JP5572081B2 - Method for manufacturing organic electroluminescent device and organic electroluminescent device - Google Patents

Description

  The present invention relates to a method for manufacturing an organic electroluminescent element and an organic electroluminescent element.

  Organic electroluminescent elements are expected as next-generation displays, lighting devices, and backlights because they can emit surface light. In order to display a light emission pattern of characters or images on a display using an organic electroluminescence device, the electrode or the organic electroluminescence device is processed into a display pattern to emit light, or the electrode is processed into a matrix and driven. A method of displaying light emission using a circuit is used. The former method and the latter method can be properly used according to the purpose of use of the organic electroluminescence device, the manufacturing cost, etc., for example, the former method can display only a specific pattern, but advanced fine processing technology associated with patterning, In addition, complicated wirings and driving circuits are unnecessary, and a luminescent advertisement, a fixed display device, and the like can be manufactured at low cost.

As a method of processing an organic electroluminescent element into a display pattern, an organic electroluminescent element is irradiated with electromagnetic waves (hereinafter also referred to as “exposure” to “light irradiation”), thereby partially driving voltage (hereinafter, “ Several methods have been proposed for increasing the light emission luminance by increasing the light emission start voltage).
For example, a method for patterning an organic electroluminescent element has been proposed in which a light-emitting layer made of a light-emitting material is irradiated with ultraviolet light and the irradiated portion is a non-light-emitting region (see Patent Document 1).
Further, in a method for producing a laminated organic electroluminescent device having at least one hole transport layer containing an arylamine and an electron transporting light emitting layer, the characteristics of the hole transport layer are changed by electromagnetic wave irradiation, and the organic electroluminescent device It has been proposed to adjust the brightness of the light emitting part partially and arbitrarily (see Patent Document 2).

  With these proposals, it is possible to manufacture an organic electroluminescent element that has high luminous efficiency, can be easily patterned, and can partially adjust the brightness of the light emitting part.

However, organic electroluminescence devices used for pattern formation are mass-produced at once, and it is assumed that patterns are exposed and used as needed. In these proposals, a hole injection layer is formed. After that, it is necessary to irradiate electromagnetic waves to form the remaining layers. Thus, in the case of irradiating each organic electroluminescent element in the course of production, there is a problem that the production efficiency is lowered.
In addition, as described above, when a pattern is formed on an organic electroluminescent device that is mass-produced at one time, it is possible to further increase the sensitivity of the organic electroluminescent device to electromagnetic waves and reduce the exposure time. However, these proposals do not describe or suggest the production of an organic electroluminescent device that facilitates pattern formation in such a case.

  Furthermore, it has been found that the material of the hole injection layer is important in the organic electroluminescence device whose driving voltage is increased by exposure, and the material having the arylamine skeleton used in the above proposal is used for the hole injection layer. When used, the driving voltage can be easily increased by electromagnetic wave irradiation, and the current flowing through the portion can be reduced. However, copper generally known as a material for a hole injection layer of an organic electroluminescence device can be used. In an organic electroluminescent device using phthalocyanine (CuPc) or iridium complex in the hole injection layer, the drive voltage hardly increases even when electromagnetic wave irradiation is performed, and it can be used as an organic electroluminescent device used for pattern formation. There was a problem that I could not.

On the other hand, in the manufacture of an organic electroluminescent element, it is common to perform oxygen plasma treatment or UV-ozone treatment as a surface treatment of electrodes (for example, ITO film) constituting the organic electroluminescent element. It is known that the driving voltage can be lowered by decomposing and cleaning the organic matter on the electrode and eliminating the barrier to the HOMO level in the organic film on the electrode. In addition, the electrode surface treatment using oxygen gas has a problem that an element having sufficient durability cannot always be obtained, and in order to solve the problem, a gas containing no oxygen such as nitrogen gas or argon gas is used. The surface treatment method used has been proposed.
For example, it has been proposed to perform surface modification by irradiating an ITO film with positive ions with an inert gas in an energy range of 20 eV to 100 eV (see Patent Document 3).
Further, in the organic electroluminescent device in which an organic light emitting layer containing an organic light emitter is provided between the anode and the cathode, the surface portion of the anode is made of nitrogen, sulfur, selenium, tellurium, phosphorus and halogen elements. It has been proposed to process the surface of the anode by converting at least one selected element into plasma (see Patent Document 4).

  However, in these proposals, as a means for solving the problem of improving the durability of the organic electroluminescence device, surface treatment is performed using a specific gas, and the anode is surface-treated using a specific gas. Thus, there is no description or suggestion that the sensitivity of the organic electroluminescence device to electromagnetic waves can be increased and contrast can be obtained by irradiation with electromagnetic waves in a shorter time.

  Therefore, as a method for manufacturing an organic electroluminescent device and an organic electroluminescent device capable of forming a light emitting pattern more easily and providing a more efficient contrast, an organic electroluminescent device has not yet been satisfactory. At present, hole injection layer materials other than compounds having an amine skeleton cannot be used as hole injection layer materials for organic electroluminescence devices used for pattern formation.

Japanese Patent No. 2793373 Japanese Patent No. 3599077 JP 2000-133304 A JP 2000-348868 A

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention can easily contrast and reduce the manufacturing cost, and at the same time, a material other than a compound having an arylamine skeleton in the hole injection layer as an organic electroluminescence device used for patterning. The present invention is also applicable to a method for manufacturing an organic electroluminescent element and an organic electroluminescent element capable of expanding the range of material selection.

  As a result of intensive studies to achieve the above object, the present inventors have found that (1) there is a difference in photosensitivity to electromagnetic wave irradiation depending on the material of the hole injection layer, and (2) oxygen gas is used for the anode. As compared with the case where the surface treatment was performed, the knowledge that the increase in the driving voltage due to the electromagnetic wave exposure becomes remarkable when the surface treatment was performed using nitrogen gas or a rare gas.

This invention is based on the said knowledge by this inventor, and as a means for solving the said subject, it is as follows. That is,
<1> a surface treatment step of surface-treating the anode in a gas atmosphere containing at least one of nitrogen gas and rare gas;
An organic electroluminescence device producing step of producing an organic electroluminescence device comprising at least a hole injection layer and a light emitting layer on the surface-treated anode;
An electromagnetic wave irradiation step of changing the luminance of the light emitting surface by irradiating at least a part of the light emitting surface of the organic electroluminescent element;
It is the manufacturing method of the organic electroluminescent element characterized by including.
<2> The method for producing an organic electroluminescent element according to <1>, wherein the surface treatment is a plasma treatment.
<3> The method for producing an organic electroluminescent element according to <1>, wherein the surface treatment is an ultraviolet irradiation treatment.
<4> The method according to <1> to <3>, wherein the hole injection layer contains a compound having an arylamine skeleton.
<5> The hole injection layer contains an electron-accepting compound,
It is a manufacturing method of the organic electroluminescent element as described in said <1> to <4> in which content of the said electron-accepting compound has distribution in the thickness direction of the said positive hole injection layer.
<6> The organic electroluminescent element according to <1> to <4>, wherein the hole injection layer has a single layer structure, and includes a portion including the electron-accepting compound and a portion not including the electron-accepting compound in a thickness direction. It is a manufacturing method.
<7> The method for producing an organic electroluminescent element according to <6>, wherein the portion containing the electron-accepting compound is in contact with at least the anode of the hole injection layer.
<8> The method for producing an organic electroluminescent element according to any one of <6> to <7>, wherein the average thickness of the portion containing the electron-accepting compound is 20 nm or less.
<9> The organic electroluminescence according to <1> to <4>, wherein the hole injection layer has a multilayer structure, and a layer including the electron-accepting compound and a layer not including the electron-accepting compound are stacked in a thickness direction. It is a manufacturing method of an element.
<10> The method for producing an organic electroluminescent element according to <9>, wherein the layer containing the electron-accepting compound is in contact with at least the anode of the hole injection layer.
<11> The method for producing an organic electroluminescent element according to any one of <9> to <10>, wherein the average thickness of the layer containing the electron-accepting compound is 20 nm or less.
<12> An organic electroluminescence device produced by the method for producing an organic electroluminescence device according to any one of <1> to <11>.
<13> The organic electroluminescence device according to <12>, further including a layer that absorbs an electromagnetic wave having a wavelength irradiated in the electromagnetic wave irradiation step on the light emitting surface.

  According to the present invention, the conventional problems can be solved, the object can be achieved, contrast can be easily provided, and the manufacturing cost can be reduced. Provided is a method for manufacturing an organic electroluminescent device and a method for manufacturing an organic electroluminescent device that can apply materials other than a compound having an arylamine skeleton to the hole injection layer as a light emitting device, and can broaden the selection of materials. can do.

FIG. 1 is a graph showing voltage-luminance characteristics before and after electromagnetic wave irradiation in Example 1 of the present invention. FIG. 2 is a graph showing voltage-luminance characteristics before and after electromagnetic wave irradiation in Example 5 of the present invention.

(Method for manufacturing organic electroluminescent device)
The manufacturing method of the organic electroluminescent element of the present invention includes at least a surface treatment process, an organic electroluminescent element production process, and an electromagnetic wave irradiation process, and includes other processes as necessary.

The organic electroluminescent element has a pair of electrodes, that is, an anode and a cathode, and an organic layer including a light emitting layer and a hole injection layer between both electrodes, and has other layers depending on the purpose. Also good.
The organic layer includes at least a light emitting layer and a hole injection layer, and further includes a hole transport layer, an electron transport layer, a hole block layer, an electron block layer, an electron injection layer, and the like as necessary. May be.

  The organic electroluminescent element has a laminated structure in which a hole injection layer is provided on the anode. The hole transport layer is preferably provided between the stacked structure and the light emitting layer, and the electron transport layer is preferably provided between the cathode and the light emitting layer. The electron injection layer may be provided between the electron transport layer and the cathode. Further, a hole transporting intermediate layer (electron blocking layer) may be provided between the light emitting layer and the hole transporting layer, and an electron transporting intermediate layer (between the light emitting layer and the electron transporting layer ( A hole blocking layer) may be provided. Each organic layer may be divided into a plurality of secondary layers.

  Each organic layer including the light emitting layer can be formed according to a known method, and is suitable for, for example, a dry film forming method such as a vapor deposition method and a sputtering method, a wet coating method, a transfer method, a printing method, an ink jet method, and the like. Can be formed.

<Surface treatment process>
The surface treatment step is a step of surface-treating the anode in a gas atmosphere containing at least one of nitrogen gas and rare gas. It is known that an organic electroluminescent element not subjected to the surface treatment is inferior in durability, and the surface treatment is performed for the purpose of improving the durability of the organic electroluminescent element. In this invention, the effect that the drive voltage rises by the electromagnetic wave exposure mentioned later becomes remarkable by including this process which performs surface treatment in the gas atmosphere containing at least any one of nitrogen gas and a noble gas is acquired.

-Anode-
Examples of the material constituting the anode include tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Conductive metal oxides; metals such as gold, silver, chromium and nickel; mixtures or laminates of these metals and conductive metal oxides; inorganic conductive materials such as copper iodide and copper sulfide; polyaniline, polythiophene, Examples thereof include organic conductive materials such as polypyrrole, and laminates of these and conductive metal oxides. Among these, a conductive metal oxide is preferable, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like.

  The method for forming the anode is not particularly limited and can be performed according to a known method, for example, a wet method such as a printing method or a coating method; a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method. Chemical methods such as CVD and plasma CVD may be used. Of these, it can be formed on the substrate according to a method selected appropriately in consideration of suitability with the material constituting the anode. For example, when selecting ITO as the material of the anode, direct current or high frequency It can be formed by sputtering, vacuum deposition, ion plating, or the like. In addition, when selecting a metal etc. as a cathode material mentioned later, the 1 type (s) or 2 or more types can be formed by the sputtering method etc. simultaneously or sequentially.

  When patterning is performed when forming the anode, it may be performed by chemical etching using photolithography or the like, or by physical etching using a laser or the like. Further, the masks may be overlapped by vacuum steaming, sputtering, or the like, or by a lift-off method or a printing method.

-Gas containing at least one of nitrogen gas and rare gas-
Surface treatment is performed on the anode formed as described above using a gas containing at least one of the nitrogen gas and the rare gas. By performing the surface treatment using the nitrogen gas or the rare gas as a processing gas, a voltage increase due to electromagnetic wave exposure becomes remarkable even with the completely same element configuration, and an element that can be exposed in a short time can be obtained.

The rare gas includes helium, neon, argon, krypton, xenon, radon, and ununoctium. Among these, argon is preferable because of its low cost. These may be used individually by 1 type and may use 2 or more types together.
The nitrogen gas and the rare gas may be used by mixing with other gas such as oxygen. In this case, the content of the nitrogen gas or the rare gas is preferably 10% by mass or more, and more preferably 20% by mass or more. Is more preferable, and 40% by mass or more is particularly preferable. If the content is less than 10% by mass, the effect of conspicuous voltage increase during exposure may not be obtained.

-Surface treatment-
The surface treatment is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a known surface treatment method such as plasma treatment, various sputtering such as ion beam sputtering, ultraviolet irradiation treatment, radical beam treatment or the like may be used. Can be mentioned. Among these, plasma treatment and ultraviolet irradiation treatment are preferable because they can be processed in a short time and can be performed in various gas atmospheres.

  The plasma treatment can be appropriately selected as long as the substrate surface can be treated by converting the nitrogen gas or the rare gas into a plasma, but it is necessary to perform the treatment under conditions where the unevenness of the electrode surface is not increased by the plasma gas. It is. The condition that the unevenness of the electrode surface becomes larger than that before the treatment is not preferable, and there is a possibility that a short circuit between the electrodes is likely to occur when an organic electroluminescent element is formed.

  There is no restriction | limiting in particular as said ultraviolet treatment, Although it can select suitably according to the objective, As a wavelength of an ultraviolet-ray, 10 nm-400 nm are preferable. Specific examples of the ultraviolet light source include, for example, a high-pressure mercury lamp, a low-pressure mercury lamp, a hydrogen (deuterium) lamp, a rare gas (eg, xenon, argon, helium, neon) discharge lamp, a nitrogen laser, and an excimer laser (eg, , XeCl, XeF, KrF, KrCl, etc.), hydrogen laser, halogen laser, harmonics of various visible-infrared lasers, and the like.

<Organic electroluminescence device manufacturing process>
The organic electroluminescence device preparation step is a step of forming a hole injection layer and a light emitting layer on the surface of the anode surface-treated in the surface treatment step, and the step of forming the anode, the hole injection layer, and the light emitting layer. Is formed.
The organic electroluminescence device production process is not particularly limited and may be appropriately selected depending on the intended purpose. However, when exposed to the atmosphere, oxygen may be adsorbed. It is preferable to form each of the above layers without exposure to the atmosphere.

<< Hole Injection Layer >>
The hole injection layer is a layer having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. The hole injection layer may have a single layer structure or a multilayer structure composed of a plurality of layers having the same composition or different compositions.
The hole injection material may be a low molecular compound or a high molecular compound, and can be appropriately selected according to the purpose. For example, a pyrrole derivative, a carbazole derivative, a triazole derivative, or an oxazole derivative. , Oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic Group tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, phthalocyanine compounds, porphyrin compounds, thiophene derivatives, organosilane derivatives, carbon, etc. . Among these, arylamine derivatives are preferred in that the drive voltage is likely to increase due to electromagnetic wave exposure in an organic electroluminescent device using a material having an arylamine skeleton for the hole injection layer.
These may be used individually by 1 type and may use 2 or more types together.

  The method for forming the hole injection layer is not particularly limited, and a known method can be used.For example, a vapor deposition method, a dry film forming method such as a sputtering method, a wet coating method, a transfer method, a printing method, It can be suitably formed by an inkjet method or the like.

Specific examples of the hole injection material that can be used in the present invention include, but are not limited to, the following compounds.

The hole injection layer may be p-doped, and specifically contains an electron accepting compound.
The p-doped hole injection layer can be formed by co-evaporation of a hole injection material and an electron accepting compound.

The electron-accepting compound may be an inorganic compound or an organic compound as long as it has an electron-accepting property and oxidizes an organic compound.
Examples of the inorganic compound include metal halides such as ferric chloride, aluminum chloride, gallium chloride, indium chloride, and antimony pentachloride; metal oxides such as vanadium pentoxide and molybdenum trioxide.
Examples of the organic compound include compounds having a nitro group, a halogen, a cyano group, a trifluoromethyl group or the like as a substituent; quinone compounds, acid anhydride compounds, fullerenes, and the like.
These electron accepting compounds may be used alone or in combination of two or more.

The content of the electron-accepting compound varies depending on the type of material and cannot be uniquely determined, but is preferably 0.01% by mass to 50% by mass with respect to the hole injection layer material, and 0.05% by mass. % To 20% by mass is more preferable, and 0.1% to 10% by mass is particularly preferable.
When the content is within the preferable range, the number of carriers in the hole injection layer is increased, so that the hole injection property and the transport property are improved. On the other hand, if the content exceeds 50% by mass, the number of carriers may be decreased, resulting in a decrease in hole injection property and transport property, which is not preferable.

In the case where the hole injection layer contains the electron accepting compound, if the electron accepting compound is doped in the entire region of the hole injecting layer, the device does not increase the driving voltage even when exposed to electromagnetic waves. Therefore, it is preferable that an electron accepting compound is included in a part of the thickness direction of the hole injection layer, that is, the content of the electron accepting compound has a distribution in the thickness direction of the hole injection layer.
As the distribution of the content, for example, the hole injection layer may be a single layer, and may include a portion including the electron-accepting compound and a portion not including in the thickness direction of the layer. The hole injection layer may be a multi-layer stack, and may include a layer containing the electron accepting compound and a layer not containing the electron accepting compound.

  There is no restriction | limiting in particular as a part in the said hole injection layer containing the said electron-accepting compound, Although it can select suitably according to the objective, It is preferable to contact | connect at least the anode of a hole injection layer. By including the electron-accepting compound in the vicinity of the anode, it is possible to suppress the occurrence of unintended luminance unevenness in the element surface and to be an element capable of electromagnetic wave exposure.

  The average thickness of the portion containing the electron-accepting compound in the hole injection layer is not particularly limited as long as it does not cover the entire area of the hole injection layer, and can be appropriately selected according to the purpose. 20 nm or less is preferable. When the average thickness exceeds 20 nm, the drive voltage is hardly increased due to electromagnetic wave exposure.

<< Light emitting layer >>
The light emitting layer receives holes from an anode, a hole injection layer, or a hole transport layer when an electric field is applied, and receives electrons from any one of a cathode, an electron injection layer, and an electron transport layer. It is a layer having a function of providing a recombination field to emit light.
The light emitting layer includes a light emitting material. The light emitting layer may be composed only of a light emitting material, or may be a mixed layer of a host material and a light emitting material (in the latter case, the light emitting material may be referred to as a “light emitting dopant” or “dopant”).
Furthermore, the light emitting layer may contain a material that does not have charge transporting properties and does not emit light.

There is no restriction | limiting in particular as average thickness of the said light emitting layer, Although it can select suitably according to the objective, 2 nm-500 nm are preferable, 3 nm-200 nm are more preferable from a viewpoint of external quantum efficiency, and 5 nm-100 nm are preferable. Particularly preferred.
Moreover, the said light emitting layer may be 1 layer, or may be two or more layers, and each layer may light-emit with a different luminescent color.

-Luminescent material-
There is no restriction | limiting in particular as said luminescent material, According to the objective, it can select suitably, A fluorescent luminescent material may be sufficient and a phosphorescent luminescent material may be sufficient. Moreover, these may be used individually by 1 type and may use 2 or more types together.
The light emitting dopant has an ionization potential difference (ΔIp) and an electron affinity difference (ΔEa) of 1.2 eV>ΔIp> 0.2 eV and / or 1.2 eV>ΔEa> 0 with the host compound. A dopant satisfying the relationship of .2 eV is preferable from the viewpoint of driving durability.
The content of the light-emitting dopant in the light-emitting layer is preferably 0.1% by mass to 50% by mass with respect to the total compound mass generally forming the light-emitting layer in the light-emitting layer, and has durability and external quantum efficiency. From the viewpoint of 1% by mass to 50% by mass, more preferably 2% by mass to 40% by mass.

--Phosphorescent material--
There is no restriction | limiting in particular as said phosphorescence-emitting material, According to the objective, it can select suitably, The complex containing a transition metal atom or a lanthanoid atom, etc. are mentioned.
There is no restriction | limiting in particular as said transition metal atom, According to the objective, it can select suitably, For example, ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold | metal | money, silver, copper, platinum etc. are mentioned. Among these, rhenium, iridium, and platinum are preferable, and iridium and platinum are particularly preferable.

  Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Examples include ligands described in Yersin's "Photochemistry and Photophysics of Coordination Compounds" published by Springer-Verlag 1987, Akio Yamamoto "Organic Metal Chemistry-Fundamentals and Applications-" .

  The complex may have one transition metal atom in the compound or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

Examples of the phosphorescent material include, for example, US Pat. No. 6,303,238, US Pat. No. 6,097,147, WO00 / 57676, WO00 / 70655, WO01 / 08230, WO01 / 39234, WO01. / 41512 pamphlet, WO02 / 02714 pamphlet, WO02 / 15645 pamphlet, WO02 / 44189 pamphlet, WO05 / 19373 pamphlet, WO2004 / 108857 pamphlet, WO2005 / 042444 pamphlet, WO2005 / 042550 pamphlet, JP2001. JP-A No. 247859, JP-A No. 2002-302671, JP-A No. 2002-117978, and JP-A No. 2003. JP 133074, JP 2002-235076, JP 2003-123982, JP 2002-170684, EP 12111257, JP 2002-226495, JP 2002-234894, special JP-A-2001-247859, JP-A-2001-298470, JP-A-2002-173675, JP-A-2002-203678, JP-A-2002-203679, JP-A-2004-357791, JP-A-2006 Phosphorescence described in JP-A No. 93542, JP-A 2006-261623, JP-A 2006-256999, JP-A 2007-19462, JP-A 2007-84635, JP-A 2007-96259, and the like. Compound etc. are mentioned.
Among these, Ir complex, Pt complex, Cu complex, Re complex, W complex, Rh complex, Ru complex, Pd complex, Os complex, Eu complex, Tb complex, Gd complex, Dy complex, and Ce complex are preferable, and Ir complex Pt complex and Re complex are more preferable, Ir complex including at least one coordination mode of metal-carbon bond, metal-nitrogen bond, metal-oxygen bond and metal-sulfur bond, Pt complex, and Re complex are more preferable. From the viewpoints of luminous efficiency, driving durability, chromaticity, and the like, Ir complexes, Pt complexes, and Re complexes containing a tridentate or higher polydentate ligand are particularly preferable.

  Specific examples of the phosphorescent material that can be used in the present invention include, but are not limited to, the following compounds.

--Fluorescent material--
The fluorescent material is not particularly limited and can be appropriately selected according to the purpose. For example, benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, Coumarin, pyran, perinone, oxadiazole, aldazine, pyralidine, cyclopentadiene, bisstyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, cyclopentadiene, styrylamine, aromatic dimethylidin compounds, condensed polycyclic aromatic compounds (for example, , Anthracene, phenanthroline, pyrene, perylene, rubrene, or pentacene), 8-quinolinol metal complexes; various metal complexes typified by pyromethene complexes and rare earth complexes; poly Thiophene, polyphenylene, polymeric compounds such as polyphenylene vinylene; organic silane, and derivatives thereof. These may be used individually by 1 type and may use 2 or more types together.

-Host material-
The host material is preferably a charge transport material.
As the charge transporting material, a hole transporting host material having excellent hole transporting property and an electron transporting host material having excellent electron transporting property can be used.

--Hole-transporting host material--
The hole transporting host material is not particularly limited and may be appropriately selected depending on the purpose. For example, pyrrole, indole, carbazole, azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole, Imidazole, thiophene, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine compound, aromatic dimethylidin compound , Porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organosilanes Carbon film, or a derivative thereof, and the like. These may be used individually by 1 type and may use 2 or more types together.
Among these, indole derivatives, carbazole derivatives, aromatic tertiary amine compounds, and thiophene derivatives are preferable, those having a carbazole group in the molecule are more preferable, and compounds having a t-butyl-substituted carbazole group are particularly preferable.

--- Electron transport host material-
The electron transporting host material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include pyridine, pyrimidine, triazine, imidazole, pyrazole, triazole, oxazole, oxadiazol, and fluorenone. , Anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, fluorine-substituted aromatic compounds, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene; phthalocyanines or their derivatives (It may form a condensed ring with other rings), metal complexes of 8-quinolinol derivatives, various metal complexes represented by metal complexes having metal phthalocyanine, benzoxazole and benzothiazol as ligands Etc. These may be used individually by 1 type and may use 2 or more types together.
Among these, from the viewpoint of durability, a metal complex compound is preferable, and a metal complex having a ligand having at least one nitrogen atom, oxygen atom, or sulfur atom coordinated to a metal is more preferable.
Examples of the metal complex compound include Japanese Patent Application Laid-Open No. 2002-235076, Japanese Patent Application Laid-Open No. 2004-214179, Japanese Patent Application Laid-Open No. 2004-221106, Japanese Patent Application Laid-Open No. 2004-221106, Japanese Patent Application Laid-Open No. 2004-221068, Examples thereof include compounds described in JP-A No. 2004-327313.

  Examples of the hole transporting host material and the electron transporting host material that can be used in the present invention include the following compounds and deuterated compounds thereof, but are not limited thereto.

<Electromagnetic wave irradiation process>
The electromagnetic wave irradiating step is a step of irradiating at least a part of the light emitting surface of the organic electroluminescent element with electromagnetic waves to change the luminance in the light emitting surface of the organic electroluminescent element.
Irradiation with electromagnetic waves changes the element characteristics of the exposed portion and can increase the drive voltage, so that the luminance of the light emitting surface can be partially changed to any brightness. In addition, since the difference in luminance between the exposed part and the unexposed part can be given by the electromagnetic wave irradiation, that is, a contrast can be given, the electromagnetic wave irradiation can be performed in an arbitrary pattern on the light emitting surface of organic electroluminescence. It is possible to form a luminance pattern.

The electromagnetic wave used in the present invention has a vacuum wavelength in the range of about 10 ⁻¹⁷ to 10 ⁵ m, and includes γ rays, X rays, ultraviolet rays, visible rays, infrared rays, and the like. Among these, ultraviolet rays or visible rays are preferable.
Examples of the electromagnetic wave irradiation apparatus include a high-pressure mercury lamp, a low-pressure mercury lamp, a hydrogen (deuterium) lamp, a rare gas (xenon, argon, helium, neon, etc.) discharge lamp, a nitrogen laser, and an excimer laser (for example, XeCl, XeF). , KrF, KrCl, etc.), hydrogen laser, halogen laser, various harmonics of visible-infrared laser, and the like.

  Electromagnetic wave irradiation to the organic electroluminescence device is (i) when the irradiation intensity is changed over the entire surface (for example, exposure through a filter having partially different transmittance such as a black and white negative film, or generated from a minute light source) For example, scanning may be performed while changing the irradiation intensity of light) or (b) partial irradiation may be performed by masking. In the case of partial exposure, for example, contact exposure using a shadow mask or projection exposure (partial exposure using light condensed by a lens or light generated from a minute light source) This is implemented by using a shadow mask together.

Examples of the electromagnetic wave amount is not particularly limited, as appropriate may be ^{selected, 1J / cm 2 ~10,000J / cm} 2 are preferred according to the ^{purpose, 5J / cm 2 ~1,000J / cm} 2 Gayori preferable. When the irradiation time is less than 1 J / cm ² , the voltage rise is insufficient, and the exposed portion and the unexposed portion may not be contrasted. When the irradiation time exceeds 10,000 J / cm ² , the drive voltage In addition to the rise, the entire device may be deteriorated.

<Other processes>
The method for producing an organic electroluminescent element of the present invention includes, as other steps, a hole transport layer, a hole transport intermediate layer (electron block layer), which are selected according to the purpose, on the hole injection layer, You may further include the process of arrange | positioning each functional layer of an electron transport intermediate | middle layer (hole block layer), an electron carrying layer, and an electron injection layer, and a cathode.

<< Hole Transport Layer >>
The hole transport layer is a layer having a function of receiving holes from the anode or the anode side and transporting them to the cathode side together with the hole injection layer.
The hole transport layer may have a single layer structure or a multilayer structure composed of a plurality of layers having the same composition or different compositions.
Examples of the material for the hole transport layer and the electron-accepting compound to be contained include the same materials as those for the hole injection layer.

<< Electron injection layer, electron transport layer >>
The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injecting material and the electron transporting material used for these layers may be low molecular compounds or high molecular compounds. Specifically, pyridine derivatives, quinoline derivatives, pyrimidine derivatives, pyrazine derivatives, phthalazine derivatives. , Phenanthroline derivative, triazine derivative, triazole derivative, oxazole derivative, oxadiazole derivative, imidazole derivative, fluorenone derivative, anthraquinodimethane derivative, anthrone derivative, diphenylquinone derivative, thiopyrandioxide derivative, carbodiimide derivative, fluorenylidenemethane Derivatives, distyrylpyrazine derivatives, aromatic tetracarboxylic anhydrides such as naphthalene and perylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives and metal phthalocyanines, benzoo Sasol to various metal complexes typified benzothiazole by metal complexes having a ligand, an organic silane derivatives typified by silole is preferred.

The electron injection layer and the electron transport layer may contain an electron donating dopant.
The electron-donating dopant introduced into the electron-injecting layer and the electron-transporting layer is not limited as long as it has an electron-donating property and has a property of reducing an organic compound, such as an alkali metal such as Li or an alkaline earth metal such as Mg. Transition metals including rare earth metals, reducing organic compounds, and the like are preferably used. As the metal, a metal having a work function of 4.2 eV or less can be preferably used. Specifically, Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Examples thereof include Gd and Yb. Examples of the reducing organic compound include nitrogen-containing compounds, sulfur-containing compounds, and phosphorus-containing compounds.
These electron donating dopants may be used alone or in combination of two or more.
The content of the electron donating dopant varies depending on the type of material, but is preferably 0.1% by mass to 99% by mass, and 1.0% by mass to 80% by mass with respect to the electron transport layer material. More preferably, it is particularly preferably 2.0% by mass to 70% by mass.

  The electron injection layer and the electron transport layer may have a single layer structure made of one or more of the materials described above, or a multilayer structure made of a plurality of layers having the same composition or different compositions. Good.

<< Hole Block Layer, Electron Block Layer >>
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side, and is usually provided as an organic compound layer adjacent to the light emitting layer on the cathode side. .
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side, and is usually provided as an organic compound layer adjacent to the light emitting layer on the anode side.
Examples of the compound constituting the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, and phenanthroline derivatives such as BCP.
As a compound which comprises the said electron block layer, what was mentioned as the above-mentioned hole transport material can be utilized, for example.
The thickness of the hole blocking layer and the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and particularly preferably 10 nm to 100 nm. In addition, the hole blocking layer and the electron blocking layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. .

<< Electrode >>
The organic electroluminescent element includes a pair of electrodes, that is, an anode and a cathode. In view of the nature of the organic electroluminescence device, at least one of the anode and the cathode is preferably transparent. Usually, the anode only needs to have a function as an electrode for supplying holes to the organic compound layer, and the cathode only needs to have a function as an electrode for injecting electrons into the organic compound layer.
There is no restriction | limiting in particular about the shape, a structure, a magnitude | size, etc. as said electrode, According to the use and objective of an organic electroluminescent element, it can select suitably from well-known electrode materials.
As a material which comprises the said electrode, a metal, an alloy, a metal oxide, a conductive compound, or a mixture thereof etc. are mentioned suitably, for example.

-Anode-
The anode is formed in the same manner as the anode in the present invention.

-Cathode-
Examples of the material constituting the cathode include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, Examples thereof include lithium-aluminum alloys, magnesium-silver alloys, rare earth metals such as indium and ytterbium. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.
Among these, alkali metals and alkaline earth metals are preferable from the viewpoint of electron injection properties, and materials mainly composed of aluminum are preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, an alloy of aluminum and 0.01% by mass to 10% by mass of alkali metal or alkaline earth metal, or a mixture thereof (for example, lithium-aluminum alloy, magnesium-aluminum). Alloy).

  The method for forming the cathode and the patterning for forming the cathode can be performed in the same manner as the anode.

<< Board >>
The organic electroluminescent element is preferably provided on a substrate, and may be provided in such a manner that the electrode and the substrate are in direct contact with each other, or may be provided with an intermediate layer interposed therebetween.
The material for the substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, inorganic materials such as yttria-stabilized zirconia (YSZ) and glass (such as alkali-free glass and soda lime glass); polyethylene terephthalate And polyesters such as polybutylene phthalate and polyethylene naphthalate; organic materials such as polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, polycycloolefin, norbornene resin, and poly (chlorotrifluoroethylene).

  There is no restriction | limiting in particular about the shape of the said board | substrate, a structure, a magnitude | size, According to the use of a light emitting element, the objective, etc., it can select suitably. In general, the shape of the substrate is preferably a plate shape. The structure of the substrate may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members. Good. The substrate may be transparent or opaque, and if transparent, it may be colorless and transparent or colored and transparent.

The substrate may be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
Examples of the material of the moisture permeation preventing layer (gas barrier layer) include inorganic substances such as silicon nitride and silicon oxide.
The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.

<< Protective layer >>
The entire organic electroluminescent element may be protected by a protective layer.
The material contained in the protective layer is not particularly limited as long as it has a function of suppressing the entry of elements that promote element deterioration such as moisture and oxygen into the element. For example, metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, Ni; MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, Fe Metal oxides such as ₂ O ₃ , Y ₂ O ₃ and TiO ₂ ; Metal nitrides such as SiNx and SiNxOy; Metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ ; polyethylene, polypropylene, polymethyl methacrylate, Polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, chlorotrifluoroethylene And a copolymer of dichlorodifluoroethylene, a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer, a fluorine-containing copolymer having a cyclic structure in the copolymer main chain, Examples thereof include a water-absorbing substance having a water absorption rate of 1% or more and a moisture-proof substance having a water absorption rate of 0.1% or less.

  There is no restriction | limiting in particular as a formation method of the said protective layer, According to the objective, it can select suitably, For example, a vacuum evaporation method, sputtering method, reactive sputtering method, MBE (molecular beam epitaxy) method, cluster ion beam Examples thereof include an ion plating method, a plasma polymerization method (high frequency excitation ion plating method), a plasma CVD method, a laser CVD method, a thermal CVD method, a gas source CVD method, a coating method, a printing method, and a transfer method.

-Sealing container-
The organic electroluminescent element may be entirely sealed using a sealing container. Furthermore, a moisture absorbent or an inert liquid may be sealed in the space between the sealing container and the organic electroluminescent element.
The moisture absorbent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, Examples thereof include calcium chloride, magnesium chloride, copper chloride, cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, and magnesium oxide.
The inert liquid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include paraffins, liquid paraffins; fluorinated solvents such as perfluoroalkane, perfluoroamine, and perfluoroether; chlorine System solvents, silicone oils and the like.

-Resin sealing layer-
The organic electroluminescent element is preferably suppressed by sealing the element performance deterioration due to oxygen or moisture from the atmosphere with a resin sealing layer.
The resin material of the resin sealing layer is not particularly limited and may be appropriately selected depending on the purpose. For example, acrylic resin, epoxy resin, fluorine resin, silicone resin, rubber resin, ester resin Etc. Among these, an epoxy resin is particularly preferable from the viewpoint of moisture prevention function. Among the epoxy resins, a thermosetting epoxy resin or a photocurable epoxy resin is preferable.

  There is no restriction | limiting in particular as a preparation method of the said resin sealing layer, According to the objective, it can select suitably, For example, the method of apply | coating a resin solution, the method of crimping | bonding or thermocompressing a resin sheet, vapor deposition, sputtering, etc. And a dry polymerization method.

-Sealing adhesive-
The sealing adhesive used for the organic electroluminescent element has a function of preventing intrusion of moisture and oxygen from the end portion.
As the material of the sealing adhesive, the same material as that used for the resin sealing layer can be used. Among these, an epoxy adhesive is preferable from the viewpoint of moisture prevention, and a photocurable adhesive or a thermosetting adhesive is particularly preferable.
It is also preferable to add a filler to the sealing adhesive. As the filler, for example _SiO 2, SiO (silicon oxide), SiON (silicon oxynitride), an inorganic material such as SiN (silicon nitride) are preferred. Addition of the filler increases the viscosity of the sealing adhesive, improves processing suitability, and improves moisture resistance.
The sealing adhesive may contain a desiccant. Examples of the desiccant include barium oxide, calcium oxide, and strontium oxide. The addition amount of the desiccant is preferably 0.01% by mass to 20% by mass and more preferably 0.05% by mass to 15% by mass with respect to the sealing adhesive. When the addition amount is less than 0.01% by mass, the effect of adding the desiccant is diminished, and when it exceeds 20% by mass, it is difficult to uniformly disperse the desiccant in the sealing adhesive. Sometimes.
In the present invention, it is possible to seal by applying an arbitrary amount of a sealing adhesive containing a desiccant in the previous period with a dispenser or the like, and stacking and curing the second substrate after application.

-Drive-
The organic electroluminescent element emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. be able to.
The organic electroluminescence device can be applied to an active matrix by a thin film transistor (TFT). As the active layer of the thin film transistor, amorphous silicon, high temperature polysilicon, low temperature polysilicon, microcrystalline silicon, oxide semiconductor, organic semiconductor, carbon nanotube, or the like can be used.
As the organic electroluminescent element, for example, a thin film transistor described in WO2005 / 088826 pamphlet, JP-A-2006-165529, US Patent Application Publication No. 2008 / 0237598A1, and the like can be applied.

The organic electroluminescent element is not particularly limited, and the light extraction efficiency can be improved by various known devices. For example, processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate, ITO layer, organic layer, controlling the film thickness of the substrate, ITO layer, organic layer Thus, the light extraction efficiency can be improved and the external quantum efficiency can be improved.
The light extraction method from the organic electroluminescent element may be a top emission method or a bottom emission method.

The organic electroluminescent device may have a resonator structure. For example, a multilayer mirror made of a plurality of laminated films having different refractive indexes, a transparent or translucent electrode, a light emitting layer, and a metal electrode are superimposed on a transparent substrate. The light generated in the light emitting layer resonates repeatedly with the multilayer mirror and the metal electrode as a reflection plate.
In another preferred embodiment, a transparent or translucent electrode and a metal electrode each function as a reflecting plate on a transparent substrate, and light generated in the light emitting layer repeats reflection and resonates between them.
In order to form a resonant structure, the optical path length determined from the effective refractive index of the two reflectors and the refractive index and thickness of each layer between the reflectors is adjusted to an optimum value to obtain the desired resonant wavelength. Is done. The calculation formula in the case of the first aspect is described in JP-A-9-180883. The calculation formula in the case of the second aspect is described in Japanese Patent Application Laid-Open No. 2004-127795.

-Application-
The organic electroluminescent element is not particularly limited and may be appropriately selected depending on the intended purpose. Display element, display, backlight, electrophotography, illumination light source, recording light source, exposure light source, reading light source, sign, signboard It can be suitably used for interior, optical communication, and the like.
As a method for making the organic EL display of a full color type, as described in, for example, “Monthly Display”, September 2000, pages 33 to 37, the three primary colors (blue (B), green (G), red (R)) three-color light emission method in which organic electroluminescent elements that emit light respectively corresponding to red (R) are arranged on a substrate, white light emission by a white light-emitting organic electroluminescent element to three primary colors through a color filter There are known a white method of dividing, a color conversion method of converting blue light emission by an organic electroluminescent element for blue light emission into red (R) and green (G) through a fluorescent dye layer. Moreover, the planar light source of a desired luminescent color can be obtained by using combining the organic electroluminescent element of the different luminescent color obtained by the said method. For example, a white light-emitting light source combining blue and yellow light-emitting elements, a white light-emitting light source combining blue, green, and red light-emitting elements can be used.

(Organic electroluminescence device)
The organic electroluminescent element of the present invention is manufactured by the method for manufacturing an organic electroluminescent element of the present invention.

  The organic electroluminescence device has a pair of electrodes, that is, an anode and a cathode, and an organic layer including a light emitting layer and a hole injection layer between the electrodes, and further, if necessary, a hole transport layer, an electron You may have a transport layer, a hole block layer, an electron block layer, an electron injection layer, etc.

  The organic electroluminescent element has a laminated structure in which a hole injection layer is provided on an anode. A hole transport layer is preferably provided between the stacked structure and the light emitting layer, and an electron transport layer is preferably provided between the cathode and the light emitting layer. An electron injection layer may be provided between the electron transport layer and the cathode. Further, a hole transporting intermediate layer (electron blocking layer) may be provided between the light emitting layer and the hole transporting layer, and an electron transporting intermediate layer (hole blocking layer) between the light emitting layer and the electron transporting layer. ) May be provided. Each organic layer may be divided into a plurality of secondary layers.

As each organic layer including the electrode, the light emitting layer, and the hole injection layer, all of the configurations described in the method for manufacturing the organic electroluminescent element of the present invention can be applied.
The manufacturing method of this invention may further include the absorption layer installation process.

The organic electroluminescent element exposed by the electromagnetic wave irradiation step may have a layer that absorbs the electromagnetic wave having the wavelength irradiated in the electromagnetic wave irradiation step on the light emitting surface.
The organic electroluminescence device exposed in the electromagnetic wave irradiation step is exposed to light including a specific wavelength from the outside on the light emitting surface of the organic electroluminescence device because sensitivity to the wavelength of the irradiated electromagnetic wave increases. In some cases, the luminance may decrease. Therefore, in order to prevent unintended exposure, it is preferable to provide a layer that absorbs the electromagnetic wave having the wavelength irradiated in the electromagnetic wave irradiation step on the light emitting surface of the organic electroluminescent element.

There is no restriction | limiting in particular as a layer which absorbs the said electromagnetic wave, According to the wavelength to absorb, it can select suitably, For example, a filter, a film, etc. are mentioned.
There is no restriction | limiting in particular as a method of installing the said layer, According to the objective, it can select suitably, For example, you may wrap the whole organic electroluminescent element, and it covers the light emission surface of an organic electroluminescent element. It may be covered.

Examples of the present invention will be described below, but the present invention is not limited to these examples. (Replace the following Examples 1-10 and 13-15 with Reference Examples 1-10 and 13-15)

Example 1
<Production of organic electroluminescence device>
A glass substrate with ITO of 100 nm thickness (substrate thickness 0.7 mm, Super Flat ITO manufactured by Geomatek Co., Ltd.) was washed and dried sufficiently, and then the ITO surface was replaced with an EXAM type plasma cleaning device (manufactured by Shinko Seiki Co., Ltd.). The substrate was used for surface treatment. Nitrogen gas was used as the processing gas. As the surface treatment conditions, the output of the high-frequency power source was 80 W, the gas flow rate was 70 mL / min, and the treatment time was 60 seconds. The pressure during the treatment was 100 Pa. Next, the substrate was placed in a vacuum deposition apparatus (CM470 manufactured by Tokki Co., Ltd.), and CuPc (copper phthalocyanine) represented by the following structural formula was deposited by 40 nm. Next, α-NPD [N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine] was deposited by 10 nm. Next, CBP [4,4′-bis [9-dicarbazolyl] -2 doped with 12% by mass of Ir (mppy) 3 [tris [2- (p-tolyl) pyridine] iridium (III)] as a light emitting layer, 2′-biphenyl] was vapor-deposited to 30 nm, and Alq3 [tris (8-hydroxyquinolinato) aluminum (III)] was vapor-deposited to 50 nm. The vapor deposition rate was 0.2 nm / s. Next, 1 nm of LiF (lithium fluoride) was vapor-deposited, and finally, 100 nm of Al (aluminum) as a cathode was laminated by vapor deposition. The deposition rate of LiF was 0.02 nm / s, and the deposition rate of Al was 1 nm / s. Next, the sealing glass was adhered using a UV curable adhesive (XNR5516Z manufactured by Nagase ChemteX Corporation) to obtain an organic electroluminescent element having a light emitting area of 2 mm × 2 mm. In addition, the vapor deposition rate and each layer thickness were measured using the quartz oscillator.

The structure of the organic electroluminescence device finally obtained is as follows: from the anode side, ITO (100 nm) / CuPc (40 nm) / NPD (10 nm) / 12 mass% Ir (mppy) 3 + CBP (30 nm) / Alq3 (50 nm) / LiF (1 nm) / Al (100 nm). The structural formulas of CuPc, NPD, CBP, Ir (mppy) 3, and Alq3 are shown below.

The entire 2 mm square light emitting surface obtained above was irradiated with electromagnetic waves (280 mW / cm ² ) from a xenon mercury lamp for 10 minutes.

<Measurement method>
The luminance and emission start voltage of the obtained organic electroluminescence device were measured as follows.

-Measurement of luminance of organic electroluminescent element-
About the organic electroluminescent element before and behind electromagnetic wave irradiation, the direct voltage was applied to the element and light-emitted using the source measure unit SMU-1 by Keithley Instruments Inc. (Keithley Instruments Inc.). The brightness was measured using SR-3 manufactured by Topcon Corporation. FIG. 1 shows changes in voltage-luminance characteristics due to electromagnetic wave irradiation.
Moreover, the brightness | luminance at the time of 10V application was compared from the voltage-luminance characteristic before and behind electromagnetic wave irradiation. The results are shown in Table 1. In addition, the luminance change rate before and after electromagnetic wave irradiation was calculated | required by following formula (1).
Brightness change rate (%) = [(luminance not irradiated with electromagnetic wave−luminance after electromagnetic wave irradiation) / luminance not irradiated with electromagnetic wave] × 100 (1)

-Measurement of drive voltage-
Using a source measure unit SMU-1 manufactured by Keithley Instruments Inc., direct current was passed through each element to emit light. At this time, a voltage required to start light emission was defined as a drive voltage (V).

(Comparative Example 1)
In Example 1, an organic electroluminescent element was produced and evaluated in the same manner as in Example 1 except that the gas used for electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 2)
In Example 1, an organic electroluminescence device was produced and evaluated in the same manner as in Example 1 except that the material of the hole injection layer was changed from CuPc to Ir (mppy) 3.

(Comparative Example 2)
In Example 2, an organic electroluminescent element was produced and evaluated in the same manner as in Example 2 except that the gas used for the electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 3)
In Example 1, the material of the hole injection layer was changed from CuPc to m-MTDATA [4,4 ′, 4 ″ -nitrilotris [N- (3-methylphenyl) -N-phenylaniline represented by the following structural formula. ] An organic electroluminescent element was produced and evaluated in the same manner as in Example 1 except that the above was changed.

(Comparative Example 3)
In Example 3, an organic electroluminescent element was produced and evaluated in the same manner as in Example 3 except that the gas used for the electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 4)
In Example 1, the material of the hole injection layer was changed from CuPc to DNTPD [N, N′-diphenyl-N, N′-bis- [4- (phenyl-m-tolyl-amino)-] represented by the following structural formula. An organic electroluminescent device was prepared and evaluated in the same manner as in Example 1 except that the compound was changed to [phenyl] -biphenyl-4,4′-diamine].

(Comparative Example 4)
In Example 4, an organic electroluminescent element was produced and evaluated in the same manner as in Example 4 except that the gas used for the electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 5)
In Example 1, the material of the hole injection layer was changed from CuPc to 2-TNATA [4,4 ′, 4 ″ -tris [N, N- (2-naphthyl) phenylamino] triphenyl represented by the following structural formula. An organic electroluminescent element was produced and evaluated in the same manner as in Example 1 except that the amine was changed to [Amine]. In addition, the change of the voltage-luminance characteristic by electromagnetic wave irradiation is shown in FIG.

(Example 6)
In Example 5, an organic electroluminescent element was produced in the same manner as in Example 5 except that the gas used for the electrode surface treatment was changed from nitrogen gas to nitrogen / oxygen mixed gas (volume ratio = 1/1). Evaluation was performed.

(Example 7)
In Example 5, an organic electroluminescent element was produced and evaluated in the same manner as in Example 5 except that the gas used for the electrode surface treatment was changed from nitrogen gas to argon gas.

(Example 8)
In Example 5, an organic electroluminescent element was prepared and evaluated in the same manner as in Example 5 except that the gas used for the electrode surface treatment was changed from nitrogen gas to xenon gas.

(Comparative Example 5)
In Example 5, an organic electroluminescent element was produced and evaluated in the same manner as in Example 5 except that the gas used for electrode surface treatment was changed from nitrogen gas to oxygen gas.

Example 9
In Example 7, an organic electroluminescent element was produced and evaluated in the same manner as in Example 5 except that the surface treatment of the electrode was changed from the plasma treatment to the ultraviolet irradiation treatment in which ultraviolet rays were irradiated for 20 minutes. In addition, ultraviolet irradiation uses a gas flow amount of 1 L / min. It went on condition of.

(Example 10)
In Example 9, an organic electroluminescent element was produced in the same manner as in Example 9 except that the gas used for the electrode surface treatment was changed from nitrogen gas to nitrogen / oxygen mixed gas (volume ratio = 8/2). Evaluation was performed.

(Comparative Example 6)
In Example 9, an organic electroluminescent element was produced and evaluated in the same manner as in Example 9 except that the gas used for the electrode surface treatment was changed from argon gas to oxygen gas.

(Example 11)
In Example 1, instead of depositing 40 nm of CuPc on ITO, an electron-accepting compound represented by the following structural formula (F4TCQN: 2, 3, 5, An organic electroluminescent device was prepared and evaluated in the same manner as in Example 1 except that 5-TNAF doped with 6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) was evaporated. went. Note that the hole injection layer doped with the electron accepting compound was formed by co-evaporation of the hole injecting material and the electron accepting compound. The content of the electron-accepting compound was set to 0.3% by mass by setting the deposition rate of 2-TNATA to 0.5 nm / s and the deposition rate of F4TCNQ to 0.0015 nm / s.

(Comparative Example 7)
In Example 11, an organic electroluminescent element was produced and evaluated in the same manner as in Example 11 except that the gas used for the electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 12)
In Example 11, the organic layer was organically treated in the same manner as in Example 11 except that the deposition order was changed so that 2-TNATA doped with 0.3% by mass of F4TCQN was deposited to 5 nm and then 2-TNATA was deposited to 35 nm. An electroluminescent element was prepared and evaluated.

(Comparative Example 8)
In Example 12, an organic electroluminescent element was produced and evaluated in the same manner as in Example 12 except that the gas used for the electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Example 13)
In Example 1, instead of depositing 40 nm of CuPc on ITO, 40 nm of 2-TNATA doped with 0.3% by mass of F4TCNQ was deposited on ITO, and the irradiation time of electromagnetic waves was changed from 10 minutes to 200 minutes. An organic electroluminescent element was produced and evaluated in the same manner as in Example 1.

(Comparative Example 9)
In Example 13, an organic electroluminescent element was produced and evaluated in the same manner as in Example 13 except that the gas used for electrode surface treatment was changed from nitrogen gas to oxygen gas.

(Comparative Example 10)
In Example 1, an organic electroluminescent element was produced and evaluated in the same manner as in Example 1 except that the electrode surface treatment was not performed.

(Example 14)
An organic electroluminescent element was produced in the same manner as in Example 5. An ultraviolet cut filter (SC-42 manufactured by Fuji Film Co., Ltd.) was attached to the resulting device, and stored for 1 month in a bright place (under fluorescent light, 1000 lux environment). Table 2 shows the luminance when 10 V was applied before and after storage.

(Example 15)
An organic electroluminescent element was produced in the same manner as in Example 5. The obtained device was stored in a bright place for 1 month (under a fluorescent lamp, 1000 lux environment). Table 2 shows the luminance when 10 V was applied before and after storage.

  The results of various evaluations described above in Examples 1 to 15 and Comparative Examples 1 to 10 are shown in Tables 1 and 2 below.

From FIG. 1, it can be seen that in the organic electroluminescent device containing CuPc in the hole injection layer, the driving voltage of the device was increased by the electromagnetic wave irradiation. Brightness in 10V applied, was 200 cd / ^{m 2} at element was electromagnetic radiation at the element not subjected to electromagnetic radiation 450 cd ^/ m 2, 10 minutes. In addition, the luminance under equal voltage driving was increased 0.31 times by electromagnetic wave irradiation for 10 minutes.
The CuPc is useful as a hole injection layer material of an organic electroluminescence device because it has a low emission starting voltage compared to the case where a material having an arylamine skeleton is used. As a hole injection layer material of an organic electroluminescence device for exposing a pattern with an electromagnetic wave, it has been considered that it cannot usually be used. However, it can be seen that by using nitrogen gas or rare gas as the surface treatment gas for the anode, CuPc can be sufficiently used as the hole injection layer material of such an organic electroluminescence device.

  From FIG. 2, it can be seen that in the organic electroluminescent device containing 2-TNATA, which is a compound having an arylamine skeleton, in the hole injection layer, the driving voltage of the device is increased by irradiation with electromagnetic waves. The increase rate is larger than when CuPc is used as the hole injection layer material, and the hole injection layer material having an arylamine skeleton is highly sensitive to electromagnetic wave irradiation.

  As can be seen from Table 1, if the hole injection layer is the same material, the use of nitrogen gas or noble gas for the surface treatment of the anode can increase the driving voltage even with the same electromagnetic wave irradiation amount. Thus, an organic electroluminescence device capable of obtaining a large contrast by irradiation with electromagnetic waves for a short time could be manufactured. In addition, by using m-MTDATA, DNTPD, and 2-TNATA containing an arylamine skeleton in the hole injection layer, it is possible to change the driving voltage with shorter electromagnetic wave irradiation, and the organic pattern is used for drawing a pattern by exposure. It has been found to be advantageous as an electroluminescent device.

  Further, it can be seen from Table 1 that the element of Example 13 in which the electron-accepting compound is contained in the whole hole injection layer is an element that requires electromagnetic wave irradiation for a very long time in order to increase the drive voltage. On the other hand, in Examples 11 and 12, the organic electroluminescent element was reduced in voltage by partially containing an electron-accepting compound (the luminance at 10 V was higher than that in Example 5). Thus, the device can be exposed in a short time.

  From Comparative Example 10, when the surface treatment of the anode is not performed, the drive voltage due to exposure is likely to increase as compared with the case where the surface treatment is performed with oxygen gas, but the drive voltage of the original device as a whole is high and the electric efficiency is high. It turns out that becomes a very low element. In addition, it is known that an organic electroluminescence device not subjected to surface treatment is inferior in device performance, and the performance as a device becomes very low regardless of exposure.

  Further, as can be seen from Table 2, unintentional exposure can be prevented by providing a layer that absorbs a specific wavelength, such as a filter, on the light emitting surface of the element after the organic electroluminescent element is manufactured.

The organic electroluminescent device manufactured by the method for manufacturing an organic electroluminescent device of the present invention can increase the driving voltage of the irradiated portion effectively even for a short time of electromagnetic wave irradiation, and thus can easily provide contrast. In addition, the manufacturing cost can be reduced.
In addition, it is possible to use a material other than the material having an arylamine skeleton in the hole injection layer of the exposure organic electroluminescence device, and the range of material selection can be expanded. In particular, an organic electroluminescent element using CuPc and Ir (mppy) 3 is advantageous in terms of luminous efficiency because it has a lower driving voltage than an organic electroluminescent element using a material having an arylamine skeleton.

Claims (8)

A surface treatment step of surface-treating the anode in a gas atmosphere containing at least one of nitrogen gas and noble gas;
An organic electroluminescence device producing step of producing an organic electroluminescence device comprising at least a hole injection layer and a light emitting layer on the surface-treated anode;
Look including a electromagnetic wave irradiating step of changing the brightness of the light emitting surface by irradiating an electromagnetic wave to at least a portion of the light emitting surface of the organic light emitting diode,
The hole injection layer contains an electron-accepting compound;
The method for producing an organic electroluminescent element , wherein the content of the electron-accepting compound has a distribution in a thickness direction of the hole injection layer .   The method for producing an organic electroluminescent element according to claim 1, wherein the surface treatment is a plasma treatment.   The method for producing an organic electroluminescent element according to claim 1, wherein the surface treatment is an ultraviolet irradiation treatment. The manufacturing method of the organic electroluminescent element in any one of Claim 1 to 3 with which a positive hole injection layer contains the compound which has an arylamine skeleton. The method for producing an organic electroluminescent element according to claim 1, wherein the portion containing the electron-accepting compound is in contact with at least the anode of the hole injection layer. The average thickness of the portion containing the electron-accepting compound is 20 nm or less.
The manufacturing method of the organic electroluminescent element in any one of them. It is manufactured by the method for manufacturing an organic electroluminescent element according to claim 1.
An organic electroluminescent element characterized by the above. The layer which absorbs the electromagnetic wave of the wavelength irradiated by the electromagnetic wave irradiation process on the light emission surface is further provided.
The organic electroluminescent element of description.