JP2012169199A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an organic electroluminescent element suppressing leakage faults of organic electroluminescent elements, improved in luminance half-life and decreased in drive voltage.SOLUTION: An organic electroluminescent element includes an anode and cathode, and a plurality of organic functional layers sandwiched between the both electrodes, on a substrate. In the organic electroluminescent element, each of the organic functional layers has at least a luminous layer, and also has an insulation layer in contact with the anode formed on the substrate.

Description

  The present invention relates to an organic electroluminescence element, and more particularly to an organic electroluminescence element in which leakage failure is suppressed, half-luminance life is improved, and driving voltage is lowered.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. As a constituent element of ELD, an inorganic electroluminescence element (hereinafter also referred to as an inorganic EL element) and an organic electroluminescence element (hereinafter also referred to as an organic EL element) can be given. Inorganic EL 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 electroluminescence device has a structure in which a light emitting layer containing a light emitting compound is sandwiched between a cathode and an anode, and excitons (exciton) are injected by injecting electrons and holes into the light emitting layer and recombining them. ), Which emits light by using light emission (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several V to several tens of V, and further self-emission. Since it is a type, 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, portability, and the like.

  As a method for producing an organic electroluminescence device, there are a vapor deposition method and a wet process (spin coating method, casting method, ink jet method, spray method, printing method, etc., hereinafter also referred to as a coating method), but a continuous vacuum process is not required. In recent years, wet process production has attracted attention because it is simple to produce.

In the coating type organic EL device, a hole injection / transport material which is an aqueous polymer material such as PEDOT / PSS is preferably used from the viewpoint of hole injection and transportability. However, deactivation of excitons due to moisture and diffused substances such as S or SO ₃ from PEDOT has been a problem. Moreover, although ITO is often used for the anode, deactivation of excitons due to diffusion of indium ions has also been a problem (see, for example, Non-Patent Document 1).

Organic EL handbook, published by Realize Science and Technology Center, 2004, p260

  Accordingly, an object of the present invention is to obtain an organic electroluminescence device in which leakage failure of the organic electroluminescence device is suppressed, the half-luminance lifetime is improved, and the driving voltage is lowered.

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

  1. In an organic electroluminescent element having an anode, a cathode, and a plurality of organic functional layers sandwiched between both electrodes on a substrate, the plurality of organic functional layers have at least a light-emitting layer, and are on the substrate. An organic electroluminescence element comprising an insulating layer in contact with the formed anode.

  2. 2. The organic electroluminescence device according to 1 above, wherein the insulating layer has a thickness of 1 to 10 nm.

  3. 3. The organic electroluminescence device as described in 1 or 2 above, wherein the insulating layer is formed of a polyolefin-based polymer.

  4). 3. The organic electroluminescence element as described in 1 or 2 above, wherein the insulating layer is made of a fluorine-based polymer material.

  According to the present invention, an organic electroluminescence device having no leakage failure, improved half-luminance lifetime, and reduced driving voltage was obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the coating type electroluminescent element which the issue lifetime improved can be provided. By providing at least one insulating layer without providing the water-based hole injection layer on the anode, it was possible to provide a device with improved half-luminance life.

  In the coating type organic EL element, from the viewpoint of hole injection and transportability, for example, a hole injection / transport material which is an aqueous polymer material such as PEDOT / PSS is preferably used. No hole injection material has been found.

Among the problems related to ensuring the reliability of elements, it is essential to prevent leakage current. In general, an organic electroluminescence element in a good state shows a characteristic with a rectification ratio of about 10 ^−5, but when a leak current is generated, the rectification ratio is greatly reduced. The leak current causes heat generation, and easily destroys the organic electroluminescence element using an organic substance that is weak against heat. In the case of manufacturing a display panel using an organic electroluminescence element, the presence of leakage current causes crosstalk and becomes a fatal defect for the display panel.

  From the investigation in the present invention, it has also been found that such a hole injection layer has a role of avoiding a leak failure. As a result of repeated investigations to avoid leakage failure without using a coating type hole injection layer, for example, a layer made of a hole injection / transport material which is a water-based polymer material such as PEDOT / PSS, an insulator is formed on the anode. It has been found that by providing an insulating layer instead, a leakage failure can be avoided while realizing a desired driving voltage, and further the life can be improved.

The material for forming the insulating layer is not particularly limited as long as it is an insulator. Here, the insulator is a specific resistance (resistivity) of 10 ⁸ Ωcm at room temperature (25 ° C.) and humidity of 50% RH. The material which is the above is said. Although an organic material or an inorganic material may be used, an organic material is preferable because most of the organic material is an insulator and can be easily formed by coating.

  Among organic materials, a polymer material is preferable, it does not transmit a diffused substance that causes moisture and deterioration, a polymer material such as a polyolefin polymer such as polyethylene and polypropylene, polyvinylidene fluoride (PVDF), tetrafluoroethylene-hexa Fluorine polymer materials such as polyolefin fluorinated polymers such as fluoropropylene copolymers are preferred. For example, a fluorinated polymer represented by the following formula described in JP-A-2004-99607 is also exemplified.

2,2,3,3,4,5-hexafluoro-2,3-dihydrofuran polymer, 2,2,3,3,4,5-hexafluoro-2,3-dihydrofuran and others at least one polymerizable monomer, for _{example, CF 2 = CHCF (CF 3} ) CF 2 OCF = CF 2, or polymers obtained by copolymerizing a fluoroolefin such as tetrafluoroethylene and the like.

  Other fluoropolymer materials include fluorinated polymers described in JP-A-6-3808, polymers of perfluoro-2,2-dimethyl-1,1-dioxole, and other fluoroolefins and fluorovinyl ethers. And a fluorinated polymer obtained by copolymerization.

  The polymerization degree of the polymer material is not particularly limited as long as it is in the range of 10 to 10,000, but is preferably 10 to 1,000 from the viewpoint of solubility in a solvent during film formation.

  The specific resistance value is determined by the four probe method according to JIS-R-1637. In addition, for example, Mitsubishi Chemical Loresta-GP and MCP-T600 can be used for the measurement.

  Increasing the film thickness is a simple method for flattening the unevenness caused by particles adhering to the anode surface or the surface thereof. However, in order to completely avoid leakage using a material having a carrier transport capability, it is necessary to stack a certain amount of film thickness, and it is difficult to obtain a desired driving voltage.

  The insulating layer preferably has a thickness of 1 to 10 nm. Within this range, carrier injection is not disturbed, and the unevenness caused by the surface of the anode and particles adhering to the surface can be flattened, thereby preventing leakage.

By providing an insulating layer of 10 nm or less, carrier injection is not hindered by the tunnel effect while flattening unevenness and edges due to particles. Furthermore, the deactivation of excitons due to moisture and diffused substances such as S or SO ₃ from PEDOT can be suppressed. When the thickness is 1 nm or more, it becomes easy to flatten the edges due to unevenness and particles.

  As the insulating layer according to the present invention, any material may be used as long as it satisfies the conditions. In general, a fluorine-substituted organic compound is relatively easy to obtain a material having a high water repellent effect. Therefore, it is preferable. In particular, the use of a fluorinated polymer is most preferable because it suppresses crystallinity and easily forms a transparent amorphous film.

  As for the fluorinated polymer, for example, I-1 used in Examples, 2,2,3,3,4,5-hexafluoro-2,3 according to the method described in JP-A-2004-99607. -It can be produced by copolymerizing a dihydrofuran monomer with tetrafluoroethylene.

<< 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 / insulating layer / hole transporting layer / light emitting layer / electron transporting layer / cathode (ii) Anode / insulating layer / hole injection layer / hole transporting layer / light emitting layer / electron transporting layer / cathode (iii) Anode / insulating layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (iv) Anode / insulating layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (v) ) Anode / insulating layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode Among these layers, the layers excluding the anode, the cathode and the intermediate layer are collectively referred to as an organic functional layer. Say.

  Each layer will be described below.

<Light emitting layer>
The light-emitting layer 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. May be an interface between the light emitting layer and the adjacent layer, but is preferably within the layer of the light emitting layer because of deactivation of excitons between layers.

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

  A host compound (also referred to as a light emitting host) and a light emitting dopant contained in the light emitting layer will be described below.

《Host compound》
The host compound used in the present invention will be described.

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

  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.

  Although the specific example of a host compound is shown below, it is not limited to these.

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

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

《Light emitting dopant》
The light emitting dopant according to the present invention will be described.

  As the light-emitting dopant according to the present invention, a fluorescent dopant or a phosphorescent dopant can be used. From the viewpoint of obtaining an organic EL element with higher luminous efficiency, light emission used in the light-emitting layer or light-emitting unit of the organic EL element. As a dopant, it is preferable to contain a phosphorescent dopant simultaneously with 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 compound). Rare earth complexes, most preferably iridium compounds.

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

<Injection layer: electron injection layer>
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).

  Regarding the hole injection layer, for example, a hole injection layer using a hole injection / transport material which is a water-based polymer material such as PEDOT / PSS is not necessarily required, but may be provided as necessary.

  The details of the hole injection layer (anode buffer layer) are also 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.

  Further, it is generally often used to dope the polymer buffer layer with an acid such as polystyrene sulfonic acid (PSS) in order to improve conductivity. However, there is a concern that impurities such as doped acid diffuse inside the device due to heating, voltage application, etc., and adversely affect device performance.

  Although there is no restriction | limiting in particular in the film thickness of a positive hole injection layer, It is preferable to adjust to the range of 2-200 nm from a viewpoint of the homogeneity of the film | membrane to form, More preferably, it adjusts to the range of 5-100 nm.

  The electron injection layer may be provided as necessary, and may be present between the cathode and the light emitting layer or the electron transport layer.

  The details of the electron injection layer (cathode buffer layer) are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. .

  The injection layer (buffer 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.

  It is conceivable that the stability of the device over time is deteriorated due to the diffusion of impurities in the injection layer. However, when an azacalixarene derivative or the like is used as the suppression means, the performance is improved.

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

  The hole blocking layer has a function of an electron transport layer in a broad sense, and is made of a hole blocking material that has a function of transporting electrons and has a remarkably small ability to transport holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

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

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

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

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

《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.

  It is also possible to use a so-called p-type hole transport material as described in JP-A No. 11-251067 and literature (Applied Physics Letters 80 (2002), p. 139 J. Huang et. Al.). it can. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

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

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

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

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material.

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

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

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

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

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

  For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

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

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

  The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

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

"substrate"
As a substrate (hereinafter also referred to as a support substrate) that can be used in the organic EL element of the present invention, there is no particular limitation on the type of glass, plastic and the like, and it may be 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 Polyetherimide, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, acrylic or polyarylates, and cycloolefin resins such as ARTON (manufactured by JSR) or APEL (manufactured by Mitsui Chemicals).

An inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film, and a barrier film having a water vapor permeability of 0.01 g / (m ² · 24 h) or less is preferable. Furthermore, the oxygen permeability is 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less (1 atm is 1.01325 × 10 ⁵ Pa), and the water vapor permeability is 10 ⁻⁵ cm ³ / (m ² · 24 h. -It is preferable that it is a high barrier film below atm).

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

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

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

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

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

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

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

In the present invention, a polymer film and a metal film can be preferably used because the organic EL element can be thinned. Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. was measured by the method, the water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) is preferably those 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.

  There are no particular limitations on the method of forming these films. 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 can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

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

<< Method for producing organic EL element >>
The organic EL device production method of the present invention is preferably formed by a wet process from the viewpoint of productivity. The wet process referred to in the present invention is to form a layer by supplying a layer forming material in the form of a solution when forming a layer.

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

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

  Next, organic compound thin films (organic layers) such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are organic EL element materials, are formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, die coating method, casting method, ink jet method, spray method, printing method) as described above. Further, in the present invention, it is preferable to form a film by a coating method such as a spin coating method, a die coating method, an ink jet method, a spray method, or a printing method because a homogeneous film is easily obtained and pinholes are hardly generated. .

  When the organic EL device of the present invention is produced by a wet process, examples of the liquid medium for dissolving or dispersing the material include ketones such as methyl ethyl ketone, cyclohexanone, cyclopentanone, and 2-pentanone, ethyl acetate, butyl acetate, and the like. Fatty acid esters, halogenated hydrocarbons such as dichlorobenzene, aromatic hydrocarbons such as toluene, xylene, mesitylene, cyclohexylbenzene, and anisole, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, DMF, DMSO, etc. Organic solvents or water can be used.

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

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

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

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

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

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

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

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

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

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

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

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

  As described above, the position where the diffraction grating is introduced may be in any one of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the light emitting layer where light is generated. At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

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

<Condenser sheet>
The organic EL device of the present invention can be processed to provide, for example, a microlens array-like structure on the light extraction side of the substrate, or combined with a so-called condensing sheet, for example, in a specific direction, for example, the device light emitting surface. On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.

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

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, Sumitomo 3M brightness enhancement film (BEF) can be used. As the shape of the prism sheet, for example, a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 μm may be formed on the substrate, the vertex angle may be rounded, and the pitch may be 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.

When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X = 0 when the 2 ° viewing angle front luminance is measured by the above method. .33 ± 0.07, Y = 0.33 ± 0.1. 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.

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

  Moreover, the structure of the compound used in the Example is shown below.

Example 1
<< Production of Organic EL Element 101 >>
After patterning a 100 mm × 100 mm × 1.1 mm glass substrate made of ITO (Indium Tin Oxide) 100 nm as an anode, the transparent support substrate provided with the ITO transparent electrode was superposed with normal propyl alcohol. Sonic cleaning, drying with dry nitrogen gas, and UV ozone cleaning were performed for 5 minutes.

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

  Next, the substrate was moved to a glove box under a nitrogen atmosphere, and spin coating (film thickness of about 20 nm) was performed at 1500 rpm for 30 seconds using a solution in which compound HT-2 (50 mg) was dissolved in 10 ml of monochlorobenzene. And dried under nitrogen at 160 ° C. for 30 minutes to form a hole transport layer.

  Furthermore, spin coating (film thickness of about 40 nm) was performed at 1500 rpm for 30 seconds using a solution in which Compound H-27 (73 mg) and Compound D-1 (14 mg) were dissolved in 10 ml of isopropyl acetate. It dried under nitrogen for 30 minutes and was set as the light emitting layer.

  Next, spin coating (film thickness of about 20 nm) was performed at 1500 rpm for 30 seconds using a solution in which compound ET-1 (50 mg) was dissolved in 10 ml of 2,2,3,3-tetrafluoropropanol. And dried for 30 minutes under nitrogen to obtain an electron transport layer.

The substrate is attached to a vacuum deposition apparatus, the vacuum chamber is depressurized to 4 × 10 ⁻⁴ Pa, LiF is deposited as an electron injection layer at 2 nm, then aluminum 110 nm is deposited to form a cathode, and the organic EL element 101 is formed. Produced.

<< Production of Organic EL Element 102 >>
In the production of the organic EL element 101, spin coating was performed at 5000 rpm for 60 seconds using a solution in which 20 mg of polyethylene (PE) was dissolved in 10 ml of chlorobenzene without providing a hole injection layer, and 150 ° C., 30 An organic EL element 102 was produced in the same manner except that the insulating layer having a thickness of 10 nm was formed by heating under nitrogen for 5 minutes.

<< Production of Organic EL Element 103 >>
In the production of the organic EL device 103, a film obtained by dissolving 60 mg of polyethylene (PE) in 10 ml of chlorobenzene was spin-coated at 5000 rpm for 60 seconds, heated at 150 ° C. for 30 minutes under nitrogen, and a film thickness of 30 nm. The organic EL element 103 was produced in the same manner except that the insulating layer was used.

<< Production of Organic EL Elements 104 and 105 >>
In the production of the organic EL element 103, 20 mg and 60 mg of polyvinylidene fluoride (PVDF) are used instead of polyethylene (PE) in 2,2,3,3,3-pentafluoropropyl-1,1,2,2-tetrafluoroethyl. Using a solution dissolved in 10 ml of ether, spin-coated at 5000 rpm for 60 seconds, and heated under nitrogen at 150 ° C. for 30 minutes to form an insulating layer having a thickness of 10 nm and 30 nm, respectively. Organic EL elements 104 and 105 were produced.

<< Production of Organic EL Elements 106 and 107 >>
In the production of the organic EL element 103, I-1 (20 mg and 60 mg) was dissolved in 10 ml of 2,2,3,3,3-pentafluoropropyl-1,1,2,2-tetrafluoroethyl ether instead of PE. Using the prepared solution, the organic EL element 106 was spin coated in the same manner except that it was spin-coated at 5000 rpm for 60 seconds and heated under nitrogen at 150 ° C. for 30 minutes to form an insulating layer having a thickness of 10 nm and 30 nm, respectively. And 107 were produced.

<< Preparation of Organic EL Element 108 >>
In the production of the organic EL element 103, the organic EL element 108 was produced in the same manner except that the insulating layer was not formed.

<< Evaluation of organic EL elements >>
The following evaluation was performed about the produced organic EL element.

(External quantum efficiency)
The external extraction quantum efficiency (%) when a constant current was applied to the produced organic EL element at ^2.5 mA / cm ² was measured. The external extraction quantum efficiency is calculated by the following equation.

External extraction quantum efficiency (%) = number of photons emitted to the outside of the organic EL element / number of electrons sent to the organic EL element × 100
For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used. The external extraction quantum efficiencies of the organic EL elements 101 to 111 were expressed as relative values with the measured value of the organic EL element 101 (comparative example) as 100. The relative value of the external extraction quantum efficiency is shown in Table 1.

(Half life)
The manufactured organic EL element was continuously driven by applying a current that would give a front luminance of 1000 cd / m ² . The time required for the front luminance to reach the initial half value (500 cd / m ² ) is obtained as a half life, and the half lives of the organic EL elements 102 to 109 are 100 as measured values of the organic EL element 101 (comparative example). It was expressed as a relative value.

(Rectification ratio)
+ 5V (forward direction) and -5V (reverse direction) were applied to the produced organic EL element with a low voltage power source (DC voltage / current source R6243 manufactured by ADC Co., Ltd.), and the current value at that time was measured. The ratio of the reverse current value (forward current value / reverse current value = rectification ratio) was calculated and compared.

(Brightness reduction rate when stored at high temperature)
The front luminance of the organic EL device after being allowed to stand at 75 ° C. for 500 hours was evaluated. Light was emitted at an applied voltage of 5 V, and the luminance reduction rate before storage was evaluated as a relative value when the reduction rate of the organic EL element 101 was 100.

(Dark spot)
The prepared organic EL device was stored in an environment of 60 ° C. and 90% RH for 300 hours and 500 hours, and then a 50 × magnified photograph was taken to visually observe the occurrence of dark spots, according to the following criteria: The dark spot resistance was evaluated.

○: No generation of dark spots was observed even after 500 hours Δ: Generation of dark spots was not observed after storage for 300 hours, but slight generation of dark spots was observed after storage for 500 hours ×: 300 hours Many dark spots are observed even after storage, and the quality is not practical.

  Note that the element 108 was not energized after storage and could not be measured for the luminance reduction rate during storage at high temperatures and for dark spots.

  As shown in Table 1, half-life, rectification ratio, and high-temperature storage can be achieved by applying an intermediate layer with a critical surface tension of 30 mN / m or less between the hole injection layer and the hole transport layer. It can be seen that the brightness reduction rate, dark spots, and the like are improved. Further, it has been clarified that a higher effect is shown by forming the film to 10 nm, and that the effect is more noticeable by using the fluorinated polymer material.

Claims (4)

  In an organic electroluminescent element having an anode, a cathode, and a plurality of organic functional layers sandwiched between both electrodes on a substrate, the plurality of organic functional layers have at least a light-emitting layer, and are on the substrate. An organic electroluminescence element comprising an insulating layer in contact with the formed anode.   The organic electroluminescence element according to claim 1, wherein the insulating layer has a thickness of 1 to 10 nm.   The organic electroluminescence element according to claim 1, wherein the insulating layer is formed of a polyolefin-based polymer.   The organic electroluminescent element according to claim 1, wherein the insulating layer is made of a fluorine-based polymer material.