JP2012134070A - Organic electroluminescent element and method of manufacturing the same, and organic electroluminescent display device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic electroluminescent element and an organic electroluminescent display device, in which luminance unevenness is corrected in-situ for a part where the luminance unevenness is actually in generation with a low cost and without losing power efficiency of the organic electroluminescent element.SOLUTION: The method of manufacturing the organic electroluminescent element includes a correction process of the luminance unevenness in which the luminance unevenness is corrected by irradiating with electromagnetic waves the part in the light-emitting surface of the organic electroluminescent element where the luminance unevenness is in generation. The method of manufacturing the organic electroluminescent display device includes: a manufacturing process of the organic electroluminescent display device in which the organic electroluminescent display device formed by arranging a plurality of organic electroluminescent elements is manufactured; and the correction process of the luminance unevenness in which the luminance unevenness in the light-emitting surface is corrected by irradiating with the electromagnetic waves the part in the light-emitting surface of the organic electroluminescent display device.

Description

  The present invention relates to an organic electroluminescent element and a manufacturing method thereof, and an organic electroluminescent display device and a manufacturing method thereof.

  Organic electroluminescent elements are expected as next-generation displays, lighting devices, backlights and the like because they can emit surface light. However, since the organic electroluminescent element is a current device, it is necessary to pass a large current. Especially, when the light emitting surface of the element is made large, the voltage applied in the light emitting surface is uneven due to the wiring resistance. As a result, there is a problem that the current flowing in the light emitting surface changes to cause large luminance unevenness.

  In an organic electroluminescent device having a large light emitting area, a transparent electrode such as indium tin oxide (ITO) is usually used as an anode. When applying a voltage between the electrodes, since ITO has a high resistivity, the voltage drops as the distance from the anode feeding portion increases. As a result, the voltage applied to the organic layer decreases as the distance from the anode power feeding portion increases, and as a result, luminance unevenness occurs such that the luminance is high in the vicinity of the anode power feeding portion and the luminance is low in the distance from the anode power feeding portion.

In order to solve the problem of uneven brightness, for example, in order to suppress a voltage drop due to wiring resistance, a method of installing a highly conductive metal wiring in a mesh shape, a lower resistivity than ITO on the outer peripheral portion of the light emitting surface A method of forming an auxiliary electrode with a metal having a metal is known (see, for example, Patent Document 1).
However, the larger the panel, the greater the influence of the voltage drop of ITO from the outer periphery, and it was difficult to sufficiently suppress the in-plane luminance unevenness. In addition, the installation of a large number of auxiliary wirings for correcting luminance unevenness has greatly increased the cost and has been a major obstacle to commercializing large-area organic electroluminescent devices.

  As another method, for example, a method of improving luminance unevenness by changing the thickness of the organic layer within the light emitting surface has been proposed (see Patent Document 2). In this proposal, luminance unevenness is compensated for by reducing the thickness of the organic layer in the portion where the influence of the voltage drop of the electrode is large. However, when the thickness of the organic layer is distributed as described above, there is a problem that chromaticity unevenness occurs due to light interference. In addition, this proposal has a problem that it is not easy to change the film thickness within the light emitting surface with good reproducibility, and it cannot cope with the manufacturing process and unexpected luminance unevenness generated after the manufacturing.

  Further, a method for compensating for in-plane luminance unevenness due to a voltage drop in the electrode caused by the distance from the electrode power supply unit by changing the carrier injection efficiency or the resistance of the charge transport layer in the surface has been proposed. (See Patent Document 3). However, when the carrier injection efficiency is lowered or the resistance of the charge transport layer is lowered, there is a problem that the driving voltage increases and the power efficiency is lowered. Further, similarly to the above proposal, there is a problem that it is not possible to cope with unexpected luminance unevenness generated after the manufacturing process and after manufacturing.

  On the other hand, in a display device such as a display in which an organic electroluminescent element is used as a pixel and the light emitting surface is arranged, current flowing in the organic electroluminescent element portion is generated for each pixel due to manufacturing irregularities of a thin film transistor (TFT) that drives the pixel. It is known that luminance unevenness in the light emitting surface is caused due to the difference.

In order to prevent this, attempts have been made to suppress unevenness by increasing the number of TFTs or changing the manufacturing method.
For example, it has been proposed to detect a change in luminance of the display unit, and to change the drive voltage or drive current of the anode in accordance with the change in luminance, thereby correcting the luminance of the display unit to be constant (Patent Document). 4).
However, in this proposal, it is necessary to install a device for detecting a change in luminance, a wiring and a device for changing a driving voltage or a driving current, and there is a problem that costs increase.

  Therefore, there is no need to install other wirings, devices, etc. in the organic electroluminescent element, or to produce the element by changing the thickness or resistance of the layers constituting the organic electroluminescent element in the plane, and the power of the element At present, an organic electroluminescent element and a method for manufacturing an organic electroluminescent display device that can correct luminance unevenness in a light emitting surface in-situ without reducing efficiency have not yet been obtained.

JP-A-10-214684 Japanese Patent Laid-Open No. 11-40362 JP 2006-222392 A JP-A-11-109918

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention is an organic electroluminescence that can correct luminance unevenness in-situ with respect to a portion where luminance unevenness actually occurs at low cost and without impairing the power efficiency of the organic electroluminescent element. An object is to provide an element, a manufacturing method thereof, an organic light emitting display device, and a manufacturing method thereof.

Means for solving the above problems are as follows. That is,
<1> A method for manufacturing an organic electroluminescent device, comprising a luminance unevenness correcting step of correcting the luminance unevenness by irradiating an electromagnetic wave to a portion where the luminance unevenness in the light emitting surface of the organic electroluminescent element is generated. .
<2> The method for producing an organic electroluminescent element according to <1>, further including a luminance unevenness detecting step of detecting a luminance unevenness by obtaining a luminance distribution in a light emitting surface of the organic electroluminescent element.
<3> The method for producing an organic electroluminescent element according to any one of <1> to <2>, wherein the electromagnetic wave irradiation is performed through an exposure mask that adjusts the transmittance of the electromagnetic wave.
<4> The method for producing an organic electroluminescent element according to any one of <1> to <2>, wherein the irradiation with the electromagnetic wave is performed by scanning the light emitting surface while changing the irradiation time of the electromagnetic wave.
<5> An organic electroluminescence device produced by the production method according to any one of <1> to <4>,
The element configuration in the light emitting surface is the same, and
When the current density is measured by applying the same voltage to any two fragments cut out from the light emitting surface, the difference in current density between the fragment (A) having a high current density and the fragment (B) having a low current density The organic electroluminescent element is characterized in that the ratio [(A−B) / A] is 10% or more.
<6> The organic electroluminescence device according to <5>, which includes a hole injection layer and includes an organic compound having an arylamine structure as a partial skeleton in the hole injection layer.
<7> The organic electroluminescence device according to any one of <5> to <6>, further including an anode and a cathode, wherein at least one of the anode and the cathode is a metal oxide electrode.
<8> The organic electroluminescent element according to any one of <5> to <7>, wherein the visible light transmittance is 20% or more.
<9> The organic electroluminescence device according to any one of <5> to <8>, which has flexibility.
<10> The organic electroluminescence device according to <5> to <9>, further including an electromagnetic wave absorbing layer that absorbs an electromagnetic wave having a wavelength used in electromagnetic wave irradiation on a light emitting surface.

<11> An organic electroluminescent display device manufacturing step of manufacturing an organic electroluminescent display device in which a plurality of organic electroluminescent elements are arranged;
A method of manufacturing an organic light emitting display device, comprising: a luminance unevenness correcting step of correcting the luminance unevenness in the light emitting surface by irradiating an electromagnetic wave to a portion where the luminance unevenness in the light emitting surface of the organic light emitting display device is generated. .
<12> The method for producing an organic electroluminescent display device according to <11>, further including a luminance unevenness detection step of obtaining a luminance distribution in a light emitting surface of the organic electroluminescent device to detect luminance unevenness.
<13> The method for producing an organic electroluminescence display device according to any one of <11> to <12>, wherein the irradiation with the electromagnetic wave is performed through an exposure mask that adjusts the transmittance of the electromagnetic wave.
<14> The method for producing an organic electroluminescent display device according to any one of <11> to <12>, wherein the irradiation with the electromagnetic wave is performed by scanning the light emitting surface while changing the irradiation time of the electromagnetic wave.
<15> An organic electroluminescence display device manufactured by the manufacturing method according to any one of <11> to <14>,
The element configurations of the organic electroluminescent elements of the same emission color in the light emitting surface are the same, and
When the current density is measured by applying the same voltage to any two organic electroluminescent elements of the same emission color cut out from the light emitting surface, the element (A) having a high current density and the element (B having a low current density) ) And the current density difference ratio [(A−B) / A] is 10% or more.
<16> The organic electroluminescent display device according to <15>, wherein the organic electroluminescent element includes a hole injection layer, and the hole injection layer includes an organic compound having an arylamine structure as a partial skeleton.
<17> The organic electroluminescence device according to any one of <15> to <16>, wherein the organic electroluminescence device has an anode and a cathode, and at least one of the anode and the cathode is a metal oxide electrode. It is a display device.
<18> The organic electroluminescence display device according to any one of <15> to <17>, wherein the visible light transmittance is 20% or more.
<19> The organic electroluminescence display device according to any one of <15> to <18>, which has flexibility.
<20> The organic electroluminescence display device according to <15> to <19>, further including an electromagnetic wave absorbing layer that absorbs an electromagnetic wave having a wavelength used in electromagnetic wave irradiation on a light emitting surface.

  According to the present invention, it is possible to solve the above-mentioned problems in the past, achieve the above-mentioned object, at a low cost, and without damaging the power efficiency of the element, with respect to the portion where the luminance unevenness actually occurs, It is possible to provide an organic electroluminescent element capable of correcting luminance unevenness in-situ and a manufacturing method thereof, an organic electroluminescent display device and a manufacturing method thereof.

FIG. 1 is a graph showing the in-plane luminance distribution of the organic electroluminescent element before luminance unevenness correction in Example 1. FIG. 2 is a graph showing the in-plane luminance distribution of the organic electroluminescent element after luminance unevenness correction in Example 1. FIG. 3 is a graph showing the voltage-current density characteristics of 5 mm square samples A and B obtained from the organic electroluminescent element after luminance unevenness correction in Example 1. FIG. 4 is a graph showing voltage-current density characteristics of 5 mm square samples C and D obtained from the organic electroluminescence element after luminance unevenness correction in Comparative Example 1.

(Method for manufacturing organic electroluminescent element and method for manufacturing organic electroluminescent display device)
The method for producing an organic electroluminescent device of the present invention includes a luminance unevenness correcting step of correcting the luminance unevenness by irradiating electromagnetic waves to at least a portion where the luminance unevenness in the light emitting surface of the organic electroluminescent device is generated, and further necessary. Depending on, other steps are included.
The organic electroluminescent display device manufacturing method of the present invention includes at least an organic electroluminescent display device manufacturing process for manufacturing an organic electroluminescent display device in which a plurality of organic electroluminescent elements are arranged, and a light emitting surface of the organic electroluminescent display device. A luminance unevenness correcting step of correcting the luminance unevenness by irradiating electromagnetic waves to a portion where the luminance unevenness is generated, and further including other steps as necessary.

<Luminance unevenness correction process>
The brightness unevenness correcting step is a step of correcting the brightness unevenness by irradiating an electromagnetic wave to a portion where the brightness unevenness occurs in the light emitting surface of the organic electroluminescent element or the organic light emitting display device.
Here, the portion where the luminance unevenness is generated refers to a portion where the luminance varies within the light emitting surface of one element in the organic electroluminescence device, and the difference in luminance occurs. In the electroluminescent display device, in addition to the portion where the luminance varies within the light emitting surface of one organic electroluminescent element (pixel), the luminance is increased between the elements of the same luminescent color arranged in the organic electroluminescent display device. Includes parts with variations.

It is essential to use electromagnetic wave irradiation as a method for correcting luminance unevenness according to the present invention. In the portion where the electromagnetic wave is irradiated on the light emitting surface of the organic light emitting device or the organic light emitting display device, the driving voltage increases and the luminance decreases. Therefore, the high luminance portion is irradiated with the electromagnetic wave, and the low luminance portion is irradiated. The organic electroluminescence device or the organic electroluminescence display device having a light emitting surface with a uniform light amount distribution can be corrected by adjusting the irradiation amount of the electromagnetic wave so that the electromagnetic wave is not irradiated Is obtained.
According to such a luminance unevenness correction method, it is not necessary to provide auxiliary wiring, a drive circuit, a device for correcting luminance unevenness, and the like, so that the cost can be reduced.

The electromagnetic wave used in the present invention has a vacuum wavelength in the range of about 10 ⁻¹⁷ m 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.
As a light source of the electromagnetic wave irradiation apparatus, for example, a high pressure mercury lamp, a low pressure mercury lamp, a hydrogen (deuterium) lamp, a rare gas (for example, xenon, argon, helium, neon) discharge lamp, a nitrogen laser, an excimer laser (for example, , XeCl, XeF, KrF, KrCl, etc.), hydrogen laser, halogen laser, harmonics of various visible-infrared lasers, and the like.
These may be used individually by 1 type and may use 2 or more types together.

  The electromagnetic wave irradiation device is not particularly limited as long as light can be emitted from the various light sources, and commercially available products can be used. Examples of the commercially available product include an amber tester (light source: xenon lamp, manufactured by Shinto Kagaku Co., Ltd.), a blue-violet semiconductor laser KLX-120 mW type (emission peak: 405 nm, manufactured by Kikko Giken Co., Ltd.), and the like.

  The irradiation amount of the electromagnetic wave is relatively determined by the size of luminance variation (brightness level difference) and cannot be uniquely determined, but it is preferable to set a larger amount of irradiation as the luminance is higher. . That is, the luminance reduction width of the portion with high luminance is relatively increased and the luminance reduction of the portion with low luminance is suppressed, so that the luminance distribution is made uniform while maintaining the light amount of the entire light emitting surface. be able to.

  The method for irradiating the electromagnetic wave according to the luminance unevenness on the light emitting surface of the organic electroluminescent element is not particularly limited and can be appropriately selected according to the purpose, but the electromagnetic wave irradiation adjusts the transmittance of the electromagnetic wave. It is preferable that the irradiation is performed through an exposure mask, or the irradiation of electromagnetic waves is performed by scanning the light emitting surface while changing the irradiation amount of the electromagnetic waves. Examples of the scanning method include a method in which a laser that irradiates an electromagnetic wave is installed on an automatically controlled xy stage (ALD-220-C2P, manufactured by Chuo Seiki Co., Ltd.), and the laser is moved in the xy direction. .

  Examples of the method of changing the irradiation amount of the electromagnetic wave include a method of changing the irradiation time and a method of changing the irradiation intensity. It is preferable to increase the irradiation time or increase the irradiation intensity for a portion with high luminance, and shorten the irradiation time or decrease the irradiation intensity for a portion with low luminance.

<Luminance unevenness detection process>
The organic electroluminescent device manufacturing method and the organic electroluminescent display device manufacturing method of the present invention determine the luminance distribution in the light emitting surface of the organic electroluminescent device in order to determine the electromagnetic wave irradiation intensity in the luminance unevenness correcting step. It is preferable to further include a luminance unevenness detecting step for detecting unevenness.
There is no restriction | limiting in particular as the measuring method of the said brightness | luminance, For example, it can measure by Konica Minolta CS-1000 etc. Thus, by measuring the luminance while scanning the entire light emitting surface, the luminance distribution in the entire light emitting surface can be obtained.

  As a method for setting the electromagnetic wave irradiation amount from the luminance distribution obtained by the luminance unevenness detection method, for example, the luminance distribution is converted into a black and white tone, and the correction mask is produced based on the black and white image. A method is mentioned. The correction mask is preferably one that adjusts the transmittance of the electromagnetic wave to be irradiated in the plane, and the gradation expression may be prepared with an area gradation or a gradation gradation. . As a method of changing the amount of electromagnetic wave irradiation in the plane to correct brightness unevenness, using an area gradation mask has the advantage that brightness unevenness can be corrected with good reproducibility. On the other hand, there is a disadvantage that uneven brightness tends to occur. In addition, when using a mask with gray scales, it is necessary to fabricate a mask with complex shading according to the characteristics of the element, and there is a drawback that mask fabrication becomes complicated, but the element is allowed to emit light for a long time. In this case, there is an advantage that uneven brightness can be prevented. Therefore, it is preferable to use these properly depending on the application.

Below, the element structure of the organic electroluminescent element by this invention is demonstrated.
The organic electroluminescent element usually 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 further, if necessary, a hole transport layer. , Other functional components such as an electron transport layer, a hole block layer, an electron block layer, and an electron injection layer, and other components such as a substrate and a protective layer.

  The organic electroluminescent element usually 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.

  The 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 or a sputtering method, a wet coating method, a transfer method, a printing method, an ink jet method, or the like. Can be formed.

The properties of the organic electroluminescent element as a whole are not particularly limited and may be appropriately selected depending on the purpose, and may be transparent (including translucent) or opaque, and when transparent, may be colorless and transparent or colored and transparent. Good. Moreover, you may have flexibility according to the intended purpose.
When the element is transparent, the visible light transmittance is at least 20%, preferably 40% or more, and more preferably 60% or more. Moreover, in the transparent organic electric field element, since both the anode and the cathode are made light transmissive, the wiring resistance of the electrode tends to increase, and the effect of the present invention is great.
In addition, in an organic electric field element having flexibility, it is necessary to use zinc indium oxide (IZO) which is difficult to break as an electrode, or to reduce the thickness of the electrode, which tends to increase the wiring resistance, and the effect of the present invention. Is big.

<< 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.
Examples of the material constituting the electrode include metals, alloys, metal oxides, conductive compounds, and mixtures thereof.

-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 with ITO. 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.

-Cathode-
There is no restriction | limiting in particular as a material which comprises the said cathode, According to the objective, it can select suitably, For example, an alkali metal (for example, Li, Na, K, Cs etc.), an alkaline earth metal (for example, Mg, Ca) Etc.), gold, silver, lead, aluminum, sodium-potassium alloy, lithium-aluminum alloy, magnesium-silver alloy, rare earth metals such as indium and ytterbium. These may be used singly or in combination of two or more 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- An aluminum alloy).

  There is no restriction | limiting in particular about the formation method of the said cathode, According to a well-known method, it can carry out and the method similar to the formation method of the above-mentioned anode can be used.

  In addition, when patterning is performed when forming the anode and the cathode, the patterning 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.

The electrode may be subjected to a surface treatment using oxygen, nitrogen, a rare gas, or the like.
The surface treatment is not particularly limited and may be appropriately selected according to the purpose. For example, known surface treatment methods such as various kinds of sputtering such as plasma treatment and ion beam sputtering, ultraviolet irradiation treatment, and radical beam treatment may be used. Can be mentioned. Among these, plasma processing is preferable in that it can be processed in a short time and can be performed in various gas atmospheres.

  As the plasma treatment, the apparatus and conditions can be appropriately selected as long as the gas can be turned into plasma and the substrate surface can be treated. 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.

<< 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 amount used is within the preferred 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.

<< 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 luminescent dopant in the luminescent layer is preferably 0.1% by mass to 50% by mass with respect to the total mass of the compound generally forming the luminescent layer in the luminescent layer. 1 mass%-50 mass% are more preferable from a viewpoint of efficiency, and 2 mass%-40 mass% are especially preferable.

--Phosphorescent material--
There is no restriction | limiting in particular as said phosphorescence-emitting material, According to the objective, it can select suitably, The complex etc. which contain a transition metal atom or a lanthanoid atom 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. The host material may be one type or two or more types.
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 transporting 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, and the like. 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.

<Other ingredients>
The organic electroluminescent device of the present invention is selected as the other components according to the purpose, hole transport layer, hole transport intermediate layer (electron block layer), electron transport intermediate layer (hole block layer) Each functional layer such as an electron transport layer and an electron injection layer, a substrate, a protective layer, and the like may be further included.

<< 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 contained include those similar to 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 injection layer and the electron transport layer is not particularly limited as long as it has an electron donating property and has a property of reducing an organic compound, and can be appropriately selected according to the purpose. However, an alkali metal such as Li, an alkaline earth metal such as Mg, a transition metal containing a rare earth metal, a reducing organic compound, or the like is preferable. As the metal, a metal having a work function of 4.2 eV or less is particularly preferable. Specifically, Li, Na, K, Be, Mg, Ca, Sr, Ba, Y, Cs, La, Sm, Gd, Yb Etc. 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 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. .

<< 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 average 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 made of one or more of the materials described above, or may have a multilayer structure made up of a plurality of layers having the same composition or different compositions. Good.

<< 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.
There is no restriction | limiting in particular as a material of the said board | substrate, According to the objective, it can select suitably, For example, inorganic materials, such as a yttria stabilized zirconia (YSZ) and glass (an alkali free glass, soda-lime glass, etc.); Polyethylene Examples thereof include polyesters such as terephthalate, 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 organic electroluminescent element may be entirely 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 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.

(Organic electroluminescent device and organic electroluminescent display 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 electroluminescent display device of the present invention is manufactured by the method for manufacturing the organic electroluminescent display device of the present invention.

  As described above, the organic electroluminescent element includes an electrode, a light emitting layer, and a hole injection layer, and each functional layer including these includes all the configurations described in the method for manufacturing the organic electroluminescent element of the present invention. Can be applied.

  The organic electroluminescent device manufactured by the above manufacturing method has the following characteristics. That is, the element configuration in the light emitting surface is the same, and any two parts in the light emitting surface are selected, and the same voltage is applied between the anode and the cathode of the fragment divided by the plane perpendicular to the light emitting surface. In this case, the ratio [(A−B) / A] of the difference in current density between the fragment (A) having a high current density flowing through the fragment and the fragment (B) having a low current density is 10% or more. Including parts.

  The organic electroluminescent display device is formed by arranging a plurality of organic electroluminescent elements having the structure described in the method for manufacturing an organic electroluminescent element of the present invention. The arrangement direction and method are not particularly limited as long as the organic electroluminescent device forms a light emitting surface, and can be appropriately selected from known materials. The light emitting surface may be monochromatic or color. . Moreover, as the organic electroluminescent element, all of the above-described configurations can be applied.

  The organic electroluminescent display device manufactured by the above-described manufacturing method has the following characteristics. That is, when the element configurations of the organic electroluminescent elements having the same luminescent color in the light emitting surface are the same and two organic electroluminescent elements having the same luminescent color in the light emitting surface are arbitrarily selected, When the same voltage is applied between the anode and the cathode of the organic electroluminescent element divided by a flat plane, an element (A) having a high current density flowing through the organic electroluminescent element and an element having a low current density (B The organic electroluminescent element having a current density difference ratio [(AB) / A] of 10% or more in the light emitting surface.

The organic electroluminescent element and the organic electroluminescent display device may have an electromagnetic wave absorbing layer that absorbs an electromagnetic wave having a wavelength irradiated in the luminance unevenness correcting step on the light emitting surface.
The organic electroluminescent device exposed in the luminance unevenness correction process is sensitive to the wavelength of the irradiated electromagnetic wave, and thus the light emitting surface of the organic electroluminescent device was exposed to light including a specific wavelength from the outside. In some cases, the luminance may decrease. Therefore, in order to prevent unintended exposure, it is preferable to provide an electromagnetic wave absorbing layer that absorbs electromagnetic waves having a wavelength irradiated in the luminance unevenness correction process on the light emitting surface of the organic electroluminescence element after performing the luminance unevenness correction.

There is no restriction | limiting in particular as said electromagnetic wave absorption layer, According to the wavelength to absorb, it can select suitably, For example, a filter, a film, etc. are mentioned.
The method for installing the electromagnetic wave absorbing layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the organic electroluminescent element or the entire organic electroluminescent display device may be wrapped, or the light emission thereof. It may be covered so as to cover the surface.

  EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example at all.

Example 1
<Manufacture of organic electroluminescence device>
A glass substrate with ITO having a thickness of 100 nm (substrate thickness: 0.7 mm, Super Flat ITO manufactured by Geomatek Co., Ltd.) was washed and dried sufficiently, and then the ITO surface was removed using an EXAM type plasma cleaning device manufactured by Shinko Seiki Co., Ltd. Oxygen plasma treatment was performed. Next, the substrate was put into a vacuum vapor deposition apparatus (CM470 manufactured by Tokki Co., Ltd.), and 2-TNATA was vapor deposited so as to have a thickness of 120 nm. Next, NPD was deposited so as to have a thickness of 4 nm. Subsequently, HTL-1 was vapor-deposited so that thickness might be set to 3 nm. Next, mCP was vapor deposited so as to have a thickness of 3 nm. Next, mCP doped with 40% by mass PT-1 was deposited as the light emitting layer so that the thickness was 30 nm. Further, BCP was vapor-deposited so that the thickness was 39 nm and Balq was 39 nm. The vapor deposition rate was 0.2 nm / s. Next, LiF was vapor-deposited to a thickness of 1 nm, and finally aluminum (Al) was vapor-deposited to a thickness of 100 nm as a cathode. The deposition rate of LiF was 0.02 nm / s, and the deposition rate of Al was 1 nm / s. Next, sealing glass was adhere | attached using UV hardening adhesive (XNR5516Z by Nagase ChemteX Corporation), and the white organic electroluminescent element whose light emission area is 15 cm x 15 cm was obtained. The structure of the finally obtained element was mCP doped with ITO (100 nm) / 2-TNATA (120 nm) / NPD (4 nm) / HTL-1 (3 nm) / mCP (3 nm) / 40 mass% PT-1. (30 nm) / BAlq (39 nm) / BCP (1 nm) / LiF (1 nm) / Al (100 nm). In addition, the inside of a parenthesis represents average thickness.
Of the device components, 2-TNATA, NPD, HTL-1, mCP, PT-1, BAlq, and BCP are each represented by the following structural formula.

<Luminance unevenness detection>
A voltage of 7 V was applied to the obtained white organic electroluminescent element using a source measure unit SMU-1 manufactured by Keithley Instruments Inc., and the luminance distribution in the light emitting surface of 15 cm × 15 cm was determined by Konica Minolta. Measurements were made at 5 mm intervals using CS-1000. The results are shown in FIG. Brightness unevenness due to the wiring resistance of ITO was observed in the part far from the power supply connection part, and the ratio (maximum brightness / minimum brightness) between the maximum brightness and the minimum brightness in the light emitting surface was about 3.5 (Table 1).

<Electromagnetic wave irradiation for luminance unevenness correction>
The detected luminance unevenness was processed into a black and white image using Adobe Photoshop, and an image with darker black as the luminance was lower. An image was printed on a PET film with a gravure printing machine (GP-10 manufactured by Kurashiki Boseki Co., Ltd. (Kurabo)) to produce an exposure mask for correcting luminance unevenness. This mask was affixed on the light-emitting surface of the produced 15 cm square white organic electroluminescence device, and placed in an amber tester (light source: xenon lamp) manufactured by Shinto Kagaku Co., Ltd., and irradiated with electromagnetic waves for 2 hours. In the portion irradiated with electromagnetic waves through the mask, the voltage of the element was increased, the amount of flowing current was reduced, and the luminance was partially reduced. The in-plane luminance unevenness after electromagnetic wave irradiation was measured as described above. The results are shown in FIG.
The ratio of the maximum luminance to the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface after the electromagnetic wave irradiation was 1.3, and the luminance unevenness was corrected (see Table 1).

<Measurement of current density>
The white organic electroluminescent element of 15 cm square after luminance unevenness correction was put in a glove box (MDB Corporation, MDB-2B), and the sealing glass was removed. The sample A (5 mm × 5 mm) at the position closest to the power connection portion on the light emitting surface and the sample B (5 mm × 5 mm) at the position farthest from the power connection portion were cut together with the glass substrate. Although the sample A and B have the same element configuration, sample A is irradiated with electromagnetic waves for 2 hours, while sample B is cut by the exposure mask, so Not irradiated.
A part of the lower ITO electrode of the separated element was exposed and connected to the power source, and the already exposed Al cathode and the power source wiring were connected using a gold wire and a gold paste. The voltage-current density characteristics of Sample A and Sample B are shown in FIG. As apparent from FIG. 3, the driving voltage of sample A is increased by light irradiation, and the current hardly flows even though the device configuration is exactly the same as that of sample B. The current density in the case of applying a voltage of 7V is the sample A was 2.3 mA / cm ^2, it was 15.3mA / cm ² in the sample B. It can be seen that the current density flowing when the same voltage is applied is reduced by 85% due to the electromagnetic wave irradiation (the rate of decrease when the non-electromagnetic wave irradiation is 100%).

(Comparative Example 1)
A 15 cm square white organic electroluminescent element was produced in the same manner as in Example 1, and the luminance unevenness was measured. The results are shown in Table 1.
The element was put in a glove box without performing electromagnetic wave irradiation for correcting luminance unevenness, and the sealing glass was removed. The sample C (5 mm × 5 mm) at the position closest to the power connection portion on the light emitting surface and the sample D (5 mm × 5 mm) at the position farthest from the power connection portion were cut out together with the glass substrate. Samples C and D have the same element configuration and are not irradiated with electromagnetic waves. A part of the lower ITO electrode of the separated element was exposed and connected to the power source, and the already exposed Al cathode and the power source wiring were connected using a gold wire and a gold paste. The voltage-current density characteristics of Samples C and D are shown in FIG. As is clear from FIG. 4, Samples C and D showed almost the same voltage-current characteristics, and there was no significant difference in the current density when the same voltage was applied (as the rate of decrease in current density). Was less than 10%).

(Example 2)
A white organic electroluminescent element was produced in the same manner as in Example 1. Further, the luminance unevenness was detected in the same manner as in Example 1 except that the measurement point was changed from 5 mm to 1 mm. The results are shown in Table 1.

<Electromagnetic wave irradiation for luminance unevenness correction>
The position of the obtained element in the light emitting surface was taken as the xy coordinates, the brightness was taken as the z value, and the brightness unevenness was digitized. A semiconductor laser having a light emission peak at 405 nm (manufactured by Kikko Giken Co., Ltd., blue-violet semiconductor laser KLX-120 mW type) was installed on an automatically controlled xy stage (ALD-220-C2P, manufactured by Chuo Seiki Co., Ltd.). While moving the laser in the xy direction, the organic electroluminescence device was irradiated with laser (electromagnetic wave) to correct in-plane luminance unevenness. The electromagnetic wave irradiation time was controlled so as to become longer as the xy coordinate having a larger luminance z. In the portion irradiated with the electromagnetic wave, the voltage of the element increased, the amount of current flowing decreased, and the luminance decreased. When the in-plane luminance unevenness after the electromagnetic wave irradiation was measured, the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface was 1.3, and the luminance unevenness could be corrected.

Example 3
<Production of organic electroluminescence device>
A 100 nm thick glass substrate with ITO (substrate thickness 0.7 mm) was washed and sufficiently dried, and then the ITO surface was subjected to oxygen plasma treatment. Next, the substrate was put into a vacuum deposition apparatus, and 2-TNATA was deposited so as to have a thickness of 120 nm. Next, α-NPD was deposited so as to have a thickness of 4 nm. Subsequently, HTL-1 was vapor-deposited so that thickness might be set to 3 nm. Next, mCP was vapor deposited so as to have a thickness of 3 nm. Next, mCP doped with 40% by mass of PT-1 was deposited as a light emitting layer so as to have a thickness of 30 nm. Further, BCP was vapor-deposited so that the thickness was 39 nm and Balq was 39 nm. The vapor deposition rate was 0.2 nm / s. Next, LiF was vapor-deposited to a thickness of 1 nm, aluminum (Al) was vapor-deposited to a thickness of 0.5 nm, and Ag was vapor-deposited to a thickness of 20 nm. The deposition rate of LiF was 0.02 nm / s, and the deposition rates of Al and Ag were 0.5 nm / s. Next, the sealing glass was bonded using a UV curable adhesive to obtain a white organic electroluminescent element having a light emitting area of 15 cm × 15 cm.

<Luminance unevenness detection>
In Example 1, the luminance distribution was measured in the same manner as in Example 1 except that the applied voltage was changed from 7V to 8V. As a result, as in Example 1, the luminance unevenness due to the ITO wiring resistance is observed in the portion far from the power source connection portion, and the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface is 4.3 (see Table 1). It is considered that luminance unevenness occurred more than the element of Example 1 by reducing the metal film thickness in order to make the cathode transparent.

<Electromagnetic wave irradiation for luminance unevenness correction>
In Example 1, the electromagnetic wave was irradiated in the same manner as in Example 1 except that the electromagnetic wave irradiation time was changed from 2 hours to 2.6 hours.
In the portion irradiated with the electromagnetic wave, the voltage of the element increased, the amount of current flowing decreased, and the luminance decreased. When the in-plane luminance distribution after the irradiation was measured, the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface was 1.3, and the luminance unevenness could be corrected (see Table 1).

Example 4
<Production of organic electroluminescence device>
In Example 1, an organic electroluminescent element was produced in the same manner as in Example 1 except that the substrate was changed from a glass substrate with ITO to a film substrate with IZO (substrate: PET, thickness 0.1 mm), and the light emitting area was A 15 cm × 15 cm flexible white translucent organic electroluminescent element was obtained.

<Luminance unevenness detection>
In Example 1, the luminance distribution was measured in the same manner as in Example 1 except that the applied voltage was changed from 7V to 9V. As a result, as in Example 1, luminance unevenness due to the wiring resistance of IZO is observed in the portion far from the power supply connection portion, and the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface is 5.1 (see Table 1). It seems that luminance unevenness occurred more than the element of Example 1 because IZO having low conductivity was used for the electrode in order to provide flexibility.

<Electromagnetic wave irradiation for luminance unevenness correction>
In Example 1, the electromagnetic wave was irradiated in the same manner as in Example 1 except that the electromagnetic wave irradiation time was changed from 2 hours to 3.1 hours.
In the portion irradiated with the electromagnetic wave, the device voltage was increased, the amount of current flowing was reduced, and the luminance was lowered. When the in-plane luminance unevenness after the irradiation was measured, the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface was 1.3, and the luminance unevenness could be corrected (see Table 1).

  Table 1 below shows the characteristics of the elements, the form of electromagnetic wave irradiation, and the luminance unevenness in the light emitting surface in Examples 1 to 4 and Comparative Example 1.

(Example 5)
<Production of organic electroluminescence display device>
In Example 1, a monochrome display device was produced in the same manner as in Example 1 except that the ITO substrate and the cathode film formation were changed as follows.
A 100 nm thick glass substrate with ITO (substrate thickness 0.7 mm, substrate size 100 mm square) was patterned by wet etching to prepare a substrate in which 40 ITO electrodes having a width of 1 mm and a length of 80 mm were arranged in parallel. The distance between each electrode and the adjacent electrode was 0.5 mm.
Next, a cathode mask was prepared so that the cathode shape was 1 mm wide and 80 mm long. In the same manner as in Example 1, the mask was arranged on the substrate on which the organic film was deposited so that the cathode was formed in the direction perpendicular to the ITO electrode, and the cathode was produced in the same manner as in Example 1.
The obtained organic electroluminescence device was a simple matrix monochrome display device having a pixel size of 1 mm × 1 mm and a number of pixels of 40 × 40.

<Luminance unevenness detection>
The manufactured display device is passively driven at 30 frames / second, and the average luminance of the center pixel (flashing because it is passively driven, but including the time during which it is turned off) is 150 cd / m ^2. The brightness distribution in the display surface was measured in the same manner as in Example 1 except that the current value was set so that At this time, the maximum luminance / minimum luminance in the display surface was 2.3.

<Electromagnetic wave irradiation for luminance unevenness correction>
In Example 1, the electromagnetic wave was irradiated in the same manner as in Example 1 except that the electromagnetic wave irradiation time was changed from 2 hours to 1.1 hours. In the portion irradiated with the electromagnetic wave, the device voltage was increased, the amount of current flowing was reduced, and the luminance was lowered. When the in-plane luminance unevenness after irradiation was measured as described above, the ratio between the maximum luminance and the minimum luminance (maximum luminance / minimum luminance) in the light emitting surface was 1.3, and the uneven luminance was corrected (Table 2). reference).

<Subjective evaluation of uneven brightness>
The entire surface of the display screen of the organic electroluminescence display device thus obtained was made to emit light at 150 cd / m ² by the driving method described above, and 10 evaluators were subjected to sensory evaluation of luminance unevenness in the following five stages. The average value of each evaluation score was used as the evaluation score for luminance unevenness subjective evaluation.
〔Evaluation criteria〕
5: Very good 4: Good 3: Normal 2: Bad 1: Very bad

(Example 6)
In Example 5, except that the electromagnetic wave irradiation for correcting luminance unevenness was changed to the same electromagnetic wave irradiation method as in Example 2, a monochrome display device with corrected luminance unevenness was produced and evaluated in the same manner as in Example 5. went.

(Comparative Example 2)
In Example 5, a monochrome display device was produced and evaluated in the same manner as in Example 5 except that the luminance unevenness correction was not performed.

  Table 2 below shows the characteristics of the elements in Examples 5 and 6 and Comparative Example 2, the form of electromagnetic wave irradiation, luminance unevenness between elements, and evaluation of luminance unevenness.

The organic electroluminescent device and the organic electroluminescent display device of the present invention are not particularly limited and can be used for various known applications. However, the display device, display, backlight, electrophotography, illumination light source It can be suitably used for recording light sources, exposure light sources, reading light sources, signs, signboards, interiors, optical communications, and the like.
In the manufacturing method of the present invention, the luminance unevenness generated in the organic electroluminescent element and the organic light emitting display device that can be used as described above is produced at low cost and without actually degrading the power efficiency of the organic electroluminescent element. It is possible to correct the in-situ portion in-situ.

Claims (13)

  A method for manufacturing an organic electroluminescence device, comprising: a luminance unevenness correcting step of correcting the luminance unevenness by irradiating an electromagnetic wave to a portion where the luminance unevenness in the light emitting surface of the organic electroluminescence device is generated.   The manufacturing method of the organic electroluminescent element of Claim 1 which further includes the brightness | luminance nonuniformity detection process of calculating | requiring the luminance distribution in the light emission surface of an organic electroluminescent element, and detecting a brightness nonuniformity.   The method for producing an organic electroluminescent element according to claim 1, wherein the electromagnetic wave irradiation is performed through an exposure mask that adjusts the transmittance of the electromagnetic wave.   The method for producing an organic electroluminescent element according to claim 1, wherein the electromagnetic wave irradiation is performed by scanning the light emitting surface while changing the irradiation time of the electromagnetic wave. An organic electroluminescence device manufactured by the manufacturing method according to claim 1,
The element configuration in the light emitting surface is the same, and
When the current density is measured by applying the same voltage to any two fragments cut out from the light emitting surface, the difference in current density between the fragment (A) having a high current density and the fragment (B) having a low current density The organic electroluminescent element, wherein the ratio [(AB) / A] is 10% or more.   The organic electroluminescent element according to claim 5, comprising an organic compound having a hole injection layer and having an arylamine structure as a partial skeleton in the hole injection layer.   The organic electroluminescent element according to claim 5, further comprising an anode and a cathode, wherein at least one of the anode and the cathode is a metal oxide electrode.   The organic electroluminescence device according to any one of claims 5 to 7, which has a visible light transmittance of 20% or more.   The organic electroluminescent element according to claim 5, which has flexibility.   The organic electroluminescent element according to claim 5, further comprising an electromagnetic wave absorbing layer that absorbs an electromagnetic wave having a wavelength used in electromagnetic wave irradiation on a light emitting surface. An organic electroluminescent display device manufacturing process for manufacturing an organic electroluminescent display device in which a plurality of organic electroluminescent elements are arranged;
A method of manufacturing an organic light emitting display device, comprising: a luminance unevenness correcting step of correcting the luminance unevenness in the light emitting surface by irradiating an electromagnetic wave to a portion where the luminance unevenness in the light emitting surface of the organic light emitting display device is generated.   The method of manufacturing an organic electroluminescent display device according to claim 11, further comprising a luminance unevenness detecting step of detecting a luminance unevenness by obtaining a luminance distribution in a light emitting surface of the organic electroluminescent device. An organic light emitting display device manufactured by the manufacturing method according to claim 11,
The element configurations of the organic electroluminescent elements of the same emission color in the light emitting surface are the same, and
When the current density is measured by applying the same voltage to any two organic electroluminescent elements of the same emission color cut out from the light emitting surface, the element (A) having a high current density and the element (B having a low current density) The organic electroluminescence display device is characterized in that the ratio [(A−B) / A] of the difference in current density with respect to the current density is 10% or more.