JP2010257573A - Light emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting element which is superior in uniformity of brightness and efficiency in taking out light, with a wide selection band of optical wavelength which causes optical scattering. <P>SOLUTION: The light emitting element includes a light emitting part and a microstructure film. The microstructure film has a surface parallel to the light emitting surface of the light emitting element. A micropore in which an average aperture is 5-1,000 mm, an average pore density is 1×10<SP>6</SP>-10<SP>10</SP>/mm<SP>2</SP>, and a regulation degree defined by the following equation (i) is ≥50%, is formed on the surface parallel to the light emitting surface of the light emitting element: equation (i): regulation degree (%)=B/A×100. In this equation (i), A represents the total number of micropores within a measurement range, and B represents the number of centroids within such measurement range of a micropore as contains six centroids of micropores other than the micropore inside a circle when the circle is drawn having the centroid of the micropore as the center, having the shortest radius while inscribing to the edge of other micropore. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light-emitting element typified by an electroluminescence (EL) element, such as an LED element or an organic electroluminescence element.

  In a light-emitting element typified by an EL element such as an LED element or an organic EL element, a method of forming a diffraction grating inside the element as described in Patent Document 1, for example, in order to increase the light extraction efficiency Has been proposed. The guided light inside the element is diffracted by such a diffraction grating and extracted outside the element. As a result, the light extraction efficiency is improved as compared with the case where no diffraction grating is provided.

  When such a diffraction grating is formed inside a light emitting element, a fine concavo-convex pattern is formed inside the light emitting element by a photolithography process used for semiconductor microfabrication. When the pitch of the fine uneven pattern is about 1 μm or less, an expensive exposure apparatus and a complicated process are required, and there is a problem that the manufacturing cost becomes very high.

  In Patent Document 2, etc., a light diffusion layer in which fine particles having a refractive index different from that of a matrix is dispersed in a transparent matrix inside the light emitting element, and the light extraction efficiency is suppressed by suppressing the guided light inside the element. Techniques to enhance have been proposed. The light emitted from the light emitting part is scattered by fine particles randomly arranged in the matrix, and the guided light inside the device is suppressed. At this time, the brightness does not vary in the direction of the light emitting surface. However, since the light emitted in the vertical direction of the substrate by the light emitting layer is scattered in various directions by the fine particles randomly arranged in the matrix, there arises a problem that the front luminance is remarkably lowered.

  In order to improve such problems, Patent Document 3 proposes a method for improving the light extraction efficiency by using a diffraction grating layer having irregularities as a light diffusion layer without reducing the uniformity of luminance. ing. However, although the light extraction efficiency is improved, improvement in uniformity within the device surface is desired, and in order to actually scatter various wavelengths only with the diffraction grating layer, the wavelength selection region is narrow. There was a problem.

Japanese Patent Laid-Open No. 11-283951 Japanese Patent Laid-Open No. 6-151061 JP 2006-190573 A

  Accordingly, an object of the present invention is to provide a light-emitting element that is more excellent in luminance uniformity, has good light extraction efficiency, and has a wide light wavelength selection region that causes light scattering.

As a result of intensive studies to achieve the above object, the present inventor uses a fine structure film having micropores satisfying a specific average pore diameter, average pore density, and degree of ordering as a diffraction grating portion or a light scattering layer. As a result, the above-mentioned problems have been solved. Furthermore, it has been found that the scattering of the wavelength region of light is expanded by mixing another material into the microstructure film.
That is, the present invention provides the following (1) to (10).

(1) A light-emitting element including a light-emitting portion and a fine structure film,
The fine structure film has a surface parallel to the light emitting surface of the light emitting element, and the surface parallel to the light emitting surface of the light emitting element has an average pore diameter of 5 to 1000 nm and an average pore density of 1 × 10 ^6. A light emitting device characterized in that micropores having a degree of ordering defined by the following formula (i) of 50% or more are formed at ˜1 × 10 ¹⁰ / mm ² .
Ordering degree (%) = B / A × 100 (i)
In the formula (i), A represents the total number of micropores in the measurement range. B is centered on the center of gravity of one micropore, and when a circle with the shortest radius inscribed in the edge of another micropore is drawn, the center of gravity of the micropore other than the one micropore is placed inside the circle. This represents the number in the measurement range of the one micropore to be included.

  (2) In the above (1), the light emitting portion is a light emitting portion of an electroluminescence (EL) element in which a light emitting layer that emits light when an electric field is applied is sandwiched between a first electrode and a second electrode. The light emitting element of description.

(3) The light emitting device further includes a substrate,
The light emitting element has a structure in which the fine structure film and the light emitting portion are provided in this order on the substrate, and a bottom emission type light emitting element in which one surface of the substrate forms a light emitting surface of the light emitting element. The light-emitting device according to (1) or (2) above.

(4) The light emitting device further includes a substrate,
The light emitting element has a structure in which the light emitting portion and the fine structure film are provided in this order on the substrate, and a bottom emission type light emitting element in which one surface of the substrate forms a light emitting surface of the light emitting element. The light-emitting device according to (1) or (2) above.

(5) The light emitting device further includes a substrate,
The light emitting element has a structure in which the light emitting portion and the fine structure film are provided in this order on the substrate, and a top emission type in which one surface of the fine structure forms a light emitting surface of the light emitting element. The light emitting device according to (1) or (2), which is a light emitting device.

(6) The light emitting device further includes a substrate,
The light emitting element has a structure in which the microstructure film and the light emitting part are provided in this order on the substrate, and a top emission type light emitting device in which one surface of the light emitting part forms a light emitting surface of the light emitting element. The light emitting element according to (1) or (2), which is an element.

  (7) The light emitting device according to any one of (1) to (6) above, wherein the thickness of the microstructure film is in a range of 0.05 μm to 150 μm.

  (8) The light emitting device according to any one of (1) to (7), wherein the microstructure film is an aluminum anodic oxide film having micropores.

  (9) The light emitting device according to any one of (1) to (8), which is an organic EL device.

  (10) The light emitting device according to any one of (1) to (8), which is an LED device.

  As will be described below, according to the present invention, it is possible to provide a light-emitting element that is more excellent in luminance uniformity, has better light extraction efficiency, and has a wider light wavelength selection region that causes light scattering.

FIG. 1 is a schematic view showing an example of a preferred embodiment of the light emitting device of the present invention. FIG. 2 is an explanatory diagram of a method for calculating the degree of ordering of micropores. FIG. 3 is a schematic end view of an aluminum substrate and an anodized film formed on the aluminum substrate. FIG. 4 is a partial cross-sectional view of aluminum anodization, which is a preferred example of the microstructure film in the present invention. FIG. 5 is a surface photograph (magnification of 10,000 times) of the aluminum anodic oxide film after dissolving and removing the aluminum substrate in Example 1.

Hereinafter, the light emitting device of the present invention will be described in detail.
The light emitting device of the present invention is a light emitting device comprising a light emitting part and a fine structure film,
The fine structure film has a surface parallel to the light emitting surface of the light emitting element, and the surface parallel to the light emitting surface of the light emitting element has an average pore diameter of 5 to 1000 nm and an average pore density of 1 × 10 ^6. It is characterized in that micropores having a degree of ordering defined by the following formula (i) of 50% or more are formed at ˜1 × 10 ¹⁰ pieces / mm ² .
Ordering degree (%) = B / A × 100 (i)
In the formula (i), A represents the total number of micropores in the measurement range. B is centered on the center of gravity of one micropore, and when a circle with the shortest radius inscribed in the edge of another micropore is drawn, the center of gravity of the micropore other than the one micropore is placed inside the circle. This represents the number in the measurement range of the one micropore to be included.

  FIG. 1 is a schematic view showing an example of a preferred embodiment of the light emitting device of the present invention, and the light emitting device 10 is shown as an EL device. Note that the EL element referred to here includes a wide range of light emitting elements that emit light when an electric field is applied. In addition to intrinsic EL elements such as organic EL elements and inorganic EL elements, injection type EL elements such as LED elements are used. Including.

  As shown in FIG. 1, in a light emitting device 10 according to an embodiment of the present invention, a substrate 1, a fine structure film 2, and a light emitting unit 7 are provided in this order. The light-emitting portion 7 in FIG. 1 has a typical structure of a light-emitting portion of an EL element in which a light-emitting layer 5 that emits light when an electric field is applied is sandwiched between a first electrode 4 and a second electrode 6. is there.

When the light emitting element 10 shown in FIG. 1 is a bottom emission type light emitting element, the fine structure film 2 functions as a transmission type diffraction grating part or a transmission type light scattering layer, and light emitted from the light emitting layer 5. Are emitted to the outside through the fine structure film 2 and the substrate 1. Therefore, the surface 1a of the upper substrate 1 in the drawing is a light emitting surface.
Here, since the fine structure 2 functions as a transmissive diffraction grating portion or a transmissive light scattering layer, the micropore 3 is formed on the surface 2a parallel to the light emitting surface 1a. In FIG. 1, the opening of the micropore 3 faces the substrate 1. However, the opening of the micropore 3 may face the first electrode 4.

On the other hand, when the light emitting element 10 shown in FIG. 1 is a top emission type light emitting element, the fine structure film 2 functions as a reflection type diffraction grating part or a reflection type light scattering layer and is emitted from the light emitting layer 5. The reflected light passes through the light emitting unit 7 after being reflected by the fine structure film 2 and is emitted to the outside. Therefore, the surface 6a of the second electrode 6 on the lower side in the figure becomes the light emitting surface.
Since the fine structure 2 functions as a reflective diffraction grating portion or a reflective light scattering layer, the micropore 3 is formed on the surface 2a parallel to the light emitting surface 6a. In FIG. 1, the opening of the micropore 3 faces the substrate 1. However, when the micropore 3 functions as a reflective diffraction grating portion or a reflective light scattering layer, the opening of the micropore 3 is It may be configured to face one electrode 4, but is rather preferable.

  Accordingly, the light-emitting element 10 shown in FIG. 1 transmits the light emitted from the light-emitting layer 5 or transmits the light emitted from the light-emitting layer 5. It can be configured as either a bottom emission type light emitting element or a top emission type light emitting element depending on whether it is reflected.

  The light-emitting element 10 shown in FIG. 1 has a structure in which the fine structure film 2 and the light-emitting portion 7 are sequentially stacked on the substrate 1, but is not limited thereto, and other than the substrate 1, the fine-structure film 2 and the light-emitting portion 7. A component may be included. Specific examples of such other components include functions such as a protective layer that is optionally formed between the substrate 1 and the fine structure film 2 and / or between the fine structure film 2 and the light emitting portion 7. A membrane is mentioned.

1 has a structure in which the fine structure film 2 and the light emitting portion 7 are sequentially laminated on the substrate 1, the essential components in the light emitting device of the present invention are the light emitting portion and the fine structure film. It is. Therefore, when the function as a light-emitting element can be exhibited without a substrate, the substrate may not be provided. In this case, the light emitting element has a structure in which the fine structure film 2 and the light emitting portion 7 are laminated.
When the fine structure film 2 functions as a transmissive diffraction grating portion or a transmissive light scattering layer, the light emitted from the light emitting layer 5 passes through the fine structure film 2 and is emitted to the outside. The surface 2a of the microstructure film 2 on the side where the micropores 3 are formed becomes the light emitting surface of the light emitting element.
On the other hand, when the fine structure film 2 functions as a reflection type diffraction grating part or a reflection type light scattering layer, the light emitted from the light emitting layer 5 is reflected by the fine structure film 2 and then passes through the light emitting part 7. It passes through and is released to the outside. Therefore, the surface 6a of the second electrode 6 on the lower side in the figure becomes the light emitting surface.

1 has a structure in which the fine structure film 2 and the light emitting portion 7 are sequentially stacked on the substrate 1, but the order of the substrate, the fine structure film, and the light emitting portion in the light emitting element is limited to this. For example, a structure in which a light emitting portion and a fine structure film are sequentially stacked on a substrate may be used. The light emitting element having such a structure can also be configured as either a bottom emission type light emitting element or a top emission type light emitting element depending on the optical characteristics of the microstructure film to be used.
When the fine structure film functions as a transmissive diffraction grating part or a transmissive light scattering layer, the light emitted from the light emitting layer is emitted to the outside through the fine structure film. It becomes this light emitting element. In this case, the surface exposed to the outside of the fine structure film becomes the light emitting surface of the light emitting element.
On the other hand, when the fine structure film functions as a reflection type diffraction grating part or a reflection type light scattering layer, the light emitted from the light emitting layer is reflected by the fine structure film before the light emitting part and the substrate are Since it passes through and is emitted to the outside, a bottom emission type light emitting element is obtained. In this case, the surface exposed to the outside of the substrate becomes the light emitting surface of the light emitting element.

Hereinafter, each component of the light emitting device of the present invention will be described.
[substrate]
The physical properties required for the substrate 1 differ depending on whether the light emitting element 10 is a bottom emission type light emitting element or a top emission type light emitting element.
In the case of a bottom emission type light emitting element, light emitted from the light emitting layer 5 passes through the fine structure film 2 and the substrate 1 and is emitted to the outside. Therefore, the substrate 1 includes a light emitting layer such as a glass substrate. It is necessary to use a material that transmits light emitted from 5. In addition, the thickness of the board | substrate 1 is not specifically limited as long as the intended translucency can be exhibited.
On the other hand, in the case of a top emission type light emitting element, the substrate 1 is not required to have translucency, so that the substrate 1 can be formed of any material. Specific examples of the substrate 1 of the top emission type light emitting element include a glass substrate, a plastic substrate, a semiconductor substrate, and the like. The thickness of the substrate 1 is not particularly limited.

[Light emitting part]
The light-emitting portion 7 shown in FIG. 1 is a light-emitting portion of an EL element in which a light-emitting layer 5 that emits light when an electric field is applied is sandwiched between a first electrode 4 and a second electrode 6. As described above, the EL element in this specification includes a wide range of light emitting elements that emit light when an electric field is applied, and is an injection type such as an LED element in addition to an intrinsic EL element such as an organic EL element or an inorganic EL element. The EL element is also included. Therefore, the light emitting layer 5 may be configured as a light emitting layer of an injection type EL element such as an LED element, or may be configured as a light emitting layer of an intrinsic EL element such as an organic EL element or an inorganic EL element.

One of the first electrode 5 and the second electrode 7 is an anode, and the other is a cathode.
When the light emitting element 10 shown in FIG. 1 is a bottom emission type light emitting element, the first electrode 4 provided on the light emitting surface 1 a side out of the first electrode 4 and the second electrode 6 emits light from the light emitting layer 5. The transmitted light needs to be transmitted. On the other hand, when the light emitting element 10 shown in FIG. 1 is a top emission type light emitting element, both the first electrode 5 and the second electrode 7 need to transmit light emitted from the light emitting layer 5.
The thicknesses of the first electrode 5 and the second electrode 7 are not particularly limited as long as the original function as an electrode is expressed. For example, the thickness is within a range of 0.01 μm to 5 μm. Can do.

1 is an EL element, the light-emitting element of the present invention is not limited to an EL element, and may be a light-emitting element other than an EL element. However, in the light-emitting element of the present invention, the microstructure film having micropores functions as a light transmission type or light reflection type diffraction grating part or a light scattering layer. Preferably there is.
Note that when a light-emitting element other than an EL element is used, the light-emitting portion has a structure corresponding to the light-emitting element.

  Hereinafter, in the case where the light-emitting element is a bottom emission type organic EL element, the configuration of each part will be described in more detail.

(substrate)
The substrate 1 is preferably a substrate that does not scatter or attenuate the light emitted from the light emitting layer 5. Specific examples include zirconia-stabilized yttrium (YSZ), inorganic materials such as glass, polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, and polycycloolefin. , Norbornene resins, and organic materials such as poly (chlorotrifluoroethylene).
For example, when glass is used as the substrate, alkali-free glass is preferably used as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

  There is no restriction | limiting in particular about the shape of the board | substrate 1, a structure, a magnitude | size, etc., It can select suitably according to the use, the objective, etc. of a light emitting element (organic EL element). 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.

  The substrate 1 may be colorless and transparent, or may be colored and transparent, but is preferably colorless and transparent from the viewpoint that the light emitted from the light emitting layer 5 is not scattered or attenuated.

The substrate 1 can be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
As a material for the moisture permeation preventive layer (gas barrier layer), inorganic materials such as silicon nitride and silicon oxide are preferably used. The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method.
When a substrate made of a thermoplastic material is used, a hard coat layer, an undercoat layer, or the like may be further provided as necessary.

(anode)
The anode usually has a function as an electrode for supplying holes to the light emitting layer 5, and there is no particular limitation on the shape, structure, size, etc., and the use of the light emitting element (organic EL element) Depending on the purpose, it can be appropriately selected from known electrode materials.
As described above, in the case of the bottom emission type light emitting element, the first electrode 4 provided on the light emitting surface 1a side out of the first electrode 4 and the second electrode 6 is light emitted from the light emitting layer 5. However, the anode is usually provided as the transparent electrode.

  Suitable examples of the material for the anode include metals, alloys, metal oxides, conductive compounds, and mixtures thereof. Specific examples of the anode material include conductive metals such as tin oxide doped with antimony and fluorine (ATO, FTO), tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO). Metals such as oxides, gold, silver, chromium, nickel, and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, polyaniline, polythiophene, polypyrrole, etc. Organic conductive materials, and a laminate of these and ITO. Among these, conductive metal oxides are preferable, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like.

  The anode is composed of, for example, a wet method such as a printing method and a coating method, a physical method such as a vacuum deposition method, a sputtering method, and an ion plating method, and a chemical method such as a CVD and a plasma CVD method. It can be formed on the substrate in accordance with a method appropriately selected in consideration of suitability for the material to be used. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like.

  There is no restriction | limiting in particular as a formation position of an anode, According to the use and objective of a light emitting element (organic EL element), it can select suitably. However, as described above, it is preferable to form the first electrode 4 provided on the light emitting surface 1a side as an anode. The anode may be formed so as to cover the entire surface of one side of the light emitting layer 5, or may be formed so as to cover a part of the surface.

  The patterning for forming the anode may be performed by chemical etching such as photolithography, or may be performed by physical etching such as laser, or vacuum deposition or sputtering with a mask overlapped. It may be performed by a lift-off method or a printing method.

  The thickness of the anode can be appropriately selected depending on the material constituting the anode and cannot be generally defined, but is usually about 10 nm to 50 μm, and preferably 50 nm to 20 μm.

The resistance value of the anode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less. When the anode is a transparent electrode, it may be colorless and transparent or colored and transparent. In the case of the first electrode 4 formed on the light emitting surface 1a side, the transmittance of light emitted from the light emitting layer 5 is preferably 60% or more, and more preferably 70% or more.

  Note that the transparent anode is described in detail in Yutaka Sawada's “New Development of Transparent Electrode Film” published by CMC (1999), and the matters described here can be applied to the present invention. When using a plastic substrate with low heat resistance, a transparent anode formed using ITO or IZO at a low temperature of 150 ° C. or lower is preferable.

(cathode)
The cathode usually only has to have a function as an electrode for injecting electrons into the light emitting layer 5, and there is no particular limitation on the shape, structure, size, etc., and the use of the light emitting element (organic EL element), Depending on the purpose, it can be appropriately selected from known electrode materials.

  Examples of the material constituting the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Specific examples include alkali metals (eg, LI, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, magnesium. -Rare earth metals such as silver alloys, 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, as a material constituting the cathode, an alkali metal or an alkaline earth metal is preferable from the viewpoint of electron injecting property, and a material mainly composed of aluminum is 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 cathode materials are described in detail in JP-A-2-15595 and JP-A-5-121172, and the materials described in these publications can also be applied in the present invention.

The resistance value of the cathode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less.

  There is no restriction | limiting in particular about the formation method of a cathode, According to a well-known method, it can carry out. For example, the cathode described above is configured from 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, or a chemical method such as CVD or plasma CVD method. It can be formed according to a method appropriately selected in consideration of suitability with the material. For example, when a metal or the like is selected as the cathode material, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  Patterning when forming the cathode may be performed by chemical etching such as photolithography, physical etching by laser, or the like, or by vacuum deposition or sputtering with the mask overlaid. It may be performed by a lift-off method or a printing method.

There is no restriction | limiting in particular in the cathode formation position, According to the use and objective of a light emitting element (organic EL element), it can select suitably.
However, since the first electrode 4 provided on the light emitting surface 1a side is preferably formed as an anode as described above, the second electrode 6 is preferably formed as a cathode. The cathode may be formed so as to cover one whole surface of the light emitting layer 5 or may be formed so as to cover a part of the surface.

  A dielectric layer made of an alkali metal or alkaline earth metal fluoride or oxide may be inserted between the cathode and the light emitting layer in a thickness of 0.1 nm to 5 nm. This dielectric layer can also be regarded as a kind of electron injection layer. The dielectric layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

The thickness of the cathode can be appropriately selected depending on the material constituting the cathode and cannot be generally defined, but is usually about 10 nm to 5 μm, and preferably 50 nm to 1 μm.
Further, the cathode may be transparent or opaque. The transparent cathode can be formed by depositing a thin cathode material to a thickness of 1 nm to 10 nm and further laminating a transparent conductive material such as ITO or IZO.

(Light emitting layer)
When the light emitting layer 5 is used as a light emitting layer of an organic EL device, the light emitting layer 5 can have a structure in which one or more organic compound layers including an active layer are stacked. The active layer refers to a region where holes and electrons are combined, and emits light when the holes and electrons are combined in the region. The light emitting layer 5 may include a layer other than the active layer, and may include, for example, at least one of a hole transport layer and an electron transport layer in order to improve the coupling efficiency between holes and charges. In this case, the hole transport layer is inserted between the active layer and the anode, and the electron transport layer is inserted between the active layer and the cathode. The materials of the active layer, the hole transport layer, and the electron transport layer are not particularly limited, and any material can be used as long as it is an active layer material, a hole transport material, or an electron transport material usually used in an organic EL element. it can.

As a structure of the light emitting layer 5, the aspect laminated | stacked in order of the positive hole transport layer, the active layer, and the electron carrying layer from the anode side is preferable. Furthermore, a hole injection layer is provided between the hole transport layer and the anode, and / or an electron transport intermediate layer is provided between the active layer and the electron transport layer. Further, a hole transporting intermediate layer may be provided between the active layer and the hole transport layer, and similarly, an electron injection layer may be provided between the cathode and the electron transport layer.
Each layer may be divided into a plurality of secondary layers.

  Each layer constituting the light emitting layer 5 can be suitably formed by any of dry film forming methods such as vapor deposition and sputtering, transfer methods, printing methods, coating methods, ink jet methods, and spray methods.

The active layer may be composed of only a light emitting material, or may be configured as a mixed layer of a host material and a light emitting dopant. The luminescent dopant may be a fluorescent material or a phosphorescent material, and may be two or more kinds. The host material is preferably a charge transport material. The host material may be one type or two or more types, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed. Furthermore, the active layer may include a material that does not have charge transporting properties and does not emit light.
Further, the active layer may be one layer or two or more layers, and each layer may emit light in different emission colors.

  As the luminescent dopant, any of phosphorescent luminescent materials, fluorescent luminescent materials, and the like can be used as the dopant.

  The active layer can contain two or more kinds of luminescent dopants in order to improve color purity and to broaden the emission wavelength region. The light emitting dopant is a dopant satisfying the relationship of 1.2 eV> ΔIp> 0.2 eV and / or 1.2 eV> ΔEa> 0.2 eV with the host compound. It is preferable from the viewpoint.

《Phosphorescent dopant》
In general, examples of the phosphorescent light-emitting dopant include complexes containing a transition metal atom or a lanthanoid atom.
For example, the transition metal atom is not particularly limited, but preferably includes ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, gold, silver, copper, and platinum, and more preferably rhenium, iridium. And platinum, more preferably iridium and platinum.
Examples of lanthanoid atoms include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Among these lanthanoid atoms, neodymium, europium, and gadolinium are preferable.

  Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Listed by Yersin, “Photochemistry and Photophysics of Coordination Compounds”, published by Springer-Verlag, 1987, Akio Yamamoto, “Organic Metal Chemistry-Fundamentals and Applications,” published by Soukabo, 1982, etc. .

  The specific ligand is preferably a halogen ligand (preferably a chlorine ligand) or an aromatic carbocyclic ligand (for example, preferably 5 to 30 carbon atoms, more preferably 6 to 6 carbon atoms). 30, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a cyclopentadienyl anion, a benzene anion, or a naphthyl anion), a nitrogen-containing heterocyclic ligand (for example, preferably Has 5 to 30 carbon atoms, more preferably 6 to 30 carbon atoms, still more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and phenylpyridine, benzoquinoline, quinolinol, bipyridyl, or phenanthroline. Etc.), diketone ligand (for example, acetylacetone, etc.), carboxylic acid ligand (for example, preferably 2-30 carbon atoms, and more) Preferably, it has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, such as an acetic acid ligand), an alcoholate ligand (for example, preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms). More preferably, it has 6 to 20 carbon atoms, such as phenolate ligand), silyloxy ligand (for example, preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 3 to 3 carbon atoms). 20 such as trimethylsilyloxy ligand, dimethyl-tert-butylsilyloxy ligand, triphenylsilyloxy ligand), carbon monoxide ligand, isonitrile ligand, cyano ligand, Phosphorus ligand (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 3 to 20 carbon atoms, and particularly preferably 6 to 20 carbon atoms. A rephenylphosphine ligand), a thiolato ligand (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 6 to 20 carbon atoms, such as a phenylthiolato ligand) ), A phosphine oxide ligand (preferably having 3 to 30 carbon atoms, more preferably 8 to 30 carbon atoms, still more preferably 18 to 30 carbon atoms, such as a triphenylphosphine oxide ligand). More preferably, it is a nitrogen-containing heterocyclic ligand.

  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.

  Specific examples of the phosphorescent luminescent dopant include, for example, US Pat. No. 6,303,238, US Pat. No. 6,097,147, International Publication No. 00/57676, International Publication No. 00/70655, International Publication. No. 01/08230 pamphlet, WO 01/39234 pamphlet, WO 01/41512 pamphlet, WO 02/02714 pamphlet, WO 02 / 15645A1, WO 02/44189 pamphlet, WO 05/19373 pamphlet, JP 2001-247859 A, JP 2002-302671 A, JP 2002-117978 A, JP 2003-133074 A, JP 2002-235076 A, Open 200 No. -123982, JP 2002-170684 A, EP 121112257, JP 2002-226495, JP 2002-234894, JP 2001-247859, JP 2001-298470. JP, JP-A-2002-173684, JP-A-2002-203678, JP-A-2002-203679, JP-A-2004-357791, JP-A-2006-256999, JP-A-2007-19462 And phosphorescent compounds described in patent documents such as JP2007-84635A and JP2007-96259A, and more preferable phosphorescent luminescent dopants include Ir complexes, Pt complexes, Cu complex, Re complex, W complex, Rh complex, Ru complex, P Complexes, Os complexes, Eu complexes, Tb complexes, Gd complexes, and Dy complexes, and Ce complexes. Particularly preferred is an Ir complex, a Pt complex, or a Re complex, among which an Ir complex or a Pt complex containing at least one coordination mode of a metal-carbon bond, a metal-nitrogen bond, a metal-oxygen bond, and a metal-sulfur bond. Or a Re complex. Furthermore, from the viewpoints of luminous efficiency, driving durability, chromaticity, etc., an Ir complex, a Pt complex, or a Re complex containing a tridentate or higher polydentate ligand is particularly preferable.

《Fluorescent luminescent dopant》
Fluorescent light-emitting dopants are generally 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 (such as anthracene, phenanthroline, pyrene, perylene, rubrene, or pentacene) , 8-quinolinol metal complexes, various metal complexes represented by pyromethene complexes and rare earth complexes, polythiophene, polyphenylene, polyphenylene vinyl Polymeric compounds such as emission, organic silanes, and the like, and their derivatives.

  The luminescent dopant in the active layer is contained in an amount of 0.1% by mass to 50% by mass with respect to the total compound mass generally forming the active layer in the active layer. To 1 mass% to 50 mass%, and more preferably 2 mass% to 40 mass%.

  The thickness of the active layer is not particularly limited, but is usually preferably 2 nm to 500 nm, and more preferably 3 nm to 200 nm, and more preferably 5 nm to 100 nm, from the viewpoint of external quantum efficiency. More preferably.

<Host material>
As the host material, a hole transporting host material having excellent hole transportability (may be described as a hole transportable host) and an electron transporting host compound having excellent electron transportability (in the case of being described as an electron transporting host) Can be used).

《Hole-transporting host》
Specific examples of the hole transporting host include the following materials.
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 compound, polysilane compound, poly (N-vinylcarbazole), aniline copolymer, thiophene oligomer, polythiophene, etc. Conductive polymer oligomers, organic silanes, carbon films, and derivatives thereof.
Preferred are indole derivatives, carbazole derivatives, aromatic tertiary amine compounds, and thiophene derivatives, and more preferred are those having a carbazole group in the molecule. In particular, a compound having a t-butyl substituted carbazole group is preferable.

《Electron transporting host》
The electron transporting host in the active layer preferably has an electron affinity Ea of 2.5 eV or more and 3.5 eV or less from the viewpoint of improving durability and reducing driving voltage, and is 2.6 eV or more and 3.4 eV or less. More preferably, it is 2.8 eV or more and 3.3 eV or less. Further, from the viewpoint of improving durability and reducing driving voltage, the ionization potential Ip is preferably 5.7 eV or more and 7.5 eV or less, more preferably 5.8 eV or more and 7.0 eV or less, and 5.9 eV or more. More preferably, it is 6.5 eV or less.

Specific examples of such an electron transporting host include the following materials.
Pyridine, pyrimidine, triazine, imidazole, pyrazole, triazole, oxazole, oxadiazol, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, Fluorine-substituted aromatic compounds, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanines, and derivatives thereof (may form condensed rings with other rings), metal complexes and metals of 8-quinolinol derivatives Examples thereof include various metal complexes represented by metal complexes having phthalocyanine, benzoxazole or benzothiazol as a ligand.

Preferred examples of the electron transporting host include metal complexes, azole derivatives (benzimidazole derivatives, imidazopyridine derivatives, etc.), and azine derivatives (pyridine derivatives, pyrimidine derivatives, triazine derivatives, etc.). To metal complexes are preferred. The metal complex is more preferably a metal complex having a ligand having at least one nitrogen atom, oxygen atom or sulfur atom coordinated to the metal.
The metal ion in the metal complex is not particularly limited, but is preferably beryllium ion, magnesium ion, aluminum ion, gallium ion, zinc ion, indium ion, tin ion, platinum ion, or palladium ion, more preferably beryllium ion, Aluminum ion, gallium ion, zinc ion, platinum ion, or palladium ion, and more preferably aluminum ion, zinc ion, or palladium ion.

  There are various known ligands contained in the metal complex. For example, “Photochemistry and Photophysics of Coordination Compounds”, Springer-Verlag, H.C. Examples include the ligands described in Yersin, published in 1987, “Organometallic Chemistry: Fundamentals and Applications”, Sakai Hanafusa, Yamamoto Akio, published in 1982, and the like.

The ligand is preferably a nitrogen-containing heterocyclic ligand (preferably having 1 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 3 to 15 carbon atoms, and a monodentate ligand. May be a bidentate or higher ligand, preferably a bidentate or higher and a hexadentate or lower ligand, and a bidentate or higher and lower 6 or lower ligand and a monodentate mixed ligand are also preferable. .
Examples of the ligand include an azine ligand (for example, pyridine ligand, bipyridyl ligand, terpyridine ligand, etc.), a hydroxyphenylazole ligand (for example, hydroxyphenylbenzimidazole coordination). And a hydroxyphenyl benzoxazole ligand, a hydroxyphenyl imidazole ligand, a hydroxyphenylimidazopyridine ligand, etc.), an alkoxy ligand (preferably having 1 to 30 carbon atoms, more preferably 1 carbon atom). To 20, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy), aryloxy ligands (preferably 6 to 30 carbon atoms, more preferably 6-20 carbon atoms, particularly preferably 6-12 carbon atoms, for example phenyl And xyl, 1-naphthyloxy, 2-naphthyloxy, 2,4,6-trimethylphenyloxy, 4-biphenyloxy, etc.), heteroaryloxy ligands (preferably having 1 to 30 carbon atoms, more preferably Has 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, and the like, and alkylthio ligands (preferably having 1 to 30 carbon atoms, more preferably Has 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylthio and ethylthio.), An arylthio ligand (preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms). Particularly preferably 6 to 12 carbon atoms, such as phenylthio). A reelthio ligand (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, And 2-benzthiazolylthio), siloxy ligands (preferably having 1 to 30 carbon atoms, more preferably 3 to 25 carbon atoms, and particularly preferably 6 to 20 carbon atoms). Phenylsiloxy group, triethoxysiloxy group, triisopropylsiloxy group, etc.), aromatic hydrocarbon anion ligand (preferably having 6 to 30 carbon atoms, more preferably 6 to 25 carbon atoms, particularly preferably C6-C20, for example, a phenyl anion, a naphthyl anion, an anthranyl anion, etc.). Aromatic heterocyclic anion ligand (preferably having 1 to 30 carbon atoms, more preferably 2 to 25 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as pyrrole anion, pyrazole anion, pyrazole anion, triazole anion, Examples thereof include an oxazole anion, a benzoxazole anion, a thiazole anion, a benzothiazole anion, a thiophene anion, and a benzothiophene anion. ), An indolenine anion ligand, etc., preferably a nitrogen-containing heterocyclic ligand, an aryloxy ligand, a heteroaryloxy group, or a siloxy ligand, more preferably a nitrogen-containing heterocyclic ring. A ligand, an aryloxy ligand, a siloxy ligand, an aromatic hydrocarbon anion ligand, or an aromatic heterocyclic anion ligand.

  Examples of the electron-transporting host that is a metal complex include, for example, Japanese Patent Application Laid-Open No. 2002-235076, Japanese Patent Application Laid-Open No. 2004-214179, Japanese Patent Application Laid-Open No. 2004-221062, Japanese Patent Application Laid-Open No. 2004-221665, and Japanese Patent Application Laid-Open No. 2004-2004. And the compounds described in JP-A No. 221068 and JP-A No. 2004-327313.

  In the active layer, the triplet lowest excitation level (T1) of the host material is preferably higher than T1 of the phosphorescent material from the viewpoint of color purity, luminous efficiency, and driving durability.

  In addition, the content of the host compound is not particularly limited, but may be 15% by mass or more and 95% by mass or less with respect to the total compound mass forming the active layer from the viewpoint of luminous efficiency and driving voltage. preferable.

(Hole injection layer, hole transport layer)
The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side. The hole injection material and the hole transport material used for these layers may be a low molecular compound or a high molecular compound.
Specifically, pyrrole derivatives, carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styryl Anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, phthalocyanine compounds, porphyrin compounds, thiophene derivatives, organosilane derivatives, carbon, etc. It is preferable that it is a layer containing.

An electron-accepting dopant can be contained in the hole injection layer or the hole transport layer of the organic EL element. As the electron-accepting dopant introduced into the hole-injecting layer or the hole-transporting layer, an inorganic compound or an organic compound can be used as long as it has an electron-accepting property and oxidizes an organic compound.
Specifically, 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.

  In the case of an organic compound, a compound having a nitro group, halogen, cyano group, trifluoromethyl group or the like as a substituent, a quinone compound, an acid anhydride compound, fullerene C60, or the like can be preferably used. In addition, JP-A-6-212153, JP-A-11-111463, JP-A-11-251067, JP-A-2000-196140, JP-A-2000-286054, JP-A-2000-315580 JP, JP-A-2001-102175, JP-A-2001-160493, JP-A-2002-252085, JP-A-2002-56985, JP-A-2003-157981, JP-A-2003-217862 The compounds described in JP-A 2003-229278, JP-A 2004-342614, JP-A 2005-72012, JP-A 2005-166637, JP-A 2005-209643 and the like are preferably used. Can be used.

  Among these, hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, p-fluoranyl, p-chloranil, p-bromanyl, p-benzoquinone, 2,6-dichlorobenzoquinone, 2 , 5-dichlorobenzoquinone, 1,2,4,5-tetracyanobenzene, 1,4-dicyanotetrafluorobenzene, 2,3-dichloro-5,6-dicyanobenzoquinone, p-dinitrobenzene, m-dinitrobenzene, o-dinitrobenzene, 1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1,3-dinitronaphthalene, 1,5-dinitronaphthalene, 9,10-anthraquinone, 1,3,6,8-tetranitrocarbazole, 2,4,7-trinitro-9- Preferred are luolenone, 2,3,5,6-tetracyanopyridine, or C60, hexacyanobutadiene, hexacyanobenzene, tetracyanoethylene, tetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, p-fluoranyl, p-chloranil. P-bromanyl, 2,6-dichlorobenzoquinone, 2,5-dichlorobenzoquinone, 2,3-dichloronaphthoquinone, 1,2,4,5-tetracyanobenzene, 2,3-dichloro-5,6-dicyanobenzoquinone Or 2,3,5,6-tetracyanopyridine is more preferable, and tetrafluorotetracyanoquinodimethane is particularly preferable.

  These electron-accepting dopants may be used alone or in combination of two or more. Although the usage-amount of an electron-accepting dopant changes with kinds of material, it is preferable that it is 0.01 mass%-50 mass% with respect to hole transport layer material, and it is 0.05 mass%-20 mass%. It is further more preferable and it is especially preferable that it is 0.1 mass%-10 mass%.

The thicknesses of the hole injection layer and the hole transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the hole transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the hole injection layer is preferably 0.1 nm to 200 nm, more preferably 0.5 nm to 100 nm, and still more preferably 1 nm to 100 nm.
The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the materials described above, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. .

(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 injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
Specifically, pyridine derivatives, quinoline derivatives, pyrimidine derivatives, pyrazine derivatives, phthalazine derivatives, phenanthroline derivatives, triazine derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone Derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, naphthalene, perylene and other aromatic ring tetracarboxylic acid anhydrides, phthalocyanine derivatives, 8-quinolinol derivative metal complexes, Metal phthalocyanines, various metal complexes represented by metal complexes with benzoxazole and benzothiazole as ligands, organosilane derivatives represented by siloles Body, or the like is preferably a layer containing.

The electron injection layer or the electron transport layer of the organic EL device can contain an electron donating dopant. The electron donating dopant introduced into the electron injecting layer or the electron transporting layer only needs to have an electron donating property and 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 and reducing organic compounds 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, Gd , And Yb. Examples of the reducing organic compound include nitrogen-containing compounds, sulfur-containing compounds, and phosphorus-containing compounds.
In addition to these, it is described in JP-A-6-212153, JP-A-2000-196140, JP-A-2003-68468, JP-A-2003-229278, JP-A-2004-342614, and the like. Materials can be used.

  These electron donating dopants may be used alone or in combination of two or more. The amount 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. Is more preferable, and 2.0 mass% to 70 mass% is particularly preferable.

The thicknesses of the electron injection layer and the electron transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the electron transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and still more preferably 0.5 nm to 50 nm.
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 blocking layer)
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the active layer from passing through to the cathode side. A hole blocking layer can be provided as an organic compound layer adjacent to the active layer on the cathode side.
Examples of the compound constituting the hole blocking layer include aluminum complexes such as BAlq, triazole derivatives, phenanthroline derivatives such as BCP, and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm.
The hole 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.

(Electronic block layer)
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the active layer from passing through to the anode side. An electron blocking layer can be provided as the organic compound layer adjacent to the active layer on the anode side. As examples of the compound constituting the electron blocking layer, for example, those mentioned as the hole transport material described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The hole 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.

  In order to improve luminous efficiency, a charge generation layer may be provided between a plurality of active layers. Here, the charge generation layer is a layer having a function of generating charges (holes and electrons) when an electric field is applied and a function of injecting the generated charges into a layer adjacent to the charge generation layer.

The material for forming the charge generation layer may be any material having the above-described function, and may be formed of a single compound or a plurality of compounds.
Specifically, it may be a conductive material, a semiconductive material such as a doped organic layer, or an electrically insulating material. Examples thereof include materials described in Japanese Patent Application Publication Nos. 11-329748, 2003-272860, and 2004-39617.
More specifically, transparent conductive materials such as ITO and IZO (indium zinc oxide), fullerenes such as C60, conductive organic materials such as oligothiophene, metal phthalocyanines, metal-free phthalocyanines, metal porphyrins, metal-free Conductive organic materials such as porphyrins, metal materials such as Ca, Ag, Al, Mg: Ag alloy, Al: Li alloy, Mg: Li alloy, hole conductive material, electron conductive material, and a mixture thereof May be used.
Examples of the hole conductive material include those obtained by doping a hole transporting organic material such as 2-TNATA or NPD with an oxidant having an electron withdrawing property such as F4-TCNQ, TCNQ, or FeCl _3. The electron conductive material includes an electron transport organic material doped with a metal or metal compound having a work function of less than 4.0 eV, an N type conductive polymer, N type Type semiconductors. Examples of the N-type semiconductor include N-type Si, N-type CdS, and N-type ZnS. Examples of the P-type semiconductor include P-type Si, P-type CdTe, and P-type CuO.
An electric insulating material such as V ₂ O ₅ can also be used for the charge generation layer.

  The charge generation layer may be a single layer or a stack of a plurality of layers. A structure in which a plurality of layers are stacked includes a conductive material such as a transparent conductive material and a metal material and a hole conductive material, or a structure in which an electron conductive material is stacked, and the above hole conductive material and electron conductive And a layer having a structure in which a functional material is laminated.

In general, it is preferable to select a film thickness and a material for the charge generation layer so that the visible light transmittance is 50% or more. The film thickness is not particularly limited, but is preferably 0.5 nm to 200 nm, more preferably 1 nm to 100 nm, still more preferably 3 nm to 50 nm, and particularly preferably 5 nm to 30 nm.
The method for forming the charge generation layer is not particularly limited, and the method for forming the organic compound layer such as the active layer described above can be used.

The charge generation layer is formed between two or more active layers, and the anode side and the cathode side of the charge generation layer may contain a material having a function of injecting charges into adjacent layers. In order to improve the electron injection property to the layer adjacent to the anode side, for example, an electron injection compound such as BaO, SrO, Li ₂ O, LiCl, LiF, MgF ₂ , MgO, or CaF _{2 is used} as the anode of the charge generation layer. It may be laminated on the side.
In addition to the contents mentioned above, based on the description in JP 2003-45676 A, US Pat. No. 6,337,492, US Pat. No. 6,107,734, US Pat. No. 6,872,472, etc. The material of the generation layer can be selected.

(Drive)
The organic EL element can obtain light emission by applying a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. .
As for the driving method of the organic EL element, JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234665, The driving methods described in each publication of Japanese Utility Model Publication No. 8-2441047, Japanese Patent No. 2784615, US Pat. No. 5,828,429, US Pat. No. 6,023,308, and the like can be applied.

[Microstructure film]
The microstructure film 2 is a light emitting surface of the light emitting element (1a when the light emitting element 10 shown in FIG. 1 is a bottom emission type light emitting element, and 6a when the light emitting element 10 shown in FIG. 1 is a top emission type light emitting element). A micropore 3 is formed on the surface 2a parallel to the light emitting surface of the light emitting element.
Here, the average pore diameter of the micropores 3 on the surface 2a is 5 to 1000 nm, and the average pore density of the micropores 3 on the surface 2a is 1 × 10 ⁶ to 1 × 10 ¹⁰ holes / mm ² . For the micropore 3, the degree of ordering defined by the following formula (i) is 50% or more.
Ordering degree (%) = B / A × 100 (i)
In formula (i), A represents the total number of micropores in the measurement range. B is centered on the center of gravity of one micropore, and when a circle with the shortest radius inscribed in the edge of another micropore is drawn, the center of gravity of the micropores other than the one micropore is inside the circle. This represents the number in the measurement range of one micropore that will contain six.

Here, FIG. 2 is an explanatory diagram of a method for calculating the degree of ordering of micropores. The above formula (i) will be described more specifically with reference to FIG.
The micropore 101 shown in FIG. 2 (A) draws a circle 103 (inscribed in the micropore 102) having the shortest radius and centering on the center of gravity of the micropore 101 and inscribed in the edge of another micropore. In this case, the center of the circle 103 includes six centroids of micropores other than the micropore 101. Therefore, the micropore 101 is included in B.
The micropore 104 shown in FIG. 2 (B) draws a circle 106 (inscribed in the micropore 105) having the shortest radius centered on the center of gravity of the micropore 104 and inscribed in the edge of another micropore. In such a case, the center of gravity of the micropores other than the micropores 104 is included inside the circle 106. Therefore, the micropore 104 is not included in B.
Further, the micropore 107 shown in FIG. 2B is centered on the center of gravity of the micropore 107 and has the shortest radius 109 inscribed in the edge of another micropore (inscribed in the micropore 108). Is drawn, the circle 109 includes seven centroids of micropores other than the micropore 107. Therefore, the micropore 107 is not included in B.

  In the fine structure film 2, the micropores 3 satisfying the above average pore diameter, average pore density, and degree of ordering are formed on the surface 2a parallel to the light emitting surface (1a or 6a) of the light emitting element 10. It functions as a light transmission type or light reflection type diffraction grating part or a light scattering layer for the light emitted from the light emitting layer 5. Thereby, the extraction efficiency of the light emitted from the light emitting layer 5 is improved. The microstructure film 2 functioning as a diffraction grating portion or a light scattering layer is formed with densely arranged micropores, and therefore has excellent uniformity of luminance in the direction of the light emitting surface, and luminance in the direction of the light emitting surface. There will be no shading.

In order to effectively exhibit the function as the diffraction grating portion or the light scattering layer described above, the average pore diameter of the micropore is preferably 10 to 800 nm, and more preferably 15 to 500 nm.
Similarly, the average pore density of the micropores is preferably 5 × 10 ^{6 to} 5 × 10 ⁹ pieces / mm ² , and more preferably 1 × 10 ⁷ to 1 × 10 ⁹ pieces / mm ^2. .
Similarly, the degree of ordering of the micropores is preferably 60% or more, and more preferably 70% or more.

Further, when the fine structure film functions as a diffraction grating part, it is preferable that the period of the unevenness of the diffraction grating part, which is defined as the distance between adjacent central points of the micropores, satisfies the following.
The guided light inside the light emitting element includes the width of the waveguide layer (in the case of the light emitting element 10 shown in FIG. 1, the fine structure film 2), the adjacent cladding layer (in the case of the light emitting element 10 shown in FIG. 1, the first electrode 4). ) And parameters such as the refractive index of the waveguiding layer, the waveguiding light wavelength, and the like. When the waveguide wavelength in vacuum is λ, the refractive index of the waveguide layer is n, the reflection angle of the m-th order guided light is θ _m , the concave / convex period of the diffraction grating portion is Λ, and v is an integer, the concave / convex period Λ is When expressed by the mathematical expression (ii), the guided light is diffracted in the direction perpendicular to the light emitting surface.
Λ = v · λ / n · sin θ _m (ii)

  Therefore, a diffraction grating having irregularities formed with a period satisfying the relationship represented by the above formula (ii) (in the case of the present invention, the distance between adjacent center points satisfies the relationship represented by the above formula (ii). The micro-structure film in which pores are formed) can diffract light that has been guided inside the light emitting element in the direction perpendicular to the light emitting surface, and the diffracted light is emitted to the outside. become. In particular, when the value of v is -1, that is, it is preferable to determine the period so that -1st order diffracted light is generated in the vertical direction. This is because the −1st order diffraction efficiency is larger than the diffraction efficiency of other orders, and the increase rate of the light extraction efficiency becomes the most remarkable.

The thickness of the microstructure film 2 is preferably 0.05 μm to 150 μm, more preferably 0.10 to 100 μm, and particularly preferably 0.20 to 50 μm.
If the thickness of the microstructure film 2 is more than 150 μm, the light transmission itself is deteriorated when functioning as a transmission type diffraction grating portion or a transmission type light scattering layer, which is not preferable. On the other hand, when the thickness of the fine structure film 2 is less than 0.05 μm, the strength of the fine structure film is impaired, which is not preferable.

The microstructure film 2 is not particularly limited as long as it has micropores that satisfy the above average pore diameter, average pore density, and degree of ordering on its surface, but the metal surface is a film of an oxide of the metal by anodic oxidation. An anodized film obtained by anodizing a material derived from a valve metal having the characteristics covered with a metal, more specifically, obtained by anodizing a substrate made of the valve metal or its alloy. The anodic oxide film to be formed is preferable for forming a microstructure film having micropores on its surface that satisfy the above average pore size, average pore density, and degree of ordering. Specific examples of the valve metal include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony.
Among these, the regularity of the micropores formed on the surface of the anodized film, more specifically, the regularity of the pore arrangement of the micropores is excellent. An aluminum anodic oxide film is preferred. The aluminum anodic oxide film is a transparent film, and the resulting microstructure film functions as a transmissive diffraction grating portion or a transmissive light scattering layer.

Hereinafter, preparation of an aluminum anodic oxide film suitable as a microstructure film in the light emitting device of the present invention will be described.
<Aluminum substrate>
The aluminum substrate is not particularly limited, and specific examples thereof include a pure aluminum plate; an alloy plate containing aluminum as a main component and containing a small amount of foreign elements; high-purity aluminum was vapor-deposited on low-purity aluminum (for example, recycled material). Examples of the substrate include: a substrate obtained by coating a surface of silicon wafer, quartz, glass or the like with a method such as vapor deposition or sputtering; a resin substrate obtained by laminating aluminum; and the like.

When the anodizing process described later is performed on the aluminum substrate, the surface on which the anodizing process is performed preferably has a higher aluminum purity. Specifically, the aluminum purity is preferably 99.5% by mass or more, more preferably 99.9% by mass or more, and further preferably 99.99% by mass or more.
In particular, when the aluminum purity is in the above range, the regularity of the pore arrangement of the micropores formed on the surface of the anodized aluminum film formed by anodizing becomes sufficient, and the transmission type diffraction grating of the light emitting element Part or a transmissive light scattering layer, it is preferable from the viewpoint of improving the luminance uniformity of the light emitting element.

  In addition, when performing the anodizing process to be described later on the aluminum substrate, the surface to be anodized is preferably subjected to a degreasing process and a mirror finishing process in advance, and in particular, from the viewpoint of improving the regularity of the pore arrangement. Therefore, heat treatment is preferably performed.

<Heat treatment>
When heat treatment is performed, it is preferably performed at 200 to 350 ° C. for about 30 seconds to 2 minutes. Specifically, for example, a method of placing an aluminum substrate in a heating oven can be used.
By performing such heat treatment, the regularity of the arrangement of micropores formed on the surface of the anodized film is improved.
Moreover, it is preferable to cool the aluminum substrate after heat treatment rapidly. As a method for cooling, for example, a method of directly putting it into water or the like can be mentioned.

<Degreasing treatment>
The degreasing treatment uses acid, alkali, organic solvent, etc. to dissolve and remove the organic components such as dust, fat, and resin adhered to the surface of the aluminum substrate, and in each treatment described later due to the organic components. This is done for the purpose of preventing the occurrence of defects.

Specifically, as the degreasing treatment, for example, a method in which an organic solvent such as various alcohols (for example, methanol), various ketones (for example, methyl ethyl ketone), benzine, volatile oil or the like is brought into contact with the aluminum substrate surface at room temperature (organic Solvent method); a method of bringing a liquid containing a surfactant such as soap or neutral detergent into contact with the aluminum substrate surface at a temperature from room temperature to 80 ° C., and then washing with water (surfactant method); concentration of 10 to 200 g A method in which an aqueous solution of sulfuric acid / L is brought into contact with an aluminum substrate surface for 30 to 80 seconds at a temperature from room temperature to 70 ° C. and then washed with water; an aqueous sodium hydroxide solution having a concentration of 5 to 20 g / L is applied to the aluminum substrate surface at room temperature. while contacting about seconds, the aluminum substrate surface and the electrolyte by passing a direct current of a current density of 1 to 10 a / dm ² in the cathode, the , A method of neutralizing by bringing a nitric acid aqueous solution having a concentration of 100 to 500 g / L into contact; while bringing various known anodizing electrolytes into contact with the metal substrate surface at room temperature, the aluminum substrate surface is used as a cathode and the current density is 1 to 1. A method in which a direct current of 10 A / dm ² is applied or an alternating current is applied for electrolysis; an alkaline aqueous solution having a concentration of 10 to 200 g / L is brought into contact with the aluminum substrate surface at 40 to 50 ° C. for 15 to 60 seconds, and then A method of neutralizing by bringing a nitric acid aqueous solution having a concentration of 100 to 500 g / L into contact; an emulsion obtained by mixing light oil, kerosene, etc. with a surfactant, water, etc. is brought into contact with the aluminum substrate surface at a temperature from room temperature to 50 ° C. Then, a method of washing with water (emulsification and degreasing method); a mixed solution of sodium carbonate, phosphates, surfactant and the like on the aluminum substrate surface at a temperature from room temperature to 50 ° C. 0 seconds is contacted, then, a method of washing with water (phosphate method); and the like.

  Among these, the organic solvent method, the surfactant method, the emulsion degreasing method, and the phosphate method are preferable from the viewpoint that the fat content on the surface of the aluminum substrate can be removed while the aluminum hardly dissolves.

  Moreover, a conventionally well-known degreasing agent can be used for a degreasing process. Specifically, for example, various commercially available degreasing agents can be used by a predetermined method.

<Mirror finish processing>
The mirror finishing process is performed in order to eliminate unevenness on the surface of the aluminum substrate, for example, rolling streaks generated during the rolling of the aluminum substrate, and improve the uniformity and reproducibility of the sealing process by an electrodeposition method or the like.
The mirror finishing process is not particularly limited, and a conventionally known method can be used. Examples thereof include mechanical polishing, chemical polishing, and electrolytic polishing.

  Examples of the mechanical polishing include a method of polishing with various commercially available polishing cloths, a method of combining various commercially available abrasives (for example, diamond, alumina) and a buff. Specifically, when an abrasive is used, a method in which the abrasive used is changed from coarse particles to fine particles over time is preferably exemplified. In this case, the final polishing agent is preferably # 1500. Thereby, the glossiness can be 50% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 50% or more).

As chemical polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. Examples thereof include various methods described in 164 to 165.
Further, phosphoric acid - nitric acid method, Alupol I method, Alupol V method, Alcoa R5 _{method, H 3 PO 4 -CH 3 COOH} -Cu _{method, H 3 PO 4 -HNO 3 -CH} 3 COOH method are preferable. Among these, the phosphoric acid-nitric acid method, the H ₃ PO ₄ —CH ₃ COOH—Cu method, and the H ₃ PO ₄ —HNO ₃ —CH ₃ COOH method are preferable.
By chemical polishing, the glossiness can be made 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

As electrolytic polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. 164-165; various methods described in US Pat. No. 2,708,655; “Practical Surface Technology”, vol. 33, no. 3, 1986, p. The method described in 32-38;
By electropolishing, the gloss can be 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

  These methods can be used in appropriate combination. Specifically, for example, a method of performing mechanical polishing in which the abrasive is changed from coarse particles to fine particles with time, and then performing electrolytic polishing is preferable.

By mirror finishing, for example, a surface having an average surface roughness R _{a of} 0.1 μm or less and a glossiness of 50% or more can be obtained. The average surface roughness _Ra is preferably 0.03 μm or less, and more preferably 0.02 μm or less. Further, the glossiness is preferably 70% or more, and more preferably 80% or more.
The glossiness is a regular reflectance obtained in accordance with JIS Z8741-1997 “Method 3 60 ° Specular Gloss” in the direction perpendicular to the rolling direction. Specifically, using a variable angle gloss meter (for example, VG-1D, manufactured by Nippon Denshoku Industries Co., Ltd.), when the regular reflectance is 70% or less, the incident reflection angle is 60 degrees and the regular reflectance is 70%. In the case of exceeding, the incident / reflection angle is 20 degrees.

<Anodizing treatment>
The anodizing treatment is a treatment for forming an anodized film having micropores on the surface of the aluminum substrate by anodizing the aluminum substrate.
As the anodizing treatment, a conventionally known method can be used. Specifically, it is preferable to use the self-ordering method described later.

The self-ordering method is a method for improving the regularity by utilizing the property that the micropores formed in the anodic oxide film are regularly arranged and removing the factors that disturb the regular arrangement. Specifically, a high-purity aluminum substrate is used, and an anodized film is formed at a low speed over a long period of time (for example, several hours to several tens of hours) at a voltage according to the type of the electrolytic solution.
In this method, since the pore diameter depends on the voltage, a desired pore diameter can be obtained to some extent by controlling the voltage.

  In order to form micropores by the self-ordering method, anodizing treatment (a-1) described later may be performed, but preferably anodizing treatment (a-1) described later, film removal treatment (a- It is preferable to form by the method of implementing 2) and re-anodizing treatment (a-3) in this order.

<Anodizing treatment (a-1)>
The average flow rate during the anodizing treatment (a-1) is preferably 0.5 to 20.0 m / min, more preferably 1.0 to 15.0 m / min, and 2.0 More preferably, it is -10.0 m / min. By performing the anodic oxidation treatment at a flow rate in the above range, micropores having uniform and high regularity can be formed.
Moreover, the method of flowing the electrolytic solution under the above-mentioned conditions is not particularly limited, but, for example, a method using a general stirring device such as a stirrer is used. In particular, it is preferable to use a stirrer that can control the stirring speed with a digital display because the average flow rate can be controlled. Examples of such a stirring apparatus include “Magnetic Stirrer HS-50D (manufactured by AS ONE)” and the like.

For the anodizing treatment (a-1), for example, a method in which an aluminum substrate is used as an anode in a solution having an acid concentration of 0.01 to 5 mol / L can be used.
The solution used for the anodizing treatment (a-1) is preferably an acid solution, and sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid, glycolic acid, tartaric acid, Malic acid, citric acid, and the like are more preferable, and sulfuric acid, phosphoric acid, and oxalic acid are particularly preferable. These acids can be used alone or in combination of two or more.

The conditions for the anodizing treatment (a-1) vary depending on the electrolyte used, and thus cannot be determined unconditionally. In general, however, the electrolyte concentration is 0.01 to 5 mol / L, and the solution temperature is -10 to 10. 30 ° C., a current density of 0.01~20A / dm ^2, voltage 3～300V, preferably an electrolysis time of from 0.5 to 30 hours, electrolyte concentration 0.05 to 3 mol / L, solution temperature -5 to 25 It is more preferable that it is C, current density 0.05-15A / dm < ² >, voltage 5-250V, electrolysis time 1-25 hours, electrolyte concentration 0.1-1 mol / L, liquid temperature 0-20 degreeC, current More preferably, the density is 0.1 to 10 A / dm ² , the voltage is 10 to 200 V, and the electrolysis time is 2 to 20 hours.

  The treatment time for the anodizing treatment (a-1) is preferably 0.5 minutes to 16 hours, more preferably 1 minute to 12 hours, and even more preferably 2 minutes to 8 hours.

  The anodizing treatment (a-1) can be performed under a constant voltage, or a method of changing the voltage intermittently or continuously. In this case, it is preferable to decrease the voltage sequentially. This makes it possible to reduce the resistance of the anodized film, and fine micropores are generated in the anodized film, which is preferable in terms of improving uniformity, particularly when sealing treatment is performed by electrodeposition. .

  The thickness of the anodized film formed by such anodizing treatment (a-1) is preferably 0.1 to 2000 μm, more preferably 1 to 1000 μm, and 10 to 500 μm. Is more preferable.

Moreover, it is preferable that the average pore diameter of the micropore formed by such anodizing treatment (a-1) is 0.01 to 0.5 μm. Hereinafter, in this specification, the opening diameter of the micropore is referred to as “pore diameter”.
Also, micropores formed by such anodizing treatment (a-1), in the range of 1 [mu] m ^2, the dispersion of the pore diameter, preferably has an average is within 3% of the pore diameter, within 2% by More preferably. The average pore diameter and the dispersion of the pore diameter can be obtained by the following equations, respectively.
Average pore diameter: μ _x = (1 / n) ΣXi
Dispersion of pore diameter: σ ² = (1 / n) (ΣXi ² ) −μ _x ²
Dispersion / average diameter = σ / μ _x ≦ 0.03
Here, Xi is one pore diameter measured in the range of 1 μm ² .

Furthermore, the average pore density of the micropores formed by such anodizing treatment (a-1) is preferably 50 to 1500 / μm ² .
Further, the area ratio occupied by the micropores formed by such anodizing treatment (a-1) is preferably 20 to 50%.
Here, the area ratio occupied by the micropores is defined by the ratio of the total area of the opening portions of the micropores to the area of the surface of the aluminum anodized film.

<Film removal treatment (a-2)>
The film removal process (a-2) is a process for dissolving and removing the anodized film formed on the surface of the aluminum substrate by the anodizing process (a-1).

  Since the anodic oxide film has higher regularity as it gets closer to the aluminum substrate, the anodic oxide film once removed by this film removal treatment (a-2) and remaining on the surface of the aluminum substrate. The bottom portion can be exposed on the surface to obtain regular depressions. Therefore, in the film removal process (a-2), the aluminum substrate is not dissolved, but only the anodized film made of alumina (aluminum oxide) is dissolved.

  Alumina solution includes chromium compound, nitric acid, phosphoric acid, zirconium compound, titanium compound, lithium salt, cerium salt, magnesium salt, sodium fluorosilicate, zinc fluoride, manganese compound, molybdenum compound, magnesium compound, barium compound and An aqueous solution containing at least one selected from the group consisting of simple halogens is preferred.

Specific examples of the chromium compound include chromium (III) oxide and anhydrous chromium (VI) acid.
Examples of the zirconium-based compound include zircon ammonium fluoride, zirconium fluoride, and zirconium chloride.
Examples of the titanium compound include titanium oxide and titanium sulfide.
Examples of the lithium salt include lithium fluoride and lithium chloride.
Examples of the cerium salt include cerium fluoride and cerium chloride.
Examples of the magnesium salt include magnesium sulfide.
Examples of the manganese compound include sodium permanganate and calcium permanganate.
Examples of the molybdenum compound include sodium molybdate.
Examples of magnesium compounds include magnesium fluoride pentahydrate.
Examples of barium compounds include barium oxide, barium acetate, barium carbonate, barium chlorate, barium chloride, barium fluoride, barium iodide, barium lactate, barium oxalate, barium perchlorate, barium selenate, selenite. Examples thereof include barium, barium stearate, barium sulfite, barium titanate, barium hydroxide, barium nitrate, and hydrates thereof. Among the barium compounds, barium oxide, barium acetate, and barium carbonate are preferable, and barium oxide is particularly preferable.
Examples of halogen alone include chlorine, fluorine, and bromine.

Among them, the alumina solution is preferably an aqueous solution containing an acid. Examples of the acid include sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, and the like, and a mixture of two or more acids may be used.
The acid concentration is preferably 0.01 mol / L or more, more preferably 0.05 mol / L or more, and still more preferably 0.1 mol / L or more. There is no particular upper limit, but generally it is preferably 10 mol / L or less, more preferably 5 mol / L or less. An unnecessarily high concentration is not economical, and if it is higher, the aluminum substrate may be dissolved.

  The alumina solution is preferably −10 ° C. or higher, more preferably −5 ° C. or higher, and still more preferably 0 ° C. or higher. In addition, since the starting point of ordering will be destroyed and disturbed if it processes using the boiling alumina solution, it is preferable to use it without boiling.

  The alumina solution dissolves alumina and does not dissolve aluminum. Here, the alumina solution may not dissolve aluminum substantially or may dissolve it slightly.

  The film removal treatment (a-2) is performed by bringing the aluminum substrate on which the anodized film is formed into contact with the above-described alumina solution. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred.

The dipping method is a treatment in which an aluminum substrate on which an anodized film is formed is dipped in the above-described alumina solution. Stirring during the dipping process is preferable because a uniform process is performed.
The dipping treatment time is preferably 10 minutes or longer, more preferably 1 hour or longer, and further preferably 3 hours or longer and 5 hours or longer.

<Re-anodizing treatment (a-3)>
After removing the anodic oxide film by the film removal treatment (a-2) to form regular depressions on the surface of the aluminum substrate, the degree of ordering of the micropores is higher by performing the anodic oxidation treatment again. An anodized film can be formed.
For the re-anodizing treatment (a-3), a conventionally known method can be used, but it is preferably performed under the same conditions as the above-described anodizing treatment (a-1).
Also, a method of repeatedly turning on and off the current intermittently while keeping the DC voltage constant, and a method of repeatedly turning on and off the current while intermittently changing the DC voltage can be suitably used. According to these methods, fine micropores are generated in the anodized film, which is preferable in terms of improving the uniformity of the pore diameter.

When the re-anodizing treatment (a-3) is performed at a low temperature, the arrangement of micropores becomes regular and the pore diameter becomes uniform.
On the other hand, by performing the re-anodizing treatment (a-3) at a relatively high temperature, the arrangement of the micropores can be disturbed, and the variation in pore diameter can be made within a predetermined range. Also, the pore diameter variation can be controlled by the processing time.

  The film thickness of the anodized film formed by such re-anodizing treatment (a-3) is preferably 0.05 to 150 μm, more preferably 0.10 to 100 μm, and 0.20. More preferably, it is ˜50 μm.

Moreover, it is preferable that the average pore diameter of the micropore formed by such re-anodizing treatment (a-3) is 5 to 1000 nm, more preferably 10 to 800 nm, and 15 to 500 nm. Is particularly preferred.
Further, the micropores formed by such re-anodizing treatment (a-3) preferably have a pore diameter dispersion within 3% of the average diameter within a range of 1 μm ² , and within 2%. It is more preferable.

Moreover, it is preferable that the average pore density of the micropore formed by such re-anodizing treatment (a-3) is 1 × 10 ⁶ to 1 × 10 ¹⁰ pieces / mm ² , and 1 × 10 ⁷ to 1 More preferably, it is × 10 ⁹ pieces / mm ² .
Moreover, it is preferable that the area ratio which the micropores formed by such re-anodizing treatment (a-3) occupy is 20 to 50%.
Moreover, it is preferable that the degree of ordering defined by the above formula (i) for the micropores formed by such re-anodizing treatment (a-3) is 50% or more, and 60% or more. More preferably, it is 70% or more.

  Instead of the above-described anodizing treatment (a-1) and film removal treatment (a-2), the above-mentioned re-treatment may be performed by a physical method, a particle beam method, a block copolymer method, a resist pattern / exposure / etching method, or the like. You may form the hollow used as the starting point of the micropore production | generation by an anodizing process (a-3).

<Physical method>
For example, a method using an imprint method (a transfer method or a press patterning method in which a substrate or a roll having a protrusion is pressed against an aluminum substrate to form a concave portion) can be given. Specifically, a method of forming a depression by pressing a substrate having a plurality of protrusions on the surface thereof against the surface of the aluminum substrate can be mentioned. For example, a method described in JP-A-10-121292 can be used.
In addition, a method in which polystyrene spheres are arranged in a dense state on the surface of an aluminum substrate, SiO ₂ is deposited thereon, then the polystyrene spheres are removed, and the aluminum substrate is etched using the deposited SiO ₂ as a mask to form a recess. Also mentioned.

<Particle beam method>
The particle beam method is a method of forming a depression by irradiating the surface of an aluminum substrate with a particle beam. The particle beam method has an advantage that the position of the depression can be freely controlled.
Examples of the particle beam include a charged particle beam, a focused ion beam (FIB), and an electron beam.
As the particle beam method, for example, a method described in JP-A-2001-105400 can be used.

<Block copolymer method>
The block copolymer method is a method in which a block copolymer layer is formed on the surface of an aluminum substrate, a sea island structure is formed in the block copolymer layer by thermal annealing, and then island portions are removed to form depressions.
As a block copolymer method, the method described in Unexamined-Japanese-Patent No. 2003-129288 can be used, for example.

<Resist pattern, exposure, etching method>
In the resist pattern / exposure / etching method, the resist on the surface of the aluminum plate is exposed and developed by photolithography or electron beam lithography to form a resist pattern and then etched. In this method, a resist is provided and etched to form a recess penetrating to the surface of the aluminum substrate.

Moreover, you may form the oxide film which has a micropore on the aluminum substrate surface by performing the process of following (1)-(4) in this order as said anodizing process.
(1) Step of forming an anodic oxide film having micropores on the surface of the aluminum substrate by anodizing the surface of the aluminum substrate (2) Step of partially dissolving the anodic oxide film using acid or alkali (3) A step of growing the micropores in the depth direction by performing anodization treatment (4) A step of removing the anodized film above the inflection point of the cross-sectional shape of the micropores

<Step (1)>
In the step (1), at least one surface of the aluminum substrate is anodized to form an anodized film having micropores on the surface of the aluminum substrate.
Step (1) can be carried out in the same procedure as in the anodizing treatment (a-1).
FIG. 3 is a schematic end view of an aluminum substrate and an anodized film formed on the aluminum substrate.

  FIG. 3A shows a state in which the anodic oxide film 14a having the micropores 16a is formed on the surface of the aluminum substrate 12a by the step (1).

<Step (2)>
In step (2), the anodized film formed in step (1) is partially dissolved using acid or alkali.
Here, partially dissolving the anodic oxide film does not completely dissolve the anodic oxide film formed in the step (1), but on the aluminum substrate 12a as shown in FIG. 3B. 3A shows that the surface of the anodic oxide film 14a shown in FIG. 3A and the inside of the micropore 16a are partially dissolved so that the anodic oxide film 14b having the micropores 16b remains.
Further, the dissolution amount of the anodized film is preferably 0.001 to 50% by mass of the whole anodized film, more preferably 0.005 to 30% by mass, and 0.01 to 15% by mass. More preferably. When the dissolution amount is in the above range, the irregular part of the surface of the anodic oxide film can be dissolved to increase the regularity of the micropore array, and the anodic oxide film is formed on the bottom part of the micropore. Thus, the starting point of the anodizing treatment performed in the step (3) can be left.

  Step (2) is performed by bringing the anodized film formed on the aluminum substrate into contact with an aqueous acid solution or an aqueous alkali solution. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred.

When an acid aqueous solution is used in step (2), it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. Especially, the aqueous solution which does not contain chromic acid is preferable at the point which is excellent in safety | security. The concentration of the acid aqueous solution is preferably 0.01 to 1 mol / L. The temperature of the acid aqueous solution is preferably 25 to 60 ° C.
When an alkaline aqueous solution is used in step (2), it is preferable to use an aqueous solution of at least one alkali selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.01 to 1 mol / L. The temperature of the alkaline aqueous solution is preferably 20 to 35 ° C.
Specifically, for example, 0.5 mol / L, 40 ° C. phosphoric acid aqueous solution, 0.05 mol / L, 30 ° C. sodium hydroxide aqueous solution or 0.05 mol / L, 30 ° C. potassium hydroxide aqueous solution is suitable. Used.
The immersion time in the acid aqueous solution or alkali aqueous solution is preferably 8 to 120 minutes, more preferably 10 to 90 minutes, and still more preferably 15 to 60 minutes.

<Step (3)>
In step (3), the anodization process is again performed on the aluminum substrate in which the anodized film is partially dissolved in step (2) to grow micropores in the depth direction.
As shown in FIG. 3 (C), the oxidation reaction of the aluminum substrate 12a shown in FIG. 3 (B) proceeds by the anodic oxidation process in the step (3), and the aluminum substrate 12b is formed on the aluminum substrate 12b rather than the micropores 16b. An anodic oxide film 14c having micropores 16c grown in the depth direction is formed.

A conventionally known method can be used for the anodizing treatment, but it is preferably performed under the same conditions as the above-described anodizing treatment (a-1).
Also, a method of repeatedly turning on and off the current intermittently while keeping the DC voltage constant, and a method of repeatedly turning on and off the current while intermittently changing the DC voltage can be suitably used. According to these methods, fine micropores are generated in the anodic oxide film, which is preferable in that uniformity is improved particularly when sealing treatment is performed by electrodeposition.
In the above-described method of intermittently changing the voltage, it is preferable to decrease the voltage sequentially. As a result, the resistance of the anodized film can be lowered, and can be made uniform when the electrodeposition treatment is performed later.

  The amount of increase in the thickness of the anodized film is preferably from 0.1 to 100 μm, and more preferably from 0.5 to 50 μm. When the increase amount is in the above range, the regularity of the pore arrangement can be further increased.

<Process (4)>
In step (4), the anodized film above the inflection point 30 in the cross-sectional shape of the micropore 16c shown in FIG. As shown in FIG. 3C, the micropore formed by the self-ordering method has a substantially straight tube shape in cross section except for the upper portion of the micropore 16c. In other words, a portion (a deformed portion) 20 having a cross-sectional shape different from that of the remaining portion of the micropore 16c exists in the upper portion of the micropore 16c. In step (4), the anodized film above the inflection point 30 of the cross-sectional shape of the micropore 16c is removed in order to eliminate the deformed portion 20 existing on the upper portion of the micropore 16c.
Here, the inflection point 30 refers to a portion where the shape changes remarkably with respect to the main shape (here, a substantially straight pipe shape) formed by the cross-sectional shape of the micropore 16c. In the cross-sectional shape of 16c, it refers to a portion where the continuity of the shape is lost with respect to the main shape (substantially straight pipe shape).
By removing the anodic oxide film above the inflection point 30 of the cross-sectional shape of the micropore 16c, the entire micropore 16d has a substantially straight tube shape as shown in FIG.

  In step (4), the inflection point 30 of the cross-sectional shape of the micropore 16c is specified by photographing an FE-SEM of the anodized film 14c after the execution of the step (3) from the cross-sectional direction. The anodic oxide film above may be removed.

However, the deformed portion is generated in the micropore mainly when the anodized film 14a is newly formed on the aluminum substrate 12a as in the step (1). Therefore, in order to remove the anodic oxide film above the inflection point 30 of the cross-sectional shape of the micropore 16c and eliminate the deformed portion 20 above the micropore 16c, the anodic oxide film formed in the step (1) is used. May be removed in step (4).
As will be described later, when the step (3) and the step (4) are repeated twice or more, the deformed portion 30 is eliminated in the anodized film 14d after the step (4) is performed, and the cross-sectional shape of the micropore 16d Since the whole has a substantially straight pipe shape, a new micropore is formed above the micropore formed in step (3) (hereinafter referred to as “step (3 ′)”) following step (4). A deformed part occurs in Therefore, in the step (4) (hereinafter referred to as “step (4 ′)” in this paragraph) to be performed following the step (3 ′), a new upper portion of the micropore formed in the step (3 ′) is added. It is necessary to remove the deformed part. Therefore, in step (4 ′), it is necessary to remove the anodized film above the inflection point of the micropore formed in step (3 ′).

  In the step (4), the process for removing the anodic oxide film above the inflection point of the cross-sectional shape of the micropore 16c may be a polishing process such as mechanical polishing, chemical polishing, and electrolytic polishing. However, as in the step (2), a treatment for dissolving the anodized film using an acid or an alkali is preferable. In this case, as shown in FIG. 3D, an anodic oxide film 14d having a thickness smaller than that of the anodic oxide film 14c shown in FIG. 3C is formed.

  In the step (4), when the anodized film is partially dissolved using acid or alkali, the dissolved amount of the anodized film is not particularly limited, and the total amount of the anodized film is not limited. It is preferable that it is 0.01-30 mass%, and it is more preferable that it is 0.1-15 mass%. When the dissolution amount is in the above range, the irregular portion of the surface arrangement of the anodized film can be dissolved, and the regularity of the arrangement of the micropores can be increased. Moreover, when performing a process (3) and a process (4) repeatedly 2 times or more, the starting point of the anodizing process in the process (3) implemented next can be left.

It is preferable to repeat the step (3) and the step (4) twice because the regularity of the pore arrangement is high, more preferably 3 times or more, and more preferably 4 times or more. Is more preferable.
When the above steps are repeated twice or more, the conditions of each step (3) and step (4) may be the same or different. From the viewpoint of improving the degree of ordering, the step (3) is preferably performed by changing the voltage every time. In this case, it is more preferable to gradually change to a high voltage condition from the viewpoint of improving the degree of ordering.

In the state shown in FIG. 3D, the average pore diameter of the micropores 16d is preferably 5 to 1000 nm, more preferably 10 to 800 nm, and particularly preferably 15 to 500 nm.
Further, in the state shown in FIG. 3D, in the micropore 16d, the pore diameter dispersion is preferably within 3% of the average diameter, more preferably within 2%, in the range of 1 μm ² .
In the state shown in FIG. 3D, the average pore density of the micropores 16d is preferably 1 × 10 ⁶ to 1 × 10 ¹⁰ pieces / mm ² , and preferably 1 × 10 ⁷ to 1 × 10 ⁹ pieces / mm ^2. and more preferably in the range of mm ^2.
In the state shown in FIG. 3D, the area ratio occupied by the micropores 16d is preferably 20 to 50%.
In the state shown in FIG. 3D, the thickness of the anodic oxide film 14d is preferably 0.05 to 150 μm, more preferably 0.10 to 100 μm, and 0.20 to 50 μm. More preferably.
In the state shown in FIG. 3D, the degree of ordering defined by the above formula (i) for the micropore 16d is preferably 50% or more, more preferably 60% or more, and 70% The above is particularly preferable.

<Aluminum removal treatment>
As shown in FIG. 3D, the anodized film 14d obtained by the anodizing process is formed on the surface of the aluminum substrate 12b. In order to use the anodic oxide film 14d as the microstructure film of the present invention, it is necessary to remove the aluminum substrate 12 from the anodic oxide film 14d.

As a method of removing the aluminum substrate 12b from the anodized film 14d, there is a method of dissolving and removing the aluminum substrate 12b from the anodized film 14d.
For the dissolution of the aluminum substrate, a treatment solution that does not readily dissolve the anodic oxide film (alumina) and easily dissolves aluminum is used.
That is, the aluminum dissolution rate is 1 μm / min or more, preferably 3 μm / min or more, more preferably 5 μm / min or more, and the anodic oxide film (alumina) dissolution rate is 0.1 nm / min or less, preferably 0.05 nm / min or less. More preferably, a treatment liquid having a condition of 0.01 nm / min or less is used.
Specifically, a treatment liquid containing at least one metal compound having a lower ionization tendency than aluminum and having a pH of 4 or less and 8 or more, preferably 3 or less and 9 or more, more preferably 2 or less and 10 or more is used.

Such a treatment liquid is not particularly limited as long as it does not dissolve the anodized film (alumina) and dissolves aluminum, but for example, mercury chloride, bromine / methanol mixture, bromine / ethanol mixture, aqua regia, An aqueous solution such as a hydrochloric acid / copper chloride mixture may be used.
As a density | concentration, 0.01-10 mol / L is preferable and 0.05-5 mol / L is more preferable.
As processing temperature, -10 degreeC-80 degreeC are preferable, and 0 degreeC-60 degreeC is preferable.

  The aluminum substrate is dissolved by bringing the aluminum substrate 12b in the state shown in FIG. 3D into contact with the treatment liquid described above. The method of making it contact is not specifically limited, For example, the immersion method and the spray method are mentioned. Of these, the dipping method is preferred. The contact time at this time is preferably 10 seconds to 5 hours, and more preferably 1 minute to 3 hours.

  By the above procedure, an aluminum anodic oxide film suitable as a microstructure film in the light emitting device of the present invention can be obtained. FIG. 4 is a simplified diagram of an aluminum anodized film. In the aluminum anodic oxide film 14 shown in FIG. 4, micropores 16 having a substantially straight tube shape and arranged in a honeycomb shape are formed.

In the state shown in FIG. 4, the thickness of the anodic oxide film 14 is preferably 0.05 to 150 μm, more preferably 0.10 to 100 μm, and further preferably 0.20 to 50 μm. .
In the state shown in FIG. 4, the average pore diameter of the micropores 16 is preferably 5 to 1000 nm, more preferably 10 to 800 nm, and particularly preferably 15 to 500 nm.
In the state shown in FIG. 4, in the micropores 16, the pore diameter dispersion is preferably within 3% of the average diameter and more preferably within 2% within the range of 1 μm ² .
In the state shown in FIG. 4, the average pore density of the micropores 16 is preferably 1 × 10 ⁶ to 1 × 10 ¹⁰ pieces / mm ² , and is 1 × 10 ⁷ to 1 × 10 ⁹ pieces / mm ² . More preferably.
In the state shown in FIG. 4, the area ratio occupied by the micropores 16 is preferably 20 to 50%.
In the state shown in FIG. 4, the degree of ordering defined by the above formula (i) for the micropores 16 is preferably 50% or more, more preferably 60% or more, and 70% or more. Is particularly preferred.

  In the present invention, it is also possible to finely adjust the scattered light wavelength region by mixing another material into the microstructure film 2.

  The method of mixing the other material is not particularly limited. However, when the microstructure film 2 is an aluminum anodic oxide film, the anodizing treatment is performed by adding an additive to the anodizing treatment liquid. A method of incorporating the additive into the aluminum anodic oxide film is preferable from the viewpoint of simplicity of treatment.

  Specifically, a method is preferred in which the anodization treatment is performed with an acid or an alkali, the acid / alkali-derived anion (generally referred to as an acid radical) is taken in, and the scattering property is adjusted from the type / amount. . The type can be adjusted by the type of electrolyte and the amount by the concentration of the aqueous solution.

  In addition to the above acid radicals, a method of adding a metal compound to the electrolytic solution and containing metal ions in the aluminum anodic oxide film as described in JP-A-2008-12931 can also be applied. .

Further, by mixing a fluorescent dye that emits fluorescence by receiving light from the light emitting unit 7 in the microstructure film 2, the ultraviolet light from the light emitting unit 7 can be absorbed and the amount of light emitted in the visible light region can be improved. it can.
As the fluorescent dye mixed in the microstructure film 2, one kind of fluorescent dye may be used, and plural kinds of fluorescent dyes such as a fluorescent dye emitting red light, a fluorescent dye emitting green light, and a fluorescent dye emitting blue light are used. You may use by dispersing. In addition, as a specific example of the fluorescent dye mixed in the microstructure film 2, for example, a pyrene derivative represented by the following structural formula is preferably exemplified.

  In the above structural formula, R represents a functional group such as a hydrogen atom, a silicon group, a halogen group, or a hydrocarbon group having 1 to 30 linear, branched or cyclic structures which may have a substituent.

  In addition to the above, the fluorescent dye absorbs ultraviolet light and emits fluorescence in the visible light region. AMCA, Alexa Fluor, Marina Blue, Cascade Blue, Cascade Yellow, Pacific Blue, Hoechst, DAPI, Indo-1, Although mClB, EBFP, etc. are used suitably, it is not limited to these.

  For the purpose of improving the amount of light emitted in the visible light region, the fluorescent emission wavelength region of one or more kinds of fluorescent dyes mixed in the microstructure film 2 is preferably broad. An excimer is preferred. The wavelength region is preferably from 300 to 800 nm, more preferably from 400 to 700 nm, and particularly preferably from 450 nm to 600 nm.

The method for mixing the fluorescent dye into the fine structure film 2 is not particularly limited. However, when the fine structure film 2 is an aluminum anodic oxide film, the anodic oxidation treatment is performed with the fluorescent dye added to the anodizing treatment liquid. Therefore, the method of incorporating the fluorescent dye into the aluminum anodic oxide film is preferable from the viewpoint of controlling the amount of the fluorescent dye mixed into the microstructured film.
In addition, the method of infiltrating and drying the fluorescent dye solution into the micropores 3 of the fine structure film 2 and adsorbing or filling the pores with the pores from the viewpoint of controlling the amount of the fluorescent dye mixed into the fine structure film. Of these, the latter is more preferable because the amount of the fluorescent dye mixed into the microstructure film can be controlled more precisely.

The light-emitting element of the present invention may have a structure other than the above-described substrate, fine structure film, and light-emitting portion. As such another structure, there is a resonator structure provided for the purpose of taking out light from the light emitting layer and improving the efficiency. For example, when the light emitting element 10 shown in FIG. 1 is a bottom emission type light emitting element, a plurality of laminated films having different refractive indexes between the first electrode 4 which is a transparent electrode and the fine structure film 2 are used. A multilayer film mirror is provided, and the multilayer film mirror and the second electrode 6 function as a reflector, and light generated in the light emitting layer 5 is repeatedly reflected between them and resonated to extract light from the light emitting layer. Efficiency can be improved.
In another preferred embodiment, the first electrode 4 and the second electrode 6 function as reflectors, and light generated in the light-emitting layer 5 is repeatedly reflected between them to resonate, whereby the light from the light-emitting layer is reflected. The extraction efficiency can be improved.
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 embodiment 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 light emitting device of the present invention can be used for various display devices such as a mobile phone display, a personal digital assistant (PDA), a computer display, an automobile information display, and a TV monitor. Moreover, it can be used in a wide range of fields including general illumination in addition to display devices.

  When the light emitting device of the present invention is used as a full-color type display device, for example, as described in “Monthly Display”, September 2000, pages 33 to 37, the three primary colors (blue (B), A three-color light emitting method in which light emitting elements that emit light corresponding to green (G) and red (R) are arranged on a substrate, and a white method that separates white light emitted by a light emitting element for white light emission into three primary colors through a color filter. In addition, a color conversion method for converting blue light emission by a light emitting element for blue light emission into red (R) and green (G) through a fluorescent dye layer is known.

  In addition, by using a combination of a plurality of light emitting elements of the present invention having different emission colors, a planar light source having a desired emission color can be obtained. For example, a white light-emitting light source that combines blue and yellow light-emitting elements, a white light-emitting light source that combines blue, green, and red light-emitting elements.

  When the light emitting element of the present invention is used for a display device, the entire light emitting element may be protected by a protective insulating film. For example, when the light-emitting element is an EL element, the protective insulating film electrically insulates the EL element and the TFT from a function of reducing damage to the EL element when a TFT is formed over the EL element. It has a function. Further, the protective insulating film preferably has a function of preventing a substance that promotes element deterioration such as moisture or oxygen from entering the light emitting element.

Specific _{examples, MgO, SiO, SiO 2,} Al 2 O 3, GeO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3, TiO metal oxides such as _2, SiN _x, SiN _x O metal nitride such as _y , metal fluoride such as MgF ₂ , LiF, AlF ₃ , CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene , A copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer, and a copolymer main chain containing a cyclic structure. Fluorine copolymer, water-absorbing substance with a water absorption of 1% or more Sexual substances, and the like.

  The method for forming the protective insulating film is not particularly limited. For example, the vacuum evaporation method, the sputtering method, the reactive sputtering method, the MBE (molecular beam epitaxy) method, the cluster ion beam method, the ion plating method, the plasma polymerization method ( High frequency excitation ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, transfer method can be applied.

  When the light emitting element is an EL element, the upper electrode of the EL element and the source or drain electrode of the driving TFT need to be electrically connected. Therefore, it is necessary to form a contact hole in the protective insulating film. There is. As a method for forming the contact hole, there are a wet etching method using an etchant, a dry etching method using plasma, an etching method using a laser, and the like.

(Example 1)
In this example, a bottom emission type organic EL element having the structure shown in FIG. 1 was prepared.
(0) Glass substrate A glass substrate (TEMPAX Float, refractive index 1.48 manufactured by SHOTT Nippon) was prepared as the substrate 1. An aluminum anodic oxide film prepared in the following steps was provided as a fine structure film 2 on the surface.

(1) Metal substrate pretreatment process (electrolytic polishing)
A high-purity aluminum substrate (manufactured by Sumitomo Light Metal Co., Ltd., purity 99.99 mass%, thickness 0.4 mm) was cut so that it could be anodized in an area of 10 cm square, and then an electropolishing liquid having the following composition was used to apply voltage The electropolishing treatment was performed under the conditions of 25 V, a liquid temperature of 65 ° C., and a liquid flow rate of 3.0 m / min.
The cathode was a carbon electrode, and GP0110-30R (manufactured by Takasago Seisakusho) was used as the power source. The flow rate of the electrolytic solution was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

<Electrolytic polishing liquid composition>
-660 mL of 85% by mass phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
・ Pure water 160mL
・ Sulfuric acid 150mL
・ Ethylene glycol 30mL

(2) Anodized film formation process (anodizing treatment)
The metal substrate after the electropolishing treatment obtained above was anodized with 0.50 mol / L oxalic acid electrolyte at a voltage of 40 V, a liquid temperature of 15 ° C., and a liquid flow rate of 3.0 m / min for 1 hour. gave. Further, the anodized sample was immersed in a mixed solution of 0.5 mol / L phosphoric acid at 40 ° C. for 25 minutes for film removal treatment.
After repeating these treatments four times in this order, re-anodization treatment was performed for 4 hours with an electrolyte of 0.50 mol / L oxalic acid at a voltage of 40 V, a liquid temperature of 15 ° C., and a liquid flow rate of 3.0 m / min. Further, the micropores are arranged in the form of a straight tube and a honeycomb on the surface of the aluminum substrate by dipping for 25 minutes at 40 ° C. using a mixed aqueous solution of 0.5 mol / L phosphoric acid to perform film removal treatment. An anodized film was formed.

  In both the anodic oxidation treatment and the re-anodic oxidation treatment, the cathode was a stainless electrode, and the power supply was GP0110-30R (manufactured by Takasago Seisakusho). Further, NeoCool BD36 (manufactured by Yamato Kagaku Co.) was used as the cooling device, and Pear Stirrer PS-100 (manufactured by EYELA) was used as the stirring and heating device. The flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

(3) Aluminum substrate removal process In order to use the aluminum anodic oxide film obtained above as the fine structure film 2, the aluminum substrate was removed. Specifically, the aluminum substrate was dissolved and removed by dipping at 20 ° C. for 3 hours using a 20 mass% mercury chloride aqueous solution. FIG. 5 is a surface photograph (10,000 magnifications) after the aluminum (Al) substrate is dissolved and removed.

(4) Physical property evaluation of aluminum anodic oxide film A surface photograph (magnification 20000 times) of the aluminum anodic oxide film obtained by the procedure (3) above was taken with a FE-SEM, and the micropores existed in a 1 μm × 1 μm visual field. The dispersion of the average diameter and the pore diameter was determined by the following formula, and the dispersion / average diameter was determined.
Average diameter: μ _x = (1 / n) ΣXi
Dispersion: σ ² = (1 / n) (ΣXi ² ) −μ _x ²
Dispersion / average diameter = σ / μ _x
Here, Xi is the pore diameter of one micropore measured in the range of 1 μm ² .
Moreover, the average pore density was calculated by the following formula using 300 arbitrary micropores in a 1 μm × 1 μm visual field of a surface photograph (magnification 20000 times) by FE-SEM. In the expression, P _p represents cycle.
Average pore density (pieces / μm ² ) =
(1/2) / {P _p (μm) × P _p (μm) × √3 × (1/2)}
The results are shown below.
Average diameter: 60 nm
Dispersion: 2.8 nm
Dispersion / average diameter: 0.047
Average pore density: 1.1 × 10 ⁸ pieces / mm ²
Furthermore, the degree of ordering defined by the following formula (i) was determined using 300 arbitrary micropores in a 1 μm × 1 μm visual field of a surface photograph (magnification 20000 times) by FE-SEM. As a result, the degree of ordering was 90%.
Ordering degree (%) = B / A × 100 (i)
In the above formula (i), A represents the total number of micropores in the measurement range. B is centered on the center of gravity of one micropore, and when a circle with the shortest radius inscribed in the edge of another micropore is drawn, the center of gravity of the micropore other than the one micropore is placed inside the circle. This represents the number in the measurement range of the one micropore to be included.

(5) Electrode layer / light-emitting layer forming step After the fine structure film 2 obtained by the above procedure is placed on the glass substrate 1, it is vacuum-dried at 500 ° C. for 12 hours under a pressure of 0.01 MPa. Thus, the fine structure film 2 was fixed on the glass substrate 1.
Next, an ITO film having a thickness of 100 nm was formed on the fine structure film 2 by sputtering to form an anode as the first electrode 4. Further, α-NPD is deposited to 50 nm by vacuum vapor deposition to form a hole transport layer, and then Alq ₃ is deposited to 80 nm by vacuum vapor deposition to form an active layer. The light emitting layer 5 was formed by laminating the layers and the active layer in this order. Note that the Alq ₃ layer formed as the active layer also functions as an electron transport layer.
Finally, a magnesium-silver alloy was co-evaporated with a film thickness of 200 nm by a vacuum evaporation method at an evaporation rate ratio of 10: 1 to form a cathode as the second electrode 6. Thus, by producing the light emitting portion 7, the light emitting element 10 which is a bottom emission type organic EL element was obtained. Note that the microstructure film 2 functions as a transmission type diffraction grating portion in the organic EL element.

(Example 2)
The organic EL element of Example 2 was produced by performing the same procedure as Example 1 except having performed the following fluorescent pigment mixing process to the said microstructure film 2. FIG.

Fluorescent dye mixing step A 30 wt% MEK solution of 1,3-bis (1-pyrene) propane, which is a pyrene compound, in the micropores 3 of the microstructured film 2 obtained by the procedures of (1) to (3) above. Was dried at 120 ° C. for 60 seconds to obtain a fine structure film in which the pyrene compound was adsorbed or filled in the inner pores of the micropores, that is, a fine structure film in which the pyrene compound was mixed.

(Comparative Example 1)
The organic EL element of Comparative Example 1 in which the light emitting portion 7 is directly formed on the substrate 1 is obtained by performing the same procedure as in Example 1 except that the fine structure film 2 is not provided on the substrate 1. Produced.

A direct current voltage of 8 V was applied to each of the organic EL elements of Examples 1 and 2 and Comparative Example 1 to compare the luminance and the luminance distribution in the light emitting surface direction. As compared with the organic EL element of Comparative Example 1, the organic EL elements of Example 1 and Example 2 had a luminance of 1.40 times and 1.52 times, respectively.
In addition, the organic EL element of Comparative Example 1 had a standard deviation of luminance in the light emitting surface direction of 5.0 lux, whereas the organic EL elements of Example 1 and Example 2 each had 1.5 lux, .6 lux and more uniform brightness was obtained.

DESCRIPTION OF SYMBOLS 1 Substrate 1a, 6a Light emission surface 2 Fine structure film 2a Plane 3 Micropore 4 1st electrode 5 Light emission layer 6 2nd electrode 7 Light emission part 10 EL element 12a, 12b, 12c, 12d Aluminum substrate 14, 14a, 14b, 14c, 14d Anodized film 16, 16a, 16b, 16c, 16d Micropore 20 Deformed portion 30 Inflection point 101, 102, 104, 105, 107, 108 Micropore 103, 106, 109 yen

Claims (10)

A light-emitting element comprising a light-emitting portion and a microstructure film,
The fine structure film has a surface parallel to the light emitting surface of the light emitting element, and the surface parallel to the light emitting surface of the light emitting element has an average pore diameter of 5 to 1000 nm and an average pore density of 1 × 10 ^6. A light emitting device characterized in that micropores having a degree of ordering defined by the following formula (i) of 50% or more are formed at ˜1 × 10 ¹⁰ / mm ² .
Ordering degree (%) = B / A × 100 (i)
In the formula (i), A represents the total number of micropores in the measurement range. B is centered on the center of gravity of one micropore, and when a circle with the shortest radius inscribed in the edge of another micropore is drawn, the center of gravity of the micropore other than the one micropore is placed inside the circle. This represents the number in the measurement range of the one micropore to be included.   The light emitting element according to claim 1, wherein the light emitting part is a light emitting part of an electroluminescence (EL) element in which a light emitting layer that emits light when an electric field is applied is sandwiched between a first electrode and a second electrode. . The light emitting device further includes a substrate,
The light emitting element has a structure in which the fine structure film and the light emitting portion are provided in this order on the substrate, and a bottom emission type light emitting element in which one surface of the substrate forms a light emitting surface of the light emitting element. The light emitting device according to claim 1 or 2. The light emitting device further includes a substrate,
The light emitting element has a structure in which the light emitting portion and the fine structure film are provided in this order on the substrate, and a bottom emission type light emitting element in which one surface of the substrate forms a light emitting surface of the light emitting element. The light emitting device according to claim 1 or 2. The light emitting device further includes a substrate,
The light emitting element has a structure in which the light emitting portion and the fine structure film are provided in this order on the substrate, and a top emission type in which one surface of the fine structure forms a light emitting surface of the light emitting element. The light emitting device according to claim 1, which is a light emitting device. The light emitting device further includes a substrate,
The light emitting element has a structure in which the fine structure film and the light emitting part are provided in this order on the substrate, and a top emission type light emitting device in which one surface of the light emitting part forms a light emitting surface of the light emitting element. The light emitting device according to claim 1, wherein the light emitting device is a device.   The light emitting device according to any one of claims 1 to 6, wherein a thickness of the fine structure film is in a range of 0.05 µm to 150 µm.   The light emitting device according to claim 1, wherein the microstructure film is an aluminum anodic oxide film having micropores.   The light emitting device according to claim 1, which is an organic EL device.   The light emitting device according to claim 1, wherein the light emitting device is an LED device.