JP5036660B2 - Method for manufacturing organic electroluminescence device - Google Patents

Description

  The present invention relates to a method for producing an organic electroluminescence element (hereinafter sometimes referred to as “organic EL element” in the present specification) and an organic EL element produced by this method.

  The organic EL element generally has an anode, a cathode, and a light emitting layer sandwiched between them. The light emitting layer is formed of an organic compound that emits light when voltage is applied. The organic EL element is usually produced by laminating a layer constituting an electrode part and a light emitting layer in a predetermined order on a support substrate. As a method for laminating each layer, a method for forming a thin film is used, and one of them is an electron beam evaporation method. In the electron beam evaporation method, accelerated electrons collide with the evaporation material, and the kinetic energy is converted into thermal energy to heat and evaporate the evaporation material to a high temperature, and the evaporated material is solidified on a predetermined substrate to form a thin film. Technology. In the electron beam evaporation method, an evaporation material is irradiated with a high-energy electron beam, and heated directly to evaporate. Therefore, the electron beam evaporation method is suitable for evaporating a deposition material that has been difficult to evaporate in a resistance heating method, such as a substance that reacts with a crucible or the like (Al or the like) or a high melting point substance.

  However, in the electron beam evaporation method, radiation that becomes a damage factor such as secondary electrons, recoil electrons, X-rays, and heat rays is emitted when the electron beam is irradiated onto the evaporation material. By irradiating the organic EL element being formed on the substrate, the organic EL element is damaged, and as a result, the light emission efficiency may be reduced and the drive voltage may be increased. In particular, when the light emitting layer is damaged, the characteristics of the organic EL element such as the light emission efficiency and the lifetime are directly affected, and the characteristics of the organic EL element are deteriorated.

  Various attempts have been made to reduce and ultimately eliminate such damage. For example, an apparatus is disclosed in which a magnet is installed near a substrate or a vapor deposition source so that the substrate is not irradiated with electrons by bending the trajectory of emitted electrons (Patent Documents 1 and 2). Moreover, as a method of suppressing the X-ray dose, a method (Patent Document 3) in which the acceleration voltage of the electron beam is reduced and the amount of emission current is increased, and the shape of the crucible (hearth liner) filling the sample is made into a double structure to provide heat insulation. A method (Patent Document 4) is disclosed in which a sample is heated to the evaporation temperature with a low emission current.

  In addition to attempts to reduce damage that occurs when manufacturing organic EL elements, various studies have been made on element configurations for the purpose of improving the characteristics of organic EL elements. For example, the use of a metal oxide as a layer provided between a light emitting layer and an electrode has been studied, and Patent Document 5 discloses an inorganic oxide layer such as molybdenum oxide between a light emitting layer and an electron injection electrode. It is described to provide.

Japanese Patent Laid-Open No. 11-74221 JP 2000-306665 A Japanese Patent Laid-Open No. 10-158638 Japanese Patent Laid-Open No. 2005-232492 JP 2002-367784 A

  As described above, various attempts have been made to eliminate the harmful effects of the electron beam evaporation method, but it is still not practically sufficient. For example, the method of bending the electron trajectory as described above is useful as a method for removing secondary electrons and recoil electrons, but X-rays cannot be removed and damage to the device due to X-rays should be avoided. I can't. Further, as an electron beam vapor deposition apparatus that does not substantially emit X-rays, an apparatus employing a hollow cathode discharge heating method (HCD) has been disclosed. However, the HCD apparatus is a special apparatus and has a high introduction cost. Further, simply suppressing the acceleration voltage does not necessarily prevent the element from being sufficiently damaged. In addition, the method of making the crucible structure a double structure also causes the apparatus to be complicated and causes an increase in manufacturing cost. Further, when such a crucible is used, the time required to warm the crucible itself becomes long, and a long time is required from the irradiation of the electron beam to the formation of the deposited film.

  When forming an organic EL element, a wet process such as a coating method is often used because of the ease of the process, but the molybdenum oxide layer has low resistance to the wet process, and an organic layer or the like is formed on the molybdenum oxide layer. Is formed by a wet process, the molybdenum oxide layer is damaged, and in some cases, the molybdenum oxide layer may be dissolved in the ink. As described above, in an organic EL element including a molybdenum oxide layer as one of the constituent elements, it is difficult to perform a wet process with an easy process, and it is difficult to improve light emission characteristics and lifetime characteristics of the obtained organic EL element. There's a problem.

  Under the circumstances as described above, the present invention provides a simple method for producing an organic EL element capable of suppressing damage to the organic EL element in the production process, and an organic EL element having a layer structure suitable for the production. Is an issue.

In order to solve the above problems, the present invention provides a manufacturing how the organic EL device having the following configuration.
[1] A method for producing an organic electroluminescent device comprising a first electrode part including an anode, a second electrode part including a cathode, and an organic light emitting layer disposed between the first and second electrode parts. There,
Providing the first electrode portion with a metal-doped molybdenum oxide layer disposed between the anode and the organic light emitting layer;
Providing the metal-doped molybdenum oxide layer;
Of the layers constituting the first and second electrode portions, at least one layer laminated after the organic light emitting layer is formed is represented by the following formulas (1) and (2):
Acceleration voltage x Emission current ÷ Deposition rate <20000 (W · sec / nm) (1)
Acceleration voltage> 4 (kV) (2)
A process of forming by electron beam vapor deposition that satisfies the condition of
The manufacturing method of an organic electroluminescent element containing this.
[2] The method for producing an organic electroluminescent element according to [1], wherein the conditions of the electron beam evaporation further satisfy the following formula (3).
Emission current> 100 (mA) (3)
[3] The method for producing an organic electroluminescence element according to claim 1 or 2, wherein the conditions of the electron beam evaporation further satisfy the following formula (4).
Deposition rate ≧ 1 (nm / sec) (formula 4)
[4] The layers formed by the electron beam evaporation are Al, Zn, In, Ga, Sn, Ni, Cr, Mn, Ti, Mo, Ta, W, Ag, Au, oxides thereof, and nitridation thereof. 1 type or 2 or more types of materials selected from the group consisting of oxides, alkaline earth metals, alkaline earth metal oxides, alkaline earth metal fluorides, alkali metal oxides, and alkali metal fluorides The manufacturing method of the organic electroluminescent element as described in any one of [1] to [3] formed.
[5] The method for producing an organic electroluminescent element according to any one of [1] to [4], wherein the organic light emitting layer is formed of a polymer organic compound.
[6] The organic electroluminescence according to any one of [1] to [5], wherein in the step of providing the metal-doped molybdenum oxide layer, a metal-doped molybdenum oxide layer is provided so as to be in direct contact with the anode. Device manufacturing method.
[7] The method for producing an organic electroluminescent element according to any one of [1] to [6], wherein a layer containing an organic material is formed after the metal-doped molybdenum oxide layer is formed.
[8] The manufacturing of the organic electroluminescence device according to any one of [1] to [7], wherein the step of providing the metal-doped molybdenum oxide layer includes a step of simultaneously depositing molybdenum oxide and a dopant metal. Method.
[9] The method for manufacturing an organic electroluminescent element according to the above [8], further including a step of heating a layer formed by the deposition step after the step of depositing molybdenum oxide and a dopant metal simultaneously.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method which hardly damages the layer which comprises an organic EL element during manufacture is provided.

  When a predetermined layer is formed using a wet process such as a coating method after the inorganic oxide layer is formed, damage to the inorganic oxide layer can be suppressed. An organic EL element can be easily manufactured using a process, and the manufactured organic EL element has good light emission characteristics and lifetime characteristics.

  Moreover, the manufacturing method of the organic EL element which is hard to give the damage in an electron beam vapor deposition process by this invention is provided. The electron beam evaporation process employed in the present invention can be carried out using a general electron beam evaporation apparatus that has already been widely used. In addition, this is a very simple method of adjusting parameters derived from elements to be adjusted when performing electron beam evaporation. According to the manufacturing method of the present invention, the electron beam evaporation process can be completed in a short time. Furthermore, the organic EL device obtained by the production method of the present invention is less likely to be damaged by the electron beam vapor deposition step, and is unlikely to cause a decrease in PL intensity (photoluminescence intensity). Therefore, according to the present invention, the product yield of the organic EL element can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. For ease of understanding, the scale of each member in the drawings may be different from the actual scale. Further, the present invention is not limited by the following description, and can be appropriately changed without departing from the gist of the present invention. In the organic EL device, there are members such as electrode lead wires. However, in the explanation of the present invention, the description is omitted because it is not directly required. For the convenience of explanation of the layer structure and the like, in the example shown below, the explanation is made with the figure in which the substrate is arranged below. However, the organic EL element of the present invention and the organic EL device equipped with the same are necessarily manufactured in this arrangement. Or use etc. are not made. In the following description, one of the substrate in the thickness direction may be referred to as “up” or “up”, and the other in the thickness direction may be referred to as “down” or “down”.

1. Manufacturing method of organic EL device of the present invention The manufacturing method of the organic EL device of the present invention (hereinafter sometimes referred to as “the manufacturing method of the present invention”) includes an electrode portion and a light emitting layer on a supporting substrate. A method of manufacturing an organic EL element by sequentially laminating in a predetermined order, wherein a metal-doped molybdenum oxide layer is provided between an anode and an organic light emitting layer, and an inorganic material layer formed after the formation of the organic light emitting layer is provided. It is formed by an electron beam evaporation method under predetermined conditions.

Hereinafter, the material and forming method of each layer constituting the organic EL element will be described more specifically.
1.1. Substrate The substrate constituting the organic EL device of the present invention may be any substrate that does not change when forming an electrode and forming a layer containing an organic material. For example, glass, plastic, polymer film, silicon substrate, metal plate A laminate of these is used. Further, a plastic, a polymer film or the like that has been subjected to a low water permeability treatment can also be used. A commercially available substrate can be used as the substrate. Moreover, a board | substrate can also be manufactured by a well-known method.

1.2. Formation of the first electrode portion The first electrode portion includes at least an anode and a metal-doped molybdenum oxide layer. In addition to the anode, the first electrode part can be provided with a hole injection layer, a hole transport layer, an electron blocking layer, etc., and the metal-doped molybdenum oxide layer functions as a hole injection layer or a hole transport layer. .

<Anode>
As the anode of the organic EL element, it is preferable to use a transparent electrode that can transmit light because an element that emits light through the anode can be configured. As such a transparent electrode, a metal oxide, metal sulfide or metal thin film having high electrical conductivity can be used, and a material having a high light transmittance can be suitably used, and is appropriately selected depending on the layer containing the organic material to be used. Used. Specifically, a thin film made of indium oxide, zinc oxide, tin oxide, indium tin oxide (Indium Tin Oxide: abbreviated as ITO), indium zinc oxide (Indium Zinc Oxide: abbreviated as IZO), gold, platinum, silver, Copper, aluminum, or an alloy containing at least one of these metals is used. A thin film made of ITO, IZO, or tin oxide is preferably used as the anode because of its high light transmittance and ease of patterning. Examples of the method for producing the anode include a vacuum evaporation method (including an electron beam evaporation method described later), a sputtering method, an ion plating method, a plating method, and the like. Moreover, when providing an anode after organic light emitting layer formation, you may employ | adopt the electron beam vapor deposition method explained in full detail below.

  Further, an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the anode. Also, a thin film made of a mixture containing at least one selected from the group consisting of materials used for the organic transparent conductive film, metal oxides, metal sulfides, metals, and carbon materials such as carbon nanotubes is used for the anode. May be.

  For example, in the case of an element structure in which light is emitted through the cathode, a material that reflects light may be used for the anode, and examples of the material include metals, metal oxides, and metal sulfides having a work function of 3.0 eV or more. preferable.

  The film thickness of the anode can be appropriately selected in consideration of light transmittance and electrical conductivity, and is, for example, 5 nm to 10 μm, preferably 10 nm to 1 μm, and more preferably 20 nm to 500 nm. is there.

<Metal-doped molybdenum oxide layer>

  The metal doped molybdenum oxide layer is provided in the first electrode portion so as to be positioned between the anode and the organic light emitting layer. By adopting molybdenum oxide as a material constituting the inorganic oxide layer in the organic EL element, and further doping the molybdenum oxide with a metal, resistance to a film forming process such as a wet process is improved. The light emission characteristics and lifetime characteristics of the device can be improved.

  The metal-doped molybdenum oxide layer contains molybdenum oxide and a dopant metal, and preferably consists essentially of molybdenum oxide and dopant metal. More specifically, when the metal-doped molybdenum oxide layer is formed as a single layer, the ratio of the total of the molybdenum oxide and the dopant metal in the total amount of the substances constituting the layer is preferably 98% by mass or more, More preferably, it is 99 mass% or more, More preferably, it can be 99.9 mass% or more.

The metal doped molybdenum oxide layer can preferably be provided as a hole injection layer. The metal-doped molybdenum oxide layer may be provided in direct contact with the organic light emitting layer or the hole injection layer. The metal-doped molybdenum oxide layer can be provided, for example, in the following forms (i) to (v).
(I) Provided in contact with the anode and the hole transport layer.
(Ii) Provided in contact with the anode and the electron block layer.
(Iii) It is provided in contact with the hole injection layer and the organic light emitting layer.
(Iv) Provided in contact with the hole injection layer and the electron blocking layer.
(V) Provided in contact with the anode and the organic light emitting layer.

  From the viewpoint of device characteristics, a layer containing a polymer compound can be suitably stacked on the metal-doped molybdenum oxide layer as a layer containing an organic material. Here, “having a layer containing a polymer compound on the metal-doped molybdenum oxide layer“ on ”” means that a metal-doped molybdenum oxide layer is laminated on a certain layer, and further a polymer compound is contained thereon. This refers to the positional relationship in which layers are provided. For example, when a metal-doped molybdenum oxide layer is provided on the anode, it has a layer containing a polymer compound so as to have a positional relationship of anode-metal-doped molybdenum oxide layer-layer containing a polymer compound. means. In many cases, the layer containing a polymer compound is simply provided by a wet process such as an inkjet method. Therefore, by providing a metal-doped molybdenum oxide layer having high resistance to a wet process, the metal-doped molybdenum oxide layer is formed even if a layer to be laminated thereon is further provided by a wet process after the metal-doped molybdenum oxide layer is formed. The damage received can be suppressed, and, for example, the metal-doped molybdenum oxide layer can suitably exhibit the intended function as the hole injection layer.

  The visible light transmittance of the metal-doped molybdenum oxide layer is preferably 50% or more. By having a visible light transmittance of 50% or more, it can be suitably used for an organic EL device that emits light through a metal-doped molybdenum oxide layer.

The dopant metal contained in the metal-doped molybdenum oxide layer is preferably a transition metal, a Group 13 metal of the periodic table, or a mixture thereof, more preferably aluminum, nickel, copper, chromium, titanium, silver, gallium, zinc, Neodymium, europium, holmium, and cerium, and more preferably aluminum. As these dopant metals, the above-mentioned single metals, oxides thereof, alloys of these dopant metals and Mo, and the like can be used. The form of the alloy is not particularly limited, and may take the form of a solid solution alloy, a eutectic alloy, a peritectic alloy, a monotectic alloy, a compound alloy, a mixture alloy, or the like. On the other hand, MoO ₂ and MoO ₃ can be used as the molybdenum oxide _, and preferably MoO ₃ can be adopted. A metal-doped molybdenum oxide layer can be formed by appropriately combining these dopant metals and molybdenum oxide, and preferably a combination of MoO ₃ and a single metal dopant metal can be employed. Note that when MoO ₃ is used as the molybdenum oxide and the film is formed by an evaporation method such as vacuum evaporation, the composition ratio of Mo and O may not be maintained in the deposited film. It can be preferably used.

  The content ratio of the dopant metal to the molybdenum oxide in the metal-doped molybdenum oxide is preferably 0.1 to 20.0 mol%. When the content of the dopant metal is within the above range, good process resistance can be obtained.

  The thickness of the metal-doped molybdenum oxide layer is not particularly limited, but is preferably 10 to 1000 mm.

  A method for forming a metal-doped molybdenum oxide layer is not particularly limited, but a method of obtaining a metal-doped molybdenum oxide layer by simultaneously depositing molybdenum oxide and a dopant metal on another layer constituting the element is preferably exemplified. be able to. Here, the other layer constituting the element may be any layer constituting the organic EL element, and can be appropriately selected according to the production process and the laminated structure of the obtained organic EL element. For example, deposition may be performed on an anode or cathode layer provided on a substrate to form a metal-doped molybdenum oxide layer in direct contact with the electrode. Alternatively, after an electrode is provided on the substrate, one or more other layers such as an organic light emitting layer, a charge injection layer, a charge transport layer, or a charge blocking layer are provided on the electrode, and deposition is further performed thereon. A metal-doped molybdenum oxide layer in direct contact with the substrate may be formed.

  The metal-doped molybdenum oxide layer is resistant to wet processes, the organic light-emitting layer is a polymer material that can be easily formed by a wet process, and the layers constituting the second electrode portion are made of an inorganic material by vapor deposition. In consideration of various conditions such as being capable of being formed, one preferable layer formation order is to form the first electrode portion on one main surface of the substrate, and to form the metal-doped molybdenum oxide layer before forming the organic light emitting layer. In addition, after forming the organic light emitting layer, a process sequence in which an electron injection layer, a cathode, and the like are provided by an electron beam evaporation method under predetermined conditions as described below can be given.

  The material for forming the metal-doped molybdenum oxide layer can be deposited by vacuum evaporation, molecular beam evaporation, sputtering or ion plating, ion beam evaporation, or the like. By introducing plasma into the film formation chamber, a plasma assisted vacuum deposition method with improved reactivity and film formability can be used. Examples of the evaporation source of the vacuum deposition method include resistance heating, electron beam heating, high frequency induction heating, and laser beam heating. As a simpler method, resistance heating, electron beam heating, and high frequency induction heating are preferable. The sputtering method includes a DC sputtering method, an RF sputtering method, an ECR sputtering method, a conventional sputtering method, a magnetron sputtering method, an ion beam sputtering method, an opposed target sputtering method, and any method can be used. In order not to damage the lower layer, it is preferable to use magnetron sputtering, ion beam sputtering, or counter target sputtering. Moreover, when providing a metal dope molybdenum oxide layer after organic light emitting layer formation, you may employ | adopt the electron beam vapor deposition method explained in full detail below. Note that during film formation, vapor deposition can be performed by introducing a gas containing oxygen or an oxygen element into the atmosphere.

The layer formed by depositing as described above can function as a completed metal-doped molybdenum oxide layer as it is. However, after the molybdenum oxide and the dopant metal material are simultaneously deposited as described above, it is preferable to perform heat treatment, UV-O ₃ treatment, atmospheric exposure treatment, and the like as optional steps. By performing these treatments, preferably heat treatment, the resistance of the metal-doped molybdenum oxide layer to the wet process can be further enhanced.

When performing heat processing, it can carry out on the conditions for 1 to 120 minutes at 50-350 degreeC. The UV-O ₃ treatment can be performed by irradiating with ultraviolet rays at an intensity of 1 to 100 mW / cm ² for 5 seconds to 30 minutes and in an atmosphere having an ozone concentration of 0.001 to 99%. The atmospheric exposure treatment can be performed by leaving it in the atmosphere having a humidity of 40 to 95% and a temperature of 20 to 50 ° C. for 1 to 20 days.

  When a member (such as a partition and a layer containing an organic material) is provided by a method including a wet process such as a photolithography method after the metal-doped molybdenum oxide layer is provided, the metal-doped molybdenum oxide layer is highly resistant to the wet process. It is possible to suppress adverse effects such as erosion of the members provided so far. In addition, as a layer containing an organic material, there is at least a light emitting layer, and if another layer described later also contains an organic material, the layer can correspond to a layer containing an organic material.

<Hole injection layer>
When a hole injection layer different from the metal-doped molybdenum oxide layer is provided, the hole injection layer material constituting the hole injection layer is not particularly limited, but a known material can be used as appropriate. Phenylamine, starburst amine, phthalocyanine, hydrazone derivative, carbazole derivative, triazole derivative, imidazole derivative, oxadiazole derivative with amino group, vanadium oxide, tantalum oxide, tungsten oxide, molybdenum oxide, ruthenium oxide, oxidation Examples thereof include oxides such as aluminum, amorphous carbon, polyaniline, and polythiophene derivatives. The thickness of such a hole injection layer is preferably about 5 to 300 nm. If the thickness is less than the lower limit value, the production tends to be difficult. On the other hand, if the thickness exceeds the upper limit value, the driving voltage and the voltage applied to the hole injection layer tend to increase.

<Hole transport layer>
When a hole transport layer different from the metal-doped molybdenum oxide layer is provided, examples of the hole transport layer material constituting the hole transport layer include N, N′-diphenyl-N, N′-di (3- Aromatic amine derivatives such as methylphenyl) 4,4′-diaminobiphenyl (TPD), NPB (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), polyvinylcarbazole or derivatives thereof, Polysilane or derivative thereof, polysiloxane derivative having aromatic amine in the side chain or main chain, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof Derivatives, polypyrrole Examples thereof include a derivative thereof, poly (p-phenylene vinylene) or a derivative thereof, or poly (2,5-thienylene vinylene) or a derivative thereof.

  Among these, as a hole transport material used for the hole transport layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, Polymeric hole transport materials such as polythiophene or derivatives thereof, polyarylamine or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof are preferred, and more preferred Is polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in a side chain or a main chain. In the case of a low-molecular hole transport material, it is preferably used by being dispersed in a polymer binder.

  Although there is no restriction | limiting in the film-forming method of a positive hole transport layer, In the low molecular hole transport material, the method by the film-forming from a mixed solution with a polymer binder is illustrated. In the case of a polymer hole transport material, a method of film formation from a solution is exemplified.

  The solvent used for film formation from a solution is not particularly limited as long as it can dissolve a hole transport material. Examples of the solvent include chlorine solvents such as chloroform, methylene chloride, and dichloroethane; ether solvents such as tetrahydrofuran; aromatic hydrocarbon solvents such as toluene and xylene; ketone solvents such as acetone and methyl ethyl ketone; ethyl acetate, butyl acetate, An ester solvent such as ethyl cellosolve acetate is exemplified.

  Examples of film formation methods from solution include spin coating from solution, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary Coating methods such as coating methods, spray coating methods, nozzle coating methods, etc., gravure printing methods, screen printing methods, flexographic printing methods, offset printing methods, reverse printing methods, printing methods such as inkjet printing methods, etc. may be used. it can. A printing method such as a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reversal printing method, and an inkjet printing method is preferable in that the pattern formation is easy.

  As the polymer binder to be mixed, those not extremely disturbing charge transport are preferable, and those showing no strong absorption against visible light are suitably used. Examples of the polymer binder include polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

  The thickness of the hole transport layer is not particularly limited and can be appropriately changed depending on the intended design, and is preferably about 1 to 1000 nm. If the thickness is less than the lower limit, production tends to be difficult, or the effect of hole transport is not sufficiently obtained. On the other hand, if the upper limit is exceeded, the driving voltage and the hole transport layer are increased. There is a tendency that the voltage applied to the voltage increases. The thickness of the hole transport layer is preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm.

1.3. Light emitting layer The light emitting layer is a layer containing a light emitting material, and the organic light emitting layer is a layer containing an organic compound as the light emitting material. In general, the organic light emitting layer mainly contains an organic substance (low molecular compound and / or high molecular compound) that emits fluorescence or phosphorescence. Further, a dopant material may be further included. Examples of the material for forming the light emitting layer that can be used in the present invention include the following dye-based materials, metal complex-based materials, polymer-based materials, and dopant materials. In the present specification, the polymer has a polystyrene-equivalent number average molecular weight of 10 ³ or more, and usually a polystyrene-equivalent number average molecular weight of 10 ⁸ or less.

<Dye-based material>
Examples of dye-based materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds. Pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, quinacridone derivatives, coumarin derivatives, and the like.

<Metal complex materials>
Examples of the metal complex material include Al, Zn, Be, etc. as a central metal, or rare earth metals such as Tb, Eu, Dy, etc., and oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, as a ligand, Examples include metal complexes having a quinoline structure, such as iridium complexes, platinum complexes and the like, metal complexes having light emission from triplet excited states, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc complexes, benzo Examples include a thiazole zinc complex, an azomethyl zinc complex, a porphyrin zinc complex, and a europium complex.

<Polymer material>
High molecular weight materials include distyrylarylene derivatives, oxadiazole derivatives, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, quinacridone derivatives, coumarin derivatives. And those obtained by polymerizing the above dye-based materials and metal complex-based luminescent materials.

  Among the light-emitting materials, materials that emit blue light include distyrylarylene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, and the like. Of these, polymer materials such as polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives are preferred.

  Examples of materials that emit green light include quinacridone derivatives, coumarin derivatives, and polymers thereof, polyparaphenylene vinylene derivatives, polyfluorene derivatives, and the like. Of these, polymer materials such as polyparaphenylene vinylene derivatives and polyfluorene derivatives are preferred.

  Examples of materials that emit red light include coumarin derivatives, thiophene ring compounds, and polymers thereof, polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Among these, polymer materials such as polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives are preferable.

<Dopant material>
Examples of the dopant material include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, and phenoxazone. In addition, the thickness of such a light emitting layer is usually about 2 nm-200 nm.

<Method for forming light emitting layer>
As a method for forming a light emitting layer containing an organic compound, a method of applying a solution containing a light emitting material on or above a substrate, a vacuum deposition method, a transfer method, or the like can be used. Specific examples of the solvent used for the film formation from the solution include the same solvents as those for dissolving the hole transport material when forming the hole transport layer from the above solution.

  As a method for applying a solution containing a light emitting material on or above a substrate, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method Coating methods such as slit coating method, capillary coating method, spray coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reversal printing method, inkjet printing method, etc. A coating method can be used. A printing method such as a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reversal printing method, and an ink jet printing method is preferable in that pattern formation and multi-coloring are easy. In the case of a sublimable low-molecular compound, a vacuum deposition method can be used. Furthermore, a method of forming a light emitting layer only at a desired place by laser or friction transfer or thermal transfer can also be used.

1.4. Formation of Second Electrode Part The second electrode part includes at least a cathode. In addition to the cathode, the second electrode portion may include an electron injection layer, an electron transport layer, a hole blocking layer, and the like.

<Electron transport layer>
As the electron transport material constituting the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinones or derivatives thereof, tetracyanoanthra Quinodimethane or derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene or derivatives thereof, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof, etc. Illustrated.

  Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinones or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof are preferred, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferable.

  There are no particular restrictions on the method of forming the electron transport layer, but in the case of a low molecular electron transport material, a vacuum deposition method from powder or a method by film formation from a solution or a molten state is used. Each method is exemplified by film formation from a molten state. When forming a film from a solution or a molten state, a polymer binder may be used in combination. Examples of the method for forming an electron transport layer from a solution include the same film formation method as the method for forming a hole transport layer from a solution described above.

  The thickness of the electron transport layer is not particularly limited, but can be appropriately changed according to the intended design, and is preferably about 1 to 1000 nm. If the thickness is less than the lower limit value, it tends to be difficult to produce, or the effect of hole transport cannot be obtained sufficiently. On the other hand, if the thickness exceeds the upper limit value, the driving voltage and the electron transport layer are reduced. The applied voltage tends to increase. The thickness of the electron transport layer is preferably 2 nm to 500 nm, more preferably 5 nm to 200 nm.

<Electron injection layer>
The electron injection layer is provided between the electron transport layer and the cathode or between the light emitting layer and the cathode. Depending on the type of the light emitting layer, the electron injection layer may be an alkali metal or alkaline earth metal, an alloy containing one or more of the above metals, or an oxide, halide and carbonate of the metal, or a mixture of the above substances. Etc. Examples of alkali metals or oxides, halides and carbonates thereof include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, potassium fluoride, rubidium oxide. , Rubidium fluoride, cesium oxide, cesium fluoride, lithium carbonate and the like. Examples of alkaline earth metals or oxides, halides and carbonates thereof include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, barium oxide, barium fluoride, Examples include strontium oxide, strontium fluoride, and magnesium carbonate. Furthermore, a metal, a metal oxide, an organometallic compound doped with a metal salt, an organometallic complex compound, or a mixture thereof can be used for the electron injection layer. The electron injection layer may be a laminate of two or more layers. Specifically, LiF / Ca etc. are mentioned. The electron injection layer is formed by vapor deposition, sputtering, printing, or the like. As a preferred film forming method, an electron beam evaporation method described in detail below can be adopted. The thickness of the electron injection layer is preferably about 1 nm to 1 μm.

<Cathode material>
As a material for the cathode, a material having a small work function and easily injecting electrons into the light emitting layer and / or a material having a high electric conductivity and / or a material having a high visible light reflectance are preferable. As the metal, an alkali metal, an alkaline earth metal, a transition metal, or a group 13 metal of the periodic table can be used. For example, lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, gold, silver, platinum, Copper, manganese, titanium, cobalt, nickel, tungsten, tin, an alloy containing at least one of these metals, graphite, a graphite intercalation compound, or the like is used. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, calcium-aluminum alloy, and the like. Moreover, a transparent conductive electrode can be used as a cathode, for example, a conductive metal oxide, a conductive organic substance, etc. can be used. Specifically, indium oxide, zinc oxide, tin oxide, ITO, IZO may be used as the conductive metal oxide, and an organic transparent conductive film such as polyaniline or a derivative thereof, polythiophene or a derivative thereof may be used as the conductive organic substance. Note that the cathode may have a laminated structure of two or more layers. In some cases, the electron injection layer is used as a cathode.

  The thickness of the cathode can be appropriately selected in consideration of electric conductivity and durability, but is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

  As a method for manufacturing the cathode, a vacuum evaporation method (including the electron beam evaporation method of the above-described embodiment), a sputtering method, a CVD method, an ion plating method, a laser ablation method, a laminating method for pressing a metal thin film, and the like are used. It is done. As a preferable production method, an electron beam evaporation method described in detail below can be adopted.

1.5. Layer Formation Method for Adjusting Deposition Electricity Value In the manufacturing method of the present invention, of the layers constituting one of the first electrode portion and the second electrode portion that are stacked after the organic light emitting layer is formed. At least one layer is formed by electron beam evaporation. In the manufacturing method of the present invention, in the operation of the electron beam deposition apparatus, the electron beam deposition is performed by a very simple method of adjusting a predetermined parameter derived from the three elements of acceleration voltage, emission current, and deposition rate within a certain range. The damage caused by can be greatly reduced. A suitable condition for this is that the acceleration voltage is set higher than a predetermined threshold value, and vapor deposition is performed at a high vapor deposition rate, which is completely unexpected from the conventional knowledge.

  When the first electrode portion, the organic light emitting layer, and the second electrode portion are stacked in this order on the substrate, at least one of the layers constituting the second electrode portion stacked after the organic light emitting layer is formed. Are formed by electron beam evaporation. At that time, electron beam evaporation is performed under the conditions satisfying the following formulas (1) and (2).

Acceleration voltage x Emission current ÷ Deposition rate <20000 (W · sec / nm)
... Formula (1)

  Acceleration voltage> 4 (kV) (2)

  In the production method of the present invention, the parameter derived from the three elements of the acceleration voltage, the emission current, and the deposition rate represented by the formula (1) is smaller than a predetermined value, that is, 20000 (W · sec / nm), more preferably. Is adjusted to 10000 (W · sec / nm) or less. Hereinafter, in the present specification, the numerical value calculated by the left side of the formula (1) is referred to as “deposition power amount value” (unit: W · sec / nm). By setting the deposition power amount value to be equal to or less than such a threshold value, damage to the previously formed layer can be greatly reduced. As is clear from the experimental results shown in the following examples, the damage to the organic light-emitting layer is particularly relieved by adjusting to a value below this value.

  In addition, from the viewpoint of reducing damage to the previously formed layer, it is not necessary to provide a lower limit of the deposition power amount value, but it is possible to suppress significant fluctuations in the deposition rate by making the electron beam more stable. From the viewpoint, it is preferably 50 (W · sec / nm) or more, more preferably 300 (W · sec / nm) or more.

  The adjustment of the deposition power amount value can be determined by appropriately adjusting the three factors of acceleration voltage, emission current, and vapor deposition rate. However, the acceleration voltage is set higher than at least 4 kV. By setting the acceleration voltage in this way, the deposition rate can be set high, and the time required for deposition can be shortened. Furthermore, when the acceleration voltage is 4 kV or less, the control of the electron beam becomes unstable and the deposition rate fluctuates greatly, and it may be difficult to form a uniform film thickness, but the acceleration voltage is set to a value higher than 4 kV. By setting, the thickness of the film to be formed can be made uniform. By increasing the acceleration voltage, damage factors such as X-rays increase, and from the standpoint of reducing damage, it is normal that such conditions may be considered to be counter-effects. As long as the condition of the above formula (1) is not satisfied, the damage to the previously formed layer can be reduced even if the acceleration voltage is higher than 4 kV. This is because when the film is formed by vapor deposition, the film formed at the initial stage of the film formation functions as a protective film that alleviates damage to the previously formed layer. However, if the vapor deposition rate is set high, the protective film can be used. Since it is formed as quickly as possible, it is presumed that damage to the previously formed layer can be reduced. In addition, by setting the deposition rate high, even if the amount of energy given to the previously formed layer increases per unit time, the time required for deposition is shortened, so it is formed first when depositing. It is presumed that the total amount of energy applied to the layer is suppressed, and damage to the previously formed layer can be reduced.

  The three elements of acceleration voltage, emission current, and deposition rate can be easily set to desired values in a normal electron beam deposition apparatus. Although it depends on the type of the electron beam vapor deposition apparatus, the vapor deposition rate is first set to a desired value, and the acceleration voltage and the emission current are adjusted so as to meet this value, so that the setting satisfying the formula (1) can be easily adjusted. . The three elements of the acceleration voltage, the emission current, and the vapor deposition rate are related to each other. Therefore, the vapor deposition rate is naturally adjusted to a high value as long as the equations (1) and (2) are satisfied.

  As another preferred embodiment of the production method of the present invention, electron beam vapor deposition is further performed so as to satisfy the following formula (3).

  Emission current> 100 (mA) (3)

  As long as the above formula (1) is satisfied, by setting the emission current to be greater than 100 mA, damage to the previously formed layer can be suppressed while increasing the deposition rate. The emission current is adjusted to at least larger than 100 mA, preferably 300 mA or more, more preferably 400 mA or more.

  Further, as another preferred embodiment of the production method of the present invention, electron beam evaporation is performed so as to satisfy the following formula (4).

  Deposition rate ≧ 1 (nm / sec) (formula 4)

  The deposition rate is a value obtained by dividing the thickness of the layer formed by electron beam deposition by the time required from the start of deposition to the end of deposition. When the electron beam evaporation method is applied to the manufacture of an organic EL element, the evaporation rate is usually set from 0.1 nm / sec to 0.3 nm / sec for reasons such as avoiding the influence of the above damage factors. Many. However, in the production method of the present invention, the deposition rate can be set higher than usual as long as the condition of the above formula (1) is satisfied. By increasing the deposition rate, the deposition process can be completed in a shorter time.

  As described above, at least one of the first electrode portion and the second electrode portion, which are stacked after the organic light emitting layer is formed, is formed by the electron beam evaporation method under the predetermined conditions. The In the manufacture of the organic EL element, the layers constituting the electrodes are laminated on the organic light emitting layer even after the organic light emitting layer is formed. At this time, if the organic light emitting layer is damaged by electron beam evaporation, the PL intensity of the organic EL element is likely to be lowered. However, according to the manufacturing method of the present invention, it is difficult to damage the organic light emitting layer even when further layers are formed on the organic light emitting layer by the electron beam evaporation method. can do. In addition, suppression of damage to the organic light emitting layer can result in prevention of a decrease in EL light emission efficiency (ratio of light emission luminance to applied voltage). As described above, since the manufacturing method of the present invention can suppress damage due to electron beam evaporation, the yield of products can be improved.

  The manufacturing method of the present invention can be applied to the case where a layer constituting an organic EL element is formed by an electron beam evaporation method. Since organic EL elements often use various inorganic materials as electrode materials, the production method of the present invention can be suitably used when the electrodes are formed by electron beam evaporation. Examples of inorganic materials that can be suitably used include Al, Zn, In, Ga, Sn, Ni, Cr, Mn, Ti, Mo, Ta, W, Ag, Au, oxides thereof, nitrides thereof, and alkalis. 1 type, or 2 or more types of composite materials chosen from the group which consists of an earth metal, an alkaline earth metal oxide, an alkaline earth metal fluoride, an alkali metal oxide, and an alkali metal fluoride are mentioned. .

  Moreover, since the manufacturing method of this invention can reduce the damage by electron beam evaporation even when an organic light emitting layer is formed with a high molecular compound, it is suitable as a manufacturing method of such an organic EL element.

2. Next, an embodiment of an organic EL element that can be manufactured by the manufacturing method of the present invention will be described in more detail. In addition, the manufacturing method of this invention is not necessarily limited to the following organic EL element.

2.1. Laminated structure of organic EL element of this embodiment An organic EL element of this embodiment includes a first electrode part including an anode, a second electrode part including a cathode, and the first and second electrode parts. And an organic light emitting layer disposed. The first electrode portion includes a metal-doped molybdenum oxide layer so as to be located between the anode and the organic light emitting layer. Each of the first electrode portion and the second electrode portion may be provided with layers having other functions.

  Examples of the layer provided between the cathode and the organic light emitting layer in the second electrode portion include an electron injection layer, an electron transport layer, and a hole blocking layer. When both the electron injection layer and the electron transport layer are provided between the cathode and the organic light emitting layer, a layer in contact with the cathode is referred to as an electron injection layer, and a layer excluding this electron injection layer is referred to as an electron transport layer.

  The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode. The electron transport layer is a layer having a function of improving electron injection from the cathode, the electron injection layer, or the electron transport layer closer to the cathode. The hole blocking layer is a layer having a function of blocking hole transport. In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.

  The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

  Examples of the layer provided between the anode and the organic light emitting layer include a hole injection layer, a hole transport layer, and an electron block layer. When only one layer is provided between the anode and the organic light emitting layer, the layer is referred to as a hole injection layer. When both the hole injection layer and the hole transport layer are provided between the anode and the organic light emitting layer, the layer in contact with the anode is called the hole injection layer, and the layers excluding this hole injection layer are It is called a hole transport layer.

  The hole injection layer is a layer having a function of improving hole injection efficiency from the anode. The hole transport layer is a layer having a function of improving hole injection from the anode, the hole injection layer, or the hole transport layer closer to the anode. The electron blocking layer is a layer having a function of blocking electron transport. In the case where the hole injection layer and / or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer.

  The fact that the electron blocking layer has a function of blocking electron transport makes it possible, for example, to produce an element that allows only electron current to flow and confirm the blocking effect by reducing the current value.

  The electron injection layer and the hole injection layer may be collectively referred to as a charge injection layer, and the electron transport layer and the hole transport layer may be collectively referred to as a charge transport layer.

An example of a layer structure that can be taken by the organic EL element of the present embodiment is shown below.
a) Anode / hole injection layer / organic light emitting layer / cathode b) Anode / hole injection layer / organic light emitting layer / electron injection layer / cathode c) Anode / hole injection layer / organic light emitting layer / electron transport layer / cathode d) Anode / hole injection layer / organic light emitting layer / electron transport layer / electron injection layer / cathode e) Anode / hole injection layer / hole transport layer / organic light emitting layer / cathode f) Anode / hole injection layer / Hole transport layer / organic light emitting layer / electron injection layer / cathode g) anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode h) anode / organic light emitting layer / electron Injection layer / cathode
i) Anode / organic light emitting layer / electron transport layer / electron injection layer / cathode (Here, the symbol “/” indicates that the layers sandwiching the symbol “/” are laminated adjacently. The same shall apply hereinafter.)

The organic EL device of the present embodiment may have two or more organic light emitting layers, and examples of the organic EL device having two organic light emitting layers include the layer configuration shown in j) below. Can do.
j) Anode / charge injection layer / hole transport layer / organic light emitting layer / electron transport layer / charge injection layer / charge generation layer / charge injection layer / hole transport layer / organic light emitting layer / electron transport layer / charge injection layer / cathode

As an organic EL device having three or more organic light emitting layers, specifically, (charge generation layer / charge injection layer / hole transport layer / organic light emission layer / electron transport layer / charge injection layer) is one. Examples of the repeating unit include a layer structure including two or more repeating units shown in the following k).
k) Anode / charge injection layer / hole transport layer / organic light emitting layer / electron transport layer / charge injection layer / (the repeating unit) / (the repeating unit) /.../ cathode

  In the layer configurations j) and k), each layer other than the anode, the cathode, and the organic light emitting layer can be deleted as necessary.

  Here, the charge generation layer is a layer that generates holes and electrons by applying an electric field. Examples of the charge generation layer include a thin film made of vanadium oxide, indium tin oxide (abbreviated as ITO), molybdenum oxide, or the like.

  The organic EL element can be mounted on the main surface of the substrate and is preferably covered with a sealing member such as a sealing film or a sealing plate for sealing. When the organic EL element is provided on the main surface of the substrate, in many cases, an anode is disposed on the substrate side, but a cathode may be disposed on the substrate side.

  In the organic EL element, an insulating layer having a film thickness of 2 nm or less may be provided adjacent to the electrode in order to improve adhesion to the electrode or charge injection from the electrode. In addition, a thin buffer layer may be inserted between each of the aforementioned layers in order to improve adhesion at the interface or prevent mixing.

  In order to emit light from the organic light emitting layer, the organic EL element normally allows light to pass through any one of the organic light emitting layers. Specifically, for example, in the case of an organic EL device having a configuration of anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode / sealing member, anode, hole injection All of the layer and the hole transport layer are capable of transmitting light, so that it is a so-called bottom emission type device, or all of the electron transport layer, electron injection layer, cathode and sealing member can transmit light Thus, a so-called top emission type element can be obtained. In the case of an organic EL device having the structure of cathode / electron injection layer / electron transport layer / organic light emitting layer / hole transport layer / hole injection layer / anode / sealing member, the cathode, electron injection layer and electron transport layer All of the light-transmitting element is a so-called bottom emission type element, or all of the hole transport layer, the hole injection layer, the anode and the sealing member are light-transmitting, so-called top It can be an emission type element. In this case, it is preferable that the visible light transmittance from the organic light emitting layer to the light emitting layer is 30% or more as a material that can transmit light. In the case of an element that requires light emission in the ultraviolet region or infrared region, a device having a transmittance of 30% or more in the region is preferable.

  The order and number of layers to be laminated, and the thickness of each layer can be appropriately used in consideration of light emission efficiency and element lifetime.

2.2. One embodiment of organic EL element (FIG. 1)
One embodiment of the organic EL element is shown in FIG. In the embodiment shown in FIG. 1, the first electrode portion 20 is provided on the support substrate 10, the organic light emitting layer 30 is laminated thereon, and the second electrode portion 40 is laminated thereon. In the embodiment of FIG. 1, the first electrode portion 20 has a three-layer structure in which an anode 21, a hole injection layer 22, and a hole transport layer 23 are stacked in order from the support substrate 10 side. The second electrode unit 40 has a three-layer structure in which an electron transport layer 43, an electron injection layer 42, and a cathode 41 are stacked in this order from the organic light emitting layer 30 side.

  In the embodiment shown in FIG. 1, the hole injection layer 22 is a metal-doped molybdenum oxide layer. In the embodiment shown in FIG. 1, at least one of the electron transport layer 43, the electron injection layer 42, and the cathode 41 provided in the upper layer of the organic light emitting layer 30 is 1.5. As described above, it is formed by electron beam evaporation under predetermined conditions.

Since the metal doped molybdenum oxide layer as the hole injection layer 22 is resistant to the wet process, the hole transport layer 23, the organic light emitting layer 30, the electron transport layer 43, which are higher than the metal doped molybdenum oxide layer, Even when the electron injection layer 42 and the cathode 41 are formed by a wet process, they are not easily damaged. Moreover, when using the material with low resistance to a wet process for the anode 20, it can protect from receiving a damage in the middle of the manufacturing process of an organic EL element.
Further, when the organic light emitting layer 30 is provided and then one layer of the electron transport layer 43, the electron injection layer 42, and the cathode 41 to be laminated is provided, the above 1.5. By adopting the electron beam evaporation method, damage to the organic light emitting layer 30 when the layer is formed can be suppressed even by the evaporation method.

  As another modification, another layer may be interposed between the anode 20 and the metal-doped molybdenum oxide layer as the hole injection layer 22, and in this case, the metal doping is performed so as to cover the other layer. A molybdenum oxide layer is formed. As another modified example, a mode in which the electron transport layer 43 is not formed but the electron injection layer 42 is directly provided on the organic light emitting layer 30 can be cited. Since there are many inorganic materials suitable for forming the electron injection layer, when the electron injection layer 42 is provided on the organic light emitting layer 30 using an inorganic material, the above 1.5. It is preferable to employ the electron beam evaporation method described in the above.

  Furthermore, as another modification, the second electrode portion may be provided on the support substrate, and the first electrode portion may be provided in the upper layer of the organic light emitting layer. Further, as another modification, an organic EL element of any type of a bottom emission type that takes light from the support substrate side, a top emission type that takes light from the side opposite to the support substrate, or a double-sided daylight type may be used. As yet another modification, a layer having other functions such as an arbitrary protective film, buffer film, and reflective layer may be provided. The organic EL element is further covered with a sealing substrate to form an organic EL device in which the organic EL element is shielded from the outside air.

3. Organic EL Device The organic EL device of the present invention is a device on which the organic EL element of the present invention is mounted, specifically a light source device, a display device, and a lighting device. As described above, the organic EL device manufactured by the manufacturing method of the present invention can suppress damage given to the organic layer and can be an element excellent in light emission luminance and product life. Therefore, the organic EL element manufactured by the manufacturing method of the present invention is preferably used as a planar light source device, a segment display device, a dot matrix display device, a backlight of a liquid crystal display device, an illumination device, and the like on which the device is mounted. it can.

  In order to obtain planar light emission using the organic EL device of the present invention, the planar anode and cathode may be arranged so as to overlap each other. In addition, in order to obtain pattern-like light emission, a method of installing a mask provided with a pattern-like window on the surface of the planar light-emitting element, an organic material layer of a non-light-emitting portion is formed extremely thick and substantially non- There are a method of emitting light and a method of forming either one of the anode or the cathode or both electrodes in a pattern. By forming a pattern by any of these methods and arranging several electrodes so that they can be turned on and off independently, a segment type display device capable of displaying numbers, letters, simple symbols, and the like can be obtained. Furthermore, in order to obtain a dot matrix element, a passive matrix substrate in which anodes and cathodes are both formed in stripes and arranged so as to be orthogonal to each other, or an active matrix substrate in which thin film transistors are arranged and controlled in units of pixels is used. That's fine. Furthermore, partial color display and multi-color display can be performed by separately applying light emitting materials having different emission colors or using a color filter or a fluorescence conversion filter. These display elements can be used as display devices for computers, televisions, mobile terminals, mobile phones, car navigation systems, video camera viewfinders, and the like.

  Furthermore, the planar light-emitting device is self-luminous and thin, and can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source or display device.

  Hereinafter, the present invention will be described in more detail while showing fabrication examples, comparative examples, and verification tests thereof based on the actual fabrication process of an organic EL element, but the present invention is not limited to the following fabrication examples. Absent.

<Production Example 1>
(1) Element preparation An ITO thin film having a film thickness of about 150 nm is formed by a sputtering method, and this ITO thin film is patterned into a predetermined shape, and a glass substrate on which ITO corresponding to an anode is formed is subjected to UV-O ₃ treatment. For 10 minutes. Next, a polymer light-emitting organic material (product name: BP361, manufactured by Summation Co., Ltd.) dissolved in xylene on a glass substrate patterned with ITO at a rotational speed of 1600 revolutions by spin coating is used. It was rotated for 30 seconds to form a film (film thickness 70 nm). Next, the substrate was introduced into the vacuum chamber and transferred to the heating chamber. Next, nitrogen was introduced into the heating chamber and heated at a substrate temperature of about 130 ° C. for 40 minutes under atmospheric pressure and inert gas. After that, the substrate is moved to the deposition chamber, the cathode mask is aligned with the substrate, and the electrode is deposited while rotating the mask and the substrate while maintaining the relative position of the two, and an element for damage evaluation Was made. The element structure was glass substrate / ITO / layer made of polymer light emitting organic material / Al.

The degree of vacuum in the chamber before vapor deposition was 3 × 10 ⁻⁵ Pa or less. Tokki Co., Ltd. Small-ELVESS is used for the main vapor deposition and heating system, and the device is in a vacuum or nitrogen atmosphere during the process, and the device is not exposed to the atmosphere.

  The electrode was deposited by an electron beam deposition method using an electron gun (model number: electron gun EBG-203UB4H, power supply JST-10F, manufactured by JEOL Ltd.). Moreover, Al was used as an electrode material. Electron beam deposition was performed by setting the operating conditions of the deposition apparatus to an acceleration voltage of 10 kV, Al at a deposition rate of 1 nm / sec, and a film thickness of 100 nm. The emission current was adjusted to 460 mA through adjustment of acceleration voltage and deposition rate. The film formation electric energy value under this setting condition was 4600 W · sec / nm.

(2) Evaluation The organic EL device produced as described above is irradiated with excitation light having a peak wavelength of 375 nm from the glass substrate side, and the fluorescence spectrum (PL) of the polymer organic light emitting material emitted from the glass substrate side is measured. did. The measurement wavelength region was 380 to 780 nm. The measured PL spectrum showed blue emission with a peak wavelength of 465 nm. Next, PL intensities were added at intervals of 5 nm in the wavelength region of 405 to 665 nm, and the PL integrated intensity emitted to the front from the layer made of the polymer organic light emitting material was estimated. The value was about 0.0446 W / (m ² · sr (steradian)). In addition, the measurement apparatus used OLED TEST SYSTEM by Tokyo System Development Co., Ltd.

  Next, the relative PL integrated intensity ratio of the element of Preparation Example 1 was expressed as a percentage based on the PL integrated intensity evaluated for the organic EL element manufactured according to Reference Example 1 below. The relative PL integral intensity ratio is a value obtained by dividing the PL integral intensity of the target organic EL element by the PL integral intensity of the organic EL element of Reference Example 1 and further multiplying by 100. As a result, the relative PL integral intensity ratio of the organic EL element of Production Example 1 was about 99.0%, and no decrease in PL integral intensity was observed, confirming that the polymer organic light-emitting material was not damaged. . In addition, since the following reference example 1 was produced by the resistance heating method, it is considered that the damage given to the polymer organic light emitting material is very small.

<Production Example 2>
(1) Element preparation Al was vapor-deposited as an electrode by the electron beam vapor deposition method under the setting conditions of an acceleration voltage of 10 kV, a vapor deposition rate of 0.5 nm / sec, a film thickness of 100 nm, and an emission current of 420 mA. The deposition power amount value under this setting condition is 8400 W · sec / nm. Except for these points, an element for damage evaluation was produced in the same manner as in Production Example 1.

(2) Evaluation When the relative PL integrated intensity ratio (percentage) of Production Example 2 was determined in the same manner as in Production Example 1, it was 95.4%. The PL integrated intensity was about 0.0431 W / (m ² · sr).

<Production Example 3>
(1) Element preparation Al was vapor-deposited as an electrode by the electron beam vapor deposition method under the setting conditions of an acceleration voltage of 10 kV, a vapor deposition rate of 0.2 nm / sec, a film thickness of 100 nm, and an emission current of 370 mA. The deposition power amount value under this setting condition is 18500 W · sec / nm. Except for these points, an element for damage evaluation was produced in the same manner as in Production Example 1.

(2) Evaluation When the relative PL integral intensity ratio (percentage) of the element of Preparation Example 3 was determined in the same manner as in Preparation Example 1, it was 92.8%. The PL integrated intensity was about 0.0408 W / (m ² · sr).

<Comparative Example 1>
-Element preparation Al was vapor-deposited as an electrode by the electron beam vapor deposition method under the setting conditions of an acceleration voltage of 10 kV, a vapor deposition rate of about 0.1 nm / sec, an emission current: 340 mA, and a film thickness of 100 nm. The deposition power amount value under this setting condition is 34000 W · sec / nm. Except for these points, a device for damage evaluation was produced in the same manner as in Production Example 1.

(2) Evaluation In the same manner as in the evaluation of Production Example 1, the PL integrated intensity was estimated. The value was about 0.0342 W / (m ² · sr). When the relative PL integrated intensity ratio (percentage) of the device of Comparative Example 1 was determined in the same manner as in Production Example 1, it was 76.7%. From this, it was found that the PL integrated intensity decreased and the polymer organic light emitting material was damaged.

<Reference Example 1>
(1) Device preparation The resistance heating method was used for electrode vapor deposition. A tungsten boat was used as the vapor deposition boat and a current of about 80 A was applied to heat and deposit the Al on the boat. The Al film thickness was 100 nm. The deposition rate of Al was 0.1 nm / sec until the Al deposition film thickness was 10 nm, 0.2 nm / sec until 30 nm, and 0.4 nm / sec until 100 nm. The vapor deposition machine uses try-ELVESS made by Tokki. A device was manufactured in the same manner as in Manufacturing Example 1 except for the above.

(2) Evaluation The PL integrated intensity was estimated in the same manner as in the evaluation in Production Example 1. The value was about 0.045 W / (m ² · sr). According to the vapor deposition method of Reference Example 1, it is estimated that damage that may occur in the case of the electron beam vapor deposition method does not occur. When the relative PL integral intensity ratio is expressed, the value in Reference Example 1 is 0.045 W / (m ² · sr) was 100%.

  Next, as Production Example 4 and Production Example 5, elements having a different element configuration from those of Production Examples 1 to 3 were produced. The specific layer structure of the fabricated device is “glass substrate / ITO film / hole injection layer / electron blocking layer / light emitting layer / Ba layer / Al layer / sealing glass”.

<Synthesis Example of Polymer Compound 1>
The polymer compound 1 to be the electron blocking layer was synthesized. First, 2,7-bis (1,3,2-dioxaborolan-2-yl) -9,9- was added to a separable flask equipped with a stirring blade, a baffle, a length-adjustable nitrogen introduction tube, a cooling tube, and a thermometer. 158.29 parts by weight of dioctylfluorene, 136.11 parts by weight of bis- (4-bromophenyl) -4- (1-methylpropyl) -benzenamine, tricaprylmethylammonium chloride (product name: Aliquat, manufactured by Henkel) 336) 27 parts by weight and 1800 parts by weight of toluene were charged, and the temperature was increased to 90 ° C. with stirring while introducing nitrogen from the nitrogen introduction tube. After adding 0.066 parts by weight of palladium (II) acetate and 0.45 parts by weight of tri (o-toluyl) phosphine, 573 parts by weight of a 17.5% aqueous sodium carbonate solution was added dropwise over 1 hour. After completion of the dropwise addition, the nitrogen inlet tube was lifted from the liquid surface and kept under reflux for 7 hours, then 3.6 parts by weight of phenylboric acid was added, kept under reflux for 14 hours, and cooled to room temperature. After removing the reaction solution aqueous layer, the reaction solution oil layer was diluted with toluene and washed with 3% acetic acid aqueous solution and ion-exchanged water. 13 parts by weight of sodium N, N-diethyldithiocarbamate trihydrate was added to the separated oil layer, stirred for 4 hours, then passed through a mixed column of activated alumina and silica gel, and toluene was passed through to wash the column. did. The filtrate and washings were mixed and then added dropwise to methanol to precipitate the polymer. The obtained polymer precipitate was separated by filtration, washed with methanol, and then dried with a vacuum dryer to obtain 192 parts by weight of polymer. The resulting polymer is referred to as polymer compound 1. The polymer compound 1 had a polystyrene equivalent weight average molecular weight of 3.7 × 10 ⁵ and a number average molecular weight of 8.9 × 10 ⁴ .

(GPC analysis method)
The polystyrene equivalent weight average molecular weight and number average molecular weight were determined by gel permeation chromatography (GPC). Standard polystyrene made by Polymer Laboratories was used to prepare a GPC calibration curve. The polymer to be measured was dissolved in tetrahydrofuran to a concentration of about 0.02% by weight, and 10 μL was injected into GPC.

  Shimadzu LC-10ADvp was used for the GPC apparatus. As the column, two PLgel 10 μm MIXED-B columns (300 × 7.5 mm) manufactured by Polymer Laboratories Inc. were used in series, and tetrahydrofuran was flowed at 25 ° C. and a flow rate of 1.0 mL / min as a mobile phase. A UV detector was used as a detector, and absorbance at 228 nm was measured.

<Production Example 4>
(Production of organic EL element)
A hole injection layer was formed on the ITO thin film using a glass substrate on which an ITO thin film was patterned on the surface and an electrode made of the ITO thin film was formed. Specifically, a suspension of poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (HC Starck B-Tech, Bytron P TP AI 4083) was filtered through a 0.5 micron filter, and this suspension was suspended. The turbid liquid was formed into a film with a thickness of 65 nm by spin coating from the side of the substrate on which the ITO was formed to form a hole injection layer. Further, the hole injection layer formed in areas where application was unnecessary, such as the extraction electrode part and the sealing area, was removed, and the film was dried on the hot plate at 200 ° C. for 10 minutes in the air.

  Next, the polymer compound 1 described above was formed by spin coating on the substrate on which the hole injection layer was formed, and an electron blocking layer having a thickness of 20 nm was formed. Further, the electron block layer formed in the unnecessary region such as the extraction electrode portion and the sealing area is removed, and the hot block is used at 180 ° C. for 60 minutes in a glove box substituted with high-purity nitrogen. Baking was performed.

Next, a polymer light-emitting organic material (BP361 made by Summation Co., Ltd.) was formed on the electron block layer by a spin coating method to form a light-emitting layer having a thickness of 60 nm. Furthermore, the light emitting layer formed in the unnecessary area | region of application | coating, such as an extraction electrode part and a sealing area, was removed.
The subsequent processes up to the sealing were performed in vacuum or nitrogen so that the element was not exposed to the atmosphere during the process.

  Next, the substrate was heated in nitrogen at a temperature of about 100 ° C. for 60 minutes in a heating chamber of a vacuum evaporation machine (Small-ELVESS) manufactured by Tokki Corporation. Thereafter, the substrate was moved to the vapor deposition chamber, and the cathode mask was aligned so as to face the light emitting layer so that the second electrode portion was formed on the light emitting portion and on the extraction electrode portion. Further, the second electrode portion was formed by vapor deposition while rotating the mask and the substrate.

  The second electrode portion has a two-layer structure of a Ba layer and an Al layer. First, Ba is heated by a resistance heating method, vapor deposition is performed at a deposition rate of about 0.1 nm / sec, and a film thickness is 5 nm, and then an acceleration voltage of 10 kV, a deposition rate of 1 nm / sec, and an emission by an electron beam deposition method. Al was vapor-deposited as an electrode (cathode) under the setting conditions of current: 460 mA and film thickness of 100 nm. The deposition power amount value under this setting condition is 4600 W · sec / nm.

  Next, the sealing glass with the UV curable resin applied to the periphery was bonded to the substrate under reduced pressure, and then returned to atmospheric pressure. Further, the sealing glass was fixed to the substrate by irradiating UV, and an organic EL device having a light emitting region of 2 × 2 mm was produced. The obtained organic EL device had a layer structure of glass substrate / ITO film / hole injection layer / electron blocking layer / light emitting layer / Ba layer / Al layer / sealing glass.

(Evaluation of organic EL elements)
When a voltage was applied to the produced organic EL element and current-voltage-luminance characteristics were measured, when the applied voltage was 6.83 V, the current density was 1.7 × 10 ⁻² A / cm ² and the front luminance was 1000 cd. / M ² . The maximum power efficiency was 3.02 (lm / W). Further, the PL integrated intensity was measured in the same manner as in Production Example 1. The PL integrated intensity was 0.0238 W / (m ² · sr). The organic EL element of Production Example 4 and the damage evaluation element of Production Example 1 have different layer configurations, but the formation conditions of the electrode made of Al in Production Example 4 are made of Al in Production Example 1 described above. Since the electrode formation conditions are the same, the damage to the light-emitting layer when forming the electrode of Preparation Example 4 is assumed to be the same as that of Preparation Example 1, and relative to the organic EL element manufactured in Preparation Example 4. The PL integrated intensity ratio was set to 99%, which is the same as the relative PL integrated intensity ratio of Production Example 1, and the relative PL integrated intensity ratio of the organic EL element of Production Example 5 described later was estimated. That is, the reference PL integral intensity is calculated so that the relative PL integral intensity ratio of the organic EL element produced in this production example 4 is 99%, and the production example described later is used using the calculated PL integral intensity. The relative PL integral intensity ratio of 5 organic EL elements was calculated.

<Production Example 5>
(Production of organic EL element)
An organic EL element was produced in the same manner as in Production Example 4. However, as the second electrode portion, Ba is first heated using a resistance heating method, evaporated at a deposition rate of about 0.1 nm / sec and a film thickness of 5 nm, and then an acceleration voltage of 10 kV is formed thereon by an electron beam evaporation method. Then, Al was vapor-deposited as an electrode (cathode) under the setting conditions of vapor deposition rate 2 nm / sec, emission current: 570 mA, and film thickness 100 nm. The deposition power amount value under this setting condition is 2850 W · sec / nm.

(Evaluation of organic EL elements)
A voltage was applied to the organic EL element produced in the same manner as in Production Example 4, and current-voltage-luminance characteristics were measured. When the applied voltage was 6.51 V, the current density was 1.8 × 10 ⁻² A / cm ² and the front luminance was 1000 cd / m ² . The maximum power efficiency was 3.06 (lm / W). Further, the PL integrated intensity was measured in the same manner as in Production Example 1. The PL integrated intensity was 0.0235 W / (m ² · sr), and the relative PL integrated intensity ratio was 96.1%.

  FIG. 2 is a diagram showing the relative PL integral intensity ratio of the devices fabricated in fabrication examples 1 to 5 and comparative example 1. The horizontal axis represents the deposition power amount value, and the vertical axis represents the relative PL integrated intensity ratio. As shown in FIG. 2, when the deposition power amount value was less than 20000, the relative PL integral intensity ratio was about 90% or more, and it was confirmed that damage to the element when forming the cathode could be suppressed.

<Production Example 6>
(6-1: Deposition of Al-doped MoO ₃ on a glass substrate by a vacuum deposition method)
A plurality of glass substrates were prepared, one side of which was partially covered with a vapor deposition mask, and attached to the vapor deposition chamber using a substrate holder.

MoO ₃ powder (manufactured by Aldrich, purity 99.99%) was packed in a tungsten board for a box-type sublimation substance, covered with a cover with holes so that the material would not scatter, and set in a vapor deposition chamber. Al (manufactured by Koyo Chemical Co., Ltd., purity 99.999%) was put in a crucible and set in a vapor deposition chamber.

The degree of vacuum in the vapor deposition chamber is set to 3 × 10 ⁻⁵ Pa or less, MoO ₃ is gradually heated by a resistance heating method and sufficiently degassed, and Al is dissolved in a crucible by an electron beam and sufficiently degassed. After performing, it used for vapor deposition. The degree of vacuum during vapor deposition was 9 × 10 ⁻⁵ Pa or less. The film thickness and the deposition rate were constantly monitored with a crystal resonator. When the deposition rate of MoO ₃ reached about 2.8 約 / sec and the deposition rate of Al reached about 0.1 Å / sec, the main shutter was opened and film formation on the substrate was started. During deposition, the substrate was rotated so that the film thickness was uniform. Film formation was carried out for about 36 seconds while controlling the vapor deposition rate to the above speed, and a substrate provided with a co-deposited film having a film thickness of about 100 mm was obtained. The composition ratio of Al to the total of MoO ₃ and Al in the film was about 3.5 mol%.

(6-2: Durability test)
After film formation, the obtained substrate was taken out into the atmosphere and the film surface was observed with an optical microscope (500 times). As a result, it was confirmed that the crystal structure was not observed and the film was in an amorphous state.

  When the obtained substrate was exposed to pure water for 1 minute and observed again with an optical microscope, there was no change and the surface was not dissolved. In either case, the substrate was further exposed to pure water for 3 minutes, or the film was wiped with a non-woven fabric (trade name “Bencot”, manufactured by Ozu Sangyo Co., Ltd.) containing pure water and then visually observed. The membrane remained unchanged.

  When another substrate obtained was exposed to acetone for 1 minute and observed with an optical microscope, there was no change and the surface was not dissolved. The substrate was further exposed to acetone for 3 minutes, or the film was wiped with a non-woven fabric containing acetone and visually confirmed. In either case, the film remained unchanged.

(6-3: Measurement of transmittance)
Moreover, the transmittance | permeability of the vapor deposition film after film-forming was measured using the transmittance | permeability / reflectance measuring apparatus FilmTek 3000 (A brand name, Scientific Computing International company make). The results are shown in Table 1. The transmission spectrum rose from a wavelength of about 300 nm. The transmittance at a wavelength of 320 nm was 21.6%, and the transmittance at 360 nm was 56.6%. Compared to Comparative Example 1 described later, the transmittance was 3.6 times at 320 nm and 1.6 times at 360 nm.

<Production Example 7>
A substrate provided with a co-deposited film was obtained in the same manner as in (6-1) of Preparation Example 6 except that oxygen was introduced into the chamber during the deposition. The amount of oxygen was controlled to 15 sccm by a mass flow controller. The degree of vacuum during vapor deposition was about 2.3 × 10 ⁻³ Pa. The thickness of the obtained co-deposited film was about 100 mm, and the composition ratio of Al to the total of MoO ₃ and Al in the film was about 3.5 mol%.

  After film formation, the durability of the obtained substrate was evaluated in the same manner as in Preparation Example 6 (6-2). No change was observed when exposed to either pure water or acetone.

<Production Example 8>
The vapor deposition rate was controlled in the same manner as in (6-1) of Production Example 6 except that the deposition rate was controlled to about 3.7 Å / sec for MoO _{3 and} about 0.01 Å / sec for Al, and a co-deposition film was provided. Obtained substrate. The thickness of the obtained co-deposited film was about 100 mm, and the composition ratio of Al to the total of MoO ₃ and Al in the film was about 1.3 mol%.

  After film formation, the durability of the obtained substrate was evaluated in the same manner as in Preparation Example 6 (6-2). No change was observed when exposed to either pure water or acetone.

<Production Example 9>
The substrate obtained in Preparation Example 6 (6-1) was placed in a clean oven in an air atmosphere and heat-treated at 250 ° C. for 60 minutes. After cooling, the transmittance of the deposited film was measured in the same manner as in Preparation Example 6 (6-3). The results are shown in Table 1. The transmittance at a wavelength of 320 nm was 28.9%, and the transmittance at 360 nm was 76.2%. Compared to Comparative Example 1 described later, the transmittance was 4.7 times at 320 nm and 2.2 times at 360 nm.

<Comparative example 2>
A substrate provided with a deposited film having a thickness of about 100 mm was obtained in the same manner as in Production Example 6 except that Al was not deposited and only MoO ₃ was deposited at a rate of about 2.8 mm / sec.
After film formation, the obtained substrate was taken out into the atmosphere and the film surface was observed with an optical microscope (500 times). As a result, it was confirmed that the crystal structure was not observed and the film was in an amorphous state.

  When the obtained substrate was exposed to pure water for 1 minute and observed again with an optical microscope, it was observed that a bleeding pattern was observed and the surface was melted. The substrate was further exposed to pure water for 3 minutes, or the film was wiped with a non-woven fabric soaked with pure water and visually observed. In all cases, the film disappeared.

  Another obtained substrate was exposed to acetone for 1 minute and observed with an optical microscope. As a result, a bleeding pattern was observed and the surface was melted. The substrate was further exposed to acetone for 3 minutes, or the film was wiped with a non-woven fabric containing acetone and then visually confirmed. In all cases, the film was lost.

  Further, the transmittance of the deposited film after film formation was measured in the same manner as in Preparation Example 6 (6-3). The results are shown in Table 1. The transmittance at a wavelength of 320 nm was 6.1%, the transmittance at 360 nm was 35.4%, and it was confirmed that the transmittance was low.

<Production Example 10>
(Production of organic EL element)
A glass substrate having an ITO thin film patterned on the surface was used as a substrate, and an Al-doped MoO ₃ layer having a thickness of 100 mm was deposited on the ITO thin film by a vacuum deposition method in the same manner as in Production Example 6.

  After the film formation, the substrate was taken out into the atmosphere, and the polymer compound 1 was formed on the vapor-deposited film by spin coating to form an interlayer layer having a thickness of 20 nm. The interlayer layer formed on the extraction electrode part and the sealing area was removed, and baking was performed at 200 ° C. for 20 minutes on a hot plate.

  Thereafter, a polymer light-emitting organic material (manufactured by RP158 Summation Co., Ltd.) was formed on the interlayer layer by a spin coating method to form a light-emitting layer having a thickness of 90 nm. The light emitting layer formed on the extraction electrode portion and the sealing area was removed.

  The subsequent processes up to the sealing were performed in vacuum or nitrogen so that the elements in the process were not exposed to the atmosphere.

  The substrate was heated at a substrate temperature of about 100 ° C. for 60 minutes in a vacuum heating chamber. Thereafter, the substrate was transferred to a vapor deposition chamber, and a cathode mask was aligned on the surface of the light emitting layer so that a cathode was formed on the light emitting portion and the extraction electrode portion. Further, the cathode was deposited while rotating the mask and the substrate. As a cathode, metal Ba is heated by a resistance heating method and evaporated at a deposition rate of about 2 mm / second and a film thickness of 50 mm, and Al is deposited thereon by an electron beam deposition method at an evaporation rate of about 2 mm / second and a film thickness of 150 nm. Vapor deposition.

Thereafter, the substrate is bonded to a prepared sealing glass coated with UV curable resin around the substrate, kept in vacuum, then returned to atmospheric pressure, fixed by irradiation with UV, and light emitting region Produced a 2 × 2 mm organic EL device. The obtained organic EL device had a layer structure of glass substrate / ITO film / Al-doped MoO ₃ layer / interlayer layer / light emitting layer / Ba layer / Al layer / sealing glass.

(Evaluation of organic EL elements)
The manufactured element was energized so that the luminance was 1000 cd / m ^2, and current-voltage characteristics were measured. In addition, the device was driven at a constant current at 10 mA, light emission was started at an initial luminance of about 2000 cd / m ² , the light emission was continued as it was, and the light emission lifetime was measured. The results are shown in Tables 2 and 3. Compared to Comparative Example 3 described later, the maximum power efficiency is slightly higher, the drive voltage at the time of 1000 cd / m ² emission is reduced, and the life is extended by about 1.6 times.

<Production Example 11>
The organic EL device was manufactured by operating in the same manner as in Preparation Example 10 except that the Al-doped MoO ₃ layer was formed in the same procedure as in Preparation Example 8 instead of Preparation Example 7, and the current-voltage characteristics and emission lifetime were improved. It was measured. The emission lifetime was measured by driving at a constant current of 10 mA, starting emission at an initial luminance of about 2000 cd / m ² , and then continuing emission. The results are shown in Tables 2 and 3. Compared to Comparative Example 3 to be described later, the maximum power efficiency is slightly higher, the driving voltage at the time of 1000 cd / m ² emission is lowered, and the life is extended about 2.4 times.

<Comparative Example 3>
Instead of depositing the Al-doped MoO ₃ layer, the same procedure as in Comparative Example 2 was followed except that the MoO ₃ layer was deposited to operate in the same manner as in Production Example 10 to produce an organic EL element, and the current-voltage characteristics The emission lifetime was measured. The emission lifetime was measured by driving at a constant current of 10 mA, starting emission at an initial luminance of about 2000 cd / m ² , and then continuing emission. The results are shown in Tables 2 and 3.

It is sectional drawing which shows one Embodiment of an organic EL element. It is a figure which shows the measurement result of PL intensity | strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Support substrate 20 1st electrode part 21 Anode 22 Hole injection layer (metal dope molybdenum oxide layer)
23 hole transport layer 30 organic light emitting layer 40 second electrode part 41 cathode 42 electron injection layer 43 electron transport layer

Claims (8)

A method of manufacturing an organic electroluminescence device comprising a first electrode part including an anode, a second electrode part including a cathode, and an organic light emitting layer disposed between the first and second electrode parts,
Providing the first electrode portion with a metal-doped molybdenum oxide layer disposed between the anode and the organic light emitting layer;
Of the layers constituting the first and second electrode portions, at least one layer laminated after the organic light emitting layer is formed is represented by the following formulas (1) , (2) , (3) and (4). :
Acceleration voltage x Emission current ÷ Deposition rate <20000 (W · sec / nm) (1) Acceleration voltage> 4 (kV) (2)
Emission current> 100 (mA) (3)
Deposition rate ≧ 1 (nm / sec) (formula 4)
A process of forming by electron beam vapor deposition that satisfies the condition of
The manufacturing method of an organic electroluminescent element containing this. The method for producing an organic electroluminescence device according to claim 1, wherein the dopant metal contained in the metal-doped molybdenum oxide layer is a transition metal, a Group 13 metal of the periodic table, or a mixture thereof. The layers formed by the electron beam evaporation are Al, Zn, In, Ga, Sn, Ni, Cr, Mn, Ti, Mo, Ta, W, Ag, Au, oxides thereof, nitrides thereof, alkalis It is formed of one or more materials selected from the group consisting of earth metals, alkaline earth metal oxides, alkaline earth metal fluorides, alkali metal oxides, and alkali metal fluorides. The manufacturing method of the organic electroluminescent element of Claim 1 or 2 . The manufacturing method of the organic electroluminescent element as described in any one of Claim 1 to 3 which forms the said organic light emitting layer with a polymeric organic compound. In the step of providing the metal doped molybdenum oxide layer, the anode providing a metal-doped molybdenum oxide layer in direct contact, the method of manufacturing an organic electroluminescent device according to any one of claims 1 4. After forming the metal doped molybdenum oxide layer, a layer containing an organic material, manufacturing method of the organic electroluminescent device according to any one of claims 1 to 5. In the step of providing the metal doped molybdenum oxide layer includes depositing molybdenum oxide and the dopant metal at the same time, the method of manufacturing the organic electroluminescent device according to any one of claims 1 to 6. The method of manufacturing an organic electroluminescence device according to claim 7 , further comprising a step of heating a layer formed by the step of depositing after the step of depositing molybdenum oxide and a dopant metal simultaneously.

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