organic EL element 2-1W was produced in the same manner as in the production of the organic EL element 2-1 of Example 2, except that ID-4 was changed to PD-1, PD-10, and ID-4.

  Similarly, the obtained organic EL element 2-1W was covered with a glass case on a non-light-emitting surface to obtain a lighting device. The lighting device can be used as a thin white light emitting lighting device that emits white light having a low driving voltage, high external quantum efficiency (also referred to as light emission efficiency), and a long light emission lifetime.

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 (18)

In a phosphorescent organic EL device having an organic layer sandwiched between an anode and a cathode,
It has an electron transport layer adjacent to the cathode as a constituent layer of the organic layer, and the electron transport layer is formed through a step of forming a film by a wet method and contains a low molecular weight compound or a non-conjugated high molecular weight compound An organic electroluminescence device, wherein the cathode is formed through a step of forming a film by a wet method using a conductive paste. The organic electroluminescence device according to claim 1, wherein the low molecular weight compound is a compound represented by the following general formula (1).
General formula (1)
Qm-Ln
[In the formula, L represents a condensed aromatic heterocyclic ring, Q represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and n and m each represent 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 2, wherein L of the compound represented by the general formula (1) has a partial structure represented by the following general formula (2).

[Wherein, A represents -O-, -S- or -N (R1)-, and A11 to A18 each represent a nitrogen atom or -C (R2)-. R1 and R2 each represent a bond, a hydrogen atom or a substituent. However, when -C (R2)-is plural, each -C (R2)-may be the same or different. ] The organic electroluminescence device according to claim 2 or 3, wherein the compound represented by the general formula (1) has at least one pyridine ring as a partial structure. The organic electroluminescent element according to claim 1, wherein the conductive paste contains at least one selected from a conductive compound dispersion and a low melting point metal compound. The organic electroluminescence device according to claim 5, wherein the conductive compound dispersion is a metal nanoparticle dispersion. The alkali metal, alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound is contained at the interface between the electron transport layer and the cathode. The organic electroluminescent element of description. The said electroconductive paste contains an alkali metal, an alkaline earth metal, this alkali metal compound, or this alkaline earth metal compound, The organic electro of any one of Claims 1-7 characterized by the above-mentioned. Luminescence element. The organic electro according to claim 1, wherein the electron transport layer contains an alkali metal, an alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound. Luminescence element. A phosphorescent light-emitting layer as a constituent layer, the light-emitting layer is adjacent to the electron transport layer, and the light-emitting layer contains at least a phosphorescent dopant and a light-emitting host; The organic electroluminescent element according to any one of claims 1 to 9, wherein the dopant is a compound represented by the following general formula (A).

[Wherein, Q1 represents a 5-membered or 6-membered aromatic ring. Ar represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and R3 and R4 represent a hydrogen atom or a substituent. k represents an integer of 2 or 3, and has m secondary ligands L so as to satisfy the valence of iridium. ] The organic electroluminescence device according to claim 10, wherein the phosphorescent light-emitting layer contains the compound represented by the general formula (1) as a light-emitting host. When manufacturing the organic electroluminescent element of any one of Claims 1-11, the process by which an electron carrying layer is apply | coated and formed into a film by a wet method, Then, a cathode is made into a wet method using a conductive paste. The manufacturing method of the organic electroluminescent element characterized by having the process of apply | coating and film-forming. 13. The method of manufacturing an organic electroluminescence element according to claim 12, wherein the conductive paste contains an alkali metal, an alkaline earth metal, a compound of the alkali metal, or a compound of the alkaline earth metal. A film is formed by a wet method using a mixed solution or mixed dispersion of the compound represented by the general formula (1) and an alkali metal, alkaline earth metal, the alkali metal compound, or the alkaline earth metal compound. The method for producing an organic electroluminescence element according to claim 12, further comprising a step of forming an electron transporting layer, and then a step of forming a cathode by a wet process using a conductive paste. A step of forming an electron transport layer by forming a film by a wet method using a coating liquid or dispersion containing the compound represented by the general formula (1), then alkali metal, alkaline earth metal, and the alkali metal And a step of impregnating the electron transport layer with a solution or dispersion containing the above compound or the alkaline earth metal compound, followed by a step of forming a cathode by a wet method using a conductive paste. The manufacturing method of the organic electroluminescent element of Claim 12 to do. A white organic electroluminescent element comprising the organic electroluminescent element according to claim 1. A display device comprising the organic electroluminescence element according to any one of claims 1 to 11 or the white organic electroluminescence element according to claim 16. An illuminating device comprising the organic electroluminescent element according to any one of claims 1 to 11 or the white organic electroluminescent element according to claim 16.