JP2011222306A - Surface light source and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface light source having high light extraction efficiency and a method for manufacturing the same.SOLUTION: A surface light source 1 comprises: a transparent substrate 10; a transparent electrode 22 provided on the transparent substrate 10; a back surface electrode 24 comprising a metal thin film spaced apart from the transparent electrode 22; and a plurality of light-emitting parts 26 provided between the transparent electrode 22 and the back surface electrode 24. The plurality of light-emitting parts 26 are spaced apart from each other in the surface direction of the surface light source 1 so that a gap 28 is formed between the plurality of light-emitting parts 26.

Description

  The present invention relates to a surface light emitter having a substantially two-dimensional emission surface using electroluminescence (hereinafter referred to as EL) and a method for manufacturing the same.

  As the surface light emitter, one using an organic EL element or an inorganic EL element is known. As a surface light emitter composed of an organic EL element, a transparent base material, a transparent electrode provided on the transparent base material, a back electrode made of a metal thin film provided apart from the transparent electrode, a transparent electrode and a back surface One having a light emitting layer including a light emitting material of an organic compound provided between electrodes is known.

  In the surface light emitter, the light emitting layer emits light by combining holes from the transparent electrode and electrons from the back electrode in the light emitting layer. The light emitted from the light emitting layer passes through the transparent electrode and the transparent substrate and is extracted from the radiation surface (the surface of the transparent substrate). Further, a part of the light emitted from the light emitting layer is reflected by the metal thin film of the back electrode, and then passes through the light emitting layer, the transparent electrode, and the transparent substrate and is extracted from the radiation surface.

  However, in this surface light emitter, light having an incident angle of light incident on a transparent electrode, a transparent substrate, external air, or the like is not less than a critical angle determined by the refractive index of the incident source material and the incident destination material. Are totally reflected at the interface between the light emitting layer and the transparent electrode, the interface between the transparent electrode and the transparent substrate, the interface between the transparent substrate and the external air (radiation surface), etc., and are confined inside the surface light emitter. Therefore, there is a problem that a part of the light cannot be extracted to the outside and the light extraction efficiency is low.

The followings have been proposed as surface light emitters that solve this problem.
A surface emitting device (patterned with a transparent grating or a back electrode patterned in a lattice pattern to cause a difference in refractive index between a portion where holes or electrons are injected into a light emitting layer and a portion where electrons are not injected into the light emitting layer) Patent Document 1).

In this surface light emitter, the total reflection at each interface is reduced by diffracting the light emitted from the light emitting layer with a diffraction grating so that the angle of incidence on the transparent electrode, the transparent substrate, and the external air is reduced. The light extraction efficiency is improved.
However, in this surface light emitter, the difference in refractive index between the portion where holes or electrons are injected into the optical layer and the portion where it is not injected is only 0.1% (paragraph [0055] of Patent Document 1), The light diffraction efficiency is negligible, and the light extraction efficiency does not improve much.

JP 2007-080890 A

  The present invention provides a surface light emitter having high light extraction efficiency and a method for manufacturing the same.

  The surface light emitter of the present invention includes a transparent substrate, a transparent electrode provided on the transparent substrate, a back electrode made of a metal thin film provided apart from the transparent electrode, the transparent electrode, and the transparent electrode. A surface light emitter having a plurality of light emitting portions provided between the light emitting portion and the back electrode, wherein the plurality of light emitting portions have a gap formed between the light emitting portions. It is characterized by being spaced apart from each other in the surface direction.

In the surface light emitter of the present invention, the transparent substrate has a plurality of protrusions on the surface, the transparent electrode is selectively formed on the protrusions, and the light emitting portion is formed on the transparent electrode. It is preferable to be formed.
The average interval between the plurality of light emitting portions is preferably 10 to 1000 nm.

The method for producing a surface light emitter according to the present invention includes the following steps (I) to (III).
(I) A step of vapor-depositing a transparent electrode material on a surface of a transparent substrate having a plurality of protrusions on the surface side, and selectively forming a transparent electrode on the protrusions.
(II) A step of forming a light emitting part on the transparent electrode by further depositing a material of the light emitting part after the step (I).
(III) A step of forming a back electrode made of a metal thin film so as to cover the light emitting portion and the gap between the light emitting portions by further depositing a metal after the step (II).

The surface light emitter of the present invention has higher light extraction efficiency than conventional surface light emitters.
According to the method for manufacturing a surface light emitter of the present invention, a surface light emitter with high light extraction efficiency can be easily manufactured.

It is sectional drawing which shows an example of the surface light-emitting body of this invention. It is sectional drawing which shows the other example of the surface light-emitting body of this invention. It is sectional drawing which shows the other example of the surface light-emitting body of this invention. It is sectional drawing which shows the other example of the surface light-emitting body of this invention. It is sectional drawing which shows the manufacturing process of the mold which has an anodized alumina on the surface. It is a block diagram which shows an example of the manufacturing apparatus of the transparent base material which has several protrusion on the surface. It is sectional drawing which shows the structure of the simulation model of a surface light-emitting body. It is a figure which shows the simulation result of the light emission intensity | strength of TE wave about the surface light-emitting body of Example 2. FIG. It is a figure which shows the simulation result of the emitted light intensity of TM wave about the surface-emitting body of Example 2. FIG. It is a figure which shows the simulation result of the emitted light intensity of TE wave about the surface light-emitting body of Example 3. FIG. It is a figure which shows the simulation result of the emitted light intensity of TM wave about the surface-emitting body of Example 3. FIG. It is a figure which shows the simulation result of the emitted light intensity of TE wave about the surface light-emitting body of the comparative example 1. It is a figure which shows the simulation result of the emitted light intensity of TM wave about the surface light-emitting body of the comparative example 1.

  In this specification, the term “transparent” means that visible light can be transmitted (having optical transparency). (Meth) acrylate means acrylate or methacrylate. Moreover, an active energy ray means visible light, an ultraviolet-ray, an electron beam, plasma, a heat ray (infrared rays etc.), etc.

<Surface emitter>
[First Embodiment]
FIG. 1 is a cross-sectional view showing an example of the surface light emitter of the present invention.
The surface light emitter 1 includes a transparent substrate 10, a plurality of transparent electrodes 22 provided on the transparent substrate 10, a back electrode 24 made of a metal thin film provided apart from the transparent electrode 22, and a transparent electrode And a plurality of light-emitting portions 26 provided between the back electrode 24 and the back electrode 24.

(Transparent substrate)
The transparent substrate 10 has a transparent support 12 and a transparent cured resin layer 14 formed on the surface of the transparent support 12.

Examples of the form of the transparent support 12 include a film, a sheet, and a plate.
The material of the transparent support 12 includes polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), acrylic resin (polymethyl methacrylate, etc.), polycarbonate, polyvinyl chloride, styrene resin (ABS resin, etc.), cellulose resin (tri- Acetyl cellulose, etc.) and glass.

  The transparent cured resin layer 14 is a film made of a cured product of an active energy ray-curable resin composition described later, and has a plurality of protrusions 16 formed by transferring pores of an anodized alumina mold described later on the surface. Have. A plurality of protrusions 16 formed by transferring pores of an anodized alumina mold described later are arranged in a plane hexagonal lattice.

  The plurality of protrusions 16 formed by transferring the pores of an anodized alumina mold, which will be described later, have a substantially conical shape, a substantially pyramidal shape, etc. A so-called moth-eye structure scattered on the surface is formed. It is known that the moth-eye structure becomes an effective antireflection means by continuously increasing the refractive index from the refractive index of air to the refractive index of the material.

  The average interval between the protrusions 16 is preferably 10 to 1000 nm, from the point that the light extraction efficiency can be sufficiently increased by the diffraction grating formed by the light emitting portion 26 and the gap 28 between the light emitting portions 26, and is preferably 50 to 1000 nm. 800 nm is more preferable.

  The average interval between the protrusions 16 is preferably not more than the wavelength of visible light, that is, not more than 400 nm from the viewpoint of suppressing reflection of light on the surface of the transparent cured resin layer 14. When the protrusions 16 are formed using an anodized alumina mold, the average distance between the protrusions 16 is more preferably 300 nm or less, and particularly preferably 150 nm or less, from the viewpoint of ease of production of the anodized alumina mold.

The average interval between the protrusions 16 is preferably 20 nm or more from the viewpoint of easy formation of the protrusions 16.
The average distance between the protrusions 16 is obtained by measuring the distance between adjacent protrusions 16 (distance from the center of the protrusion 16 to the center of the adjacent protrusion 16) by electron microscope observation and averaging these values.

The aspect ratio of the protrusion 16 (height of the protrusion 16 / average distance between the protrusions 16) is preferably 0.8 to 5, more preferably 1.2 to 4, and particularly preferably 1.5 to 3. If the aspect ratio of the protrusion 16 is 0.8 or more, the reflectance is sufficiently low. If the aspect ratio of the protrusion 16 is 5 or less, the scratch resistance of the protrusion 16 will be good.
The height of the protrusion 16 is a value obtained by measuring the distance between the top of the protrusion 16 and the bottom of the recess existing between the protrusions 16 using an electron microscope.

  The shape of the protrusion 16 is such that the cross-sectional area of the protrusion 16 in the direction orthogonal to the height direction continuously increases in the depth direction from the top, that is, the cross-sectional shape of the protrusion 16 in the height direction is triangular or trapezoidal. A shape such as a bell shape is preferable.

  The difference between the refractive index of the transparent cured resin layer 14 and the refractive index of the transparent support 12 is preferably 0.2 or less, more preferably 0.1 or less, and particularly preferably 0.05 or less. If the refractive index difference is 0.2 or less, reflection at the interface between the transparent cured resin layer 14 and the transparent support 12 is suppressed.

  The transparent substrate 10 is required to have conductivity on the surface from the viewpoint of securing conduction between a plurality of transparent electrodes 22 described later. As a method for imparting conductivity, a light-transmitting metal thin film is formed on the surface of the transparent substrate 10 (the surface of the transparent cured resin layer 14) by vacuum deposition, sputtering, ion plating, electroless plating, or the like. Method: The method etc. which mix | blend an electroconductive substance with the transparent base material 10 (transparent cured resin layer 14) are mentioned.

(Transparent electrode)
The plurality of transparent electrodes 22 are provided apart from each other in the surface direction of the surface light emitter 1 such that a gap 28 is formed between the transparent electrodes 22. Since the plurality of transparent electrodes 22 are selectively formed on the protrusions 16 formed so as to have a planar hexagonal lattice arrangement, the arrangement of the planar hexagonal lattices is almost the same as that of the protrusions 16.
The transparent electrode 22 may be an anode or a cathode. Usually, the transparent electrode 22 is an anode.

As the material of the transparent electrode 22, a metal oxide having conductivity, a metal capable of forming a light-transmitting metal thin film, an organic polymer having conductivity, or the like is used.
Examples of conductive metal oxides include indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc (IGZO) oxide, and the like. It is done.
Gold, platinum, silver, copper, aluminum etc. are mentioned as a metal which can form the metal thin film which has a light transmittance.
Examples of the organic polymer having conductivity include polyaniline, its derivatives, polythiophene, PEDOT-PSS (poly (3,4-ethylenedithiophene): poly (styrenesulfonate)), its derivatives, and the like.

The transparent electrode 22 may be a single layer or two or more layers.
The thickness of the transparent electrode 22 is preferably 10 to 1000 nm, more preferably 50 to 500 nm, from the viewpoint of achieving both light transmittance and conductivity.
The thickness of the transparent electrode 22 is obtained by measuring the thickness of the transparent electrode 22 formed on the transparent substrate using a step, surface roughness, and fine shape measuring device.

(Back electrode)
The back electrode 24 is made of a continuous metal thin film provided so as to cover the light emitting portion 26 and the gap 28 between the light emitting portions 26.
The back electrode 24 may be a cathode or an anode. Usually, the back electrode 24 is a cathode.

  Examples of the material of the back electrode 24 include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like. An alloy that combines two or more of these, metal salts such as fluoride, or one or more of these, and gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, Examples include alloys with one or more of tin. Specific examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, calcium-aluminum alloy and the like. .

The back electrode 24 may be a single layer or two or more layers.
The thickness of the back electrode 24 is preferably 5 to 1000 nm, more preferably 10 to 300 nm, from the viewpoint of conductivity and durability.
The thickness of the back electrode 24 is obtained by measuring the back electrode 24 formed on the transparent substrate with a step, surface roughness, and fine shape measuring device.

(Light emitting part)
The plurality of light emitting units 26 are provided apart from each other in the surface direction of the surface light emitter 1 such that a gap 28 is formed between the light emitting units 26. Since the plurality of light emitting portions 26 are formed on the transparent electrode 22 formed so as to have a planar hexagonal lattice arrangement, the light emitting section 26 has a planar hexagonal lattice arrangement.

When the surface light emitter 1 is an organic EL element, the light emitting unit 26 includes a light emitting material of an organic compound.
As a light-emitting material of an organic compound, a carbazole derivative (4,4′-N, N′-dicarbazole-diphenyl (hereinafter referred to as CBP)) which is a host compound of a phosphorescent compound, or an iridium complex (Tris ( 2-phenylpyridine) iridium (hereinafter referred to as Ir (ppy) ₃ ) doped (CBP: Ir (ppy) ₃ etc.); 8-hydroxyquinoline or a metal complex of its derivative (tris (8-hydroxyquinoline) ) Aluminum (hereinafter referred to as Alq ₃ ), etc.); and other known light emitting materials.
The light emitting unit 26 may include a hole transporting material, an electron transporting material, or the like in addition to the light emitting material.

The average interval between the light emitting portions 26 is preferably 10 to 1000 nm from the viewpoint that the light extraction efficiency can be sufficiently increased by the diffraction grating formed by the light emitting portions 26 and the gaps 28 between the light emitting portions 26. ˜800 nm is more preferable.
The average interval between the light emitting portions 26 is the same as the average interval between the protrusions 16 of the transparent cured resin layer 14.

The light emitting unit 26 may be a single layer or two or more layers. For example, when the surface light emitter 1 is used as white organic EL illumination, the light emitting unit 26 may have a laminated structure including a blue light emitting layer, a green light emitting layer, and a red light emitting layer.
1-100 nm is preferable and, as for the thickness of the light emission part 26, 10-50 nm is more preferable.
The thickness of the light emitting unit 26 is obtained by measuring the thickness of the light emitting unit 26 formed on the transparent substrate using a step / surface roughness / fine shape measuring device.

(Void)
The air gap 28 is a continuous space formed between the light emitting units 26 and has a lattice shape in plan view.
Air is usually present in the gap 28, but a gas other than air may be present or a vacuum may be present.

  The width of the gap 28 is determined by cross-sectional SEM observation.

(Function and effect)
In the surface light emitter 1 described above, a plurality of light emitting portions 26 are provided apart from each other in the surface direction of the surface light emitter 1 such that a gap 28 is formed between the light emitting portions 26. Therefore, a diffraction grating can be formed by the light emitting portion 26 and the gap 28. Therefore, the light emitted from the light emitting unit 26 can be diffracted by the diffraction grating, and the light extraction efficiency can be improved. Further, since the difference in refractive index between the light emitting portion 26 and the gap 28 is large, the light can be sufficiently diffracted, and the light extraction efficiency is higher than that of the conventional surface light emitter.

  Further, since the transparent substrate 10 has a plurality of protrusions 16 on the surface, the transparent electrode 22 is selectively formed on the protrusions 16, and the light emitting part 26 is formed on the transparent electrode 22, Due to the antireflection effect by the structure, reflection of light at the interface between the protrusion 16 and the gap 28 is suppressed, and the light extraction efficiency is further increased.

[Second Embodiment]
FIG. 2 is a cross-sectional view showing another example of the surface light emitter of the present invention.
The surface light emitter 2 includes a transparent substrate 12 made of a transparent support 12, a transparent electrode 22 provided on the transparent substrate, a back electrode 24 made of a metal thin film provided apart from the transparent electrode 22, It has a plurality of light emitting portions 26 provided between the transparent electrode 22 and the back electrode 24.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

(Transparent substrate)
The transparent substrate is a substrate having a flat surface, which is composed only of the transparent support 12.
Examples of the transparent support 12 are the same as those in the first embodiment.

(Transparent electrode)
The transparent electrode 22 is a continuous thin film provided on the surface of the transparent substrate 10.
Examples of the material of the transparent electrode 22 include the same materials as those in the first embodiment.
The thickness of the transparent electrode 22 is preferably in the same range as in the first embodiment.

[Third Embodiment]
FIG. 3 is a cross-sectional view showing another example of the surface light emitter of the present invention.
The surface light emitter 3 includes a transparent base material made of a transparent support 12, a plurality of transparent electrodes 22 provided on the transparent base material, and a back electrode 24 made of a metal thin film provided apart from the transparent electrode 22. And a plurality of light emitting portions 26 provided between the transparent electrode 22 and the back electrode 24.
In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

(Transparent substrate)
The transparent substrate is a substrate having a flat surface, which is composed only of the transparent support 12.
Examples of the transparent support 12 are the same as those in the first embodiment.

[Fourth Embodiment]
FIG. 4 is a cross-sectional view showing another example of the surface light emitter of the present invention.
The surface light emitter 4 includes a plurality of transparent electrodes 22, a back electrode 24 made of a metal thin film provided at a distance from the transparent electrode 22 on the surface of the transparent substrate 10 having a plurality of protrusions 16 on the surface, and a transparent electrode The plurality of light emitting unit groups 5 each having a plurality of light emitting units 26 provided between the light emitting unit 22 and the back electrode 24 are not formed with the transparent electrode 22, the light emitting unit 26, and the back electrode 24 between the light emitting unit groups 5. Are formed so as to be separated from each other in the surface direction of the surface light emitter 4.

The surface light emitter 4 is an example of an organic EL element used in an organic EL display, and each light emitting unit group 5 constitutes a red pixel, a green pixel, or a blue pixel.
In the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

[Other Embodiments]
The surface light emitter of the present invention may be any one as long as a plurality of light emitting portions are provided apart from each other in the surface direction of the surface light emitter so that a gap is formed between the light emitting portions. It is not limited to the surface light emitters 1-4 of the first to fourth embodiments.
For example, in the first to fourth embodiments, the organic compound light-emitting material is exemplified as the light-emitting material included in the light-emitting portion. However, when the surface light emitter is an inorganic EL element, an inorganic compound light-emitting material is used as the light-emitting material. That's fine.

Moreover, you may have another functional layer between a light emission part and a transparent electrode or a back electrode.
When the surface light emitter is an organic EL element, examples of other functional layers provided between the transparent electrode and the light emitting portion (light emitting layer) include a hole injection layer and a hole transport layer in this order from the transparent electrode side. .
When the surface light emitter is an organic EL element, the other functional layers provided between the light emitting portion (light emitting layer) and the back electrode are, in order from the light emitting portion (light emitting layer) side, a hole blocking layer and an electron transport layer. And an electron injection layer.

(Hole injection layer)
The hole injection layer is a layer containing a hole injection material.
Examples of the hole injection material include copper phthalocyanine (hereinafter referred to as CuPc); vanadium oxide; a conductive organic polymer; and other known hole injection materials.
1-100 nm is preferable and, as for the thickness of a positive hole injection layer, 10-50 nm is more preferable.

(Hole transport layer)
The hole transport layer is a layer containing a hole transport material.
Examples of the hole transporting material include triphenyldiamines (4,4′-bis (m-tolylphenylamino) biphenyl (hereinafter, referred to as TPD)); and other known hole transporting materials. .
1-100 nm is preferable and, as for the thickness of a positive hole injection layer, 10-50 nm is more preferable.

(Hole blocking layer)
The hole blocking layer is a layer containing a hole blocking material.
Examples of the hole blocking material include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (hereinafter referred to as BCP)); and other known hole blocking materials.
1-100 nm is preferable and, as for the thickness of a positive hole injection layer, 5-50 nm is more preferable.

(Electron transport layer)
The electron transport layer is a layer containing an electron transport material.
Examples of the electron transporting material include 8-hydroxyquinoline or a metal complex of its derivative (such as Alq ₃ ), an oxadiazole derivative; and other known electron transporting materials.
1-100 nm is preferable and, as for the thickness of an electron carrying layer, 10-50 nm is more preferable.

(Electron injection layer)
The electron injection layer is a layer containing an electron injection material.
Examples of the electron injection material include alkali metal compounds (such as lithium fluoride), alkaline earth metal compounds (such as magnesium fluoride), metals (such as strontium); and other known electron injection materials.
1-100 nm is preferable and, as for the thickness of an electron injection layer, 10-50 nm is more preferable.

  The thicknesses of the other functional layers described above are controlled by a crystal resonator in the vapor deposition apparatus after obtaining the thickness of the functional layer formed on the substrate using a step, surface roughness, and fine shape measuring device.

<Method for producing transparent substrate>
A transparent substrate having a plurality of protrusions on the surface can be produced by transferring a plurality of pores on the surface of the mold to the surface of the transparent support. Specifically, the active energy ray-curable resin composition is filled between the mold and the transparent support, and the active energy ray is irradiated and cured to form a plurality of mold pores transferred. A transparent cured resin layer having protrusions on the surface can be formed on the surface of the transparent support, and the transparent support having the transparent cured resin layer formed on the surface can be peeled off from the mold (so-called photoimprint method).

(mold)
The mold has a plurality of pores formed on the surface of a mold substrate.
Examples of the material for the mold base include metals (including those having an oxide film formed on the surface), quartz, glass, resin, ceramics, and the like.
Examples of the shape of the mold substrate include a roll shape, a circular tube shape, a flat plate shape, and a sheet shape.

As a method for producing the mold, for example, the following method (i-1) or method (i-2) may be mentioned, and the method (i-1) is possible because the area can be increased and the production is simple. Is particularly preferred.
(I-1) A method of forming anodized alumina having a plurality of pores on the surface of an aluminum substrate.
(I-2) A method of forming a plurality of pores on the surface of the mold substrate by photolithography.

As the method (i-1), a method having the following steps (a) to (f) is preferable.
(A) A step of forming an oxide film on the surface of an aluminum substrate by anodizing the aluminum substrate in an electrolytic solution under a constant voltage.
(B) A step of removing the oxide film and forming anodic oxidation pore generation points on the surface of the aluminum substrate.
(C) A step of anodizing the aluminum substrate again in the electrolytic solution to form an oxide film having pores at the pore generation points.
(D) A step of enlarging the diameter of the pores.
(E) A step of anodizing again in the electrolytic solution after the step (d).
(F) A step of repeating steps (d) and (e) to obtain a mold in which anodized alumina having a plurality of pores is formed on the surface of aluminum.

Step (a):
As shown in FIG. 5, when the aluminum substrate 30 is anodized, an oxide film 34 having pores 32 is formed.
Examples of the shape of the aluminum substrate include a roll shape, a circular tube shape, a flat plate shape, and a sheet shape.
The aluminum base material is preferably polished by mechanical polishing, feather polishing, chemical polishing, electrolytic polishing treatment (etching treatment) or the like in order to smooth the surface state. Moreover, since the oil used when processing an aluminum base material in a defined shape may adhere, it is preferable to degrease in advance before anodizing.

The purity of aluminum is preferably 99% or more, more preferably 99.5% or more, and particularly preferably 99.8% or more. When the purity of aluminum is low, when anodized, an uneven structure having a size to scatter visible light may be formed due to segregation of impurities, or the regularity of pores obtained by anodization may be lowered.
Examples of the electrolytic solution include sulfuric acid, oxalic acid, and phosphoric acid.

When using oxalic acid as electrolyte:
The concentration of oxalic acid is preferably 0.7 M or less. When the concentration of oxalic acid exceeds 0.7M, the current value becomes too high, and the surface of the oxide film may become rough.
When the formation voltage is 30 to 60 V, anodized alumina having highly regular pores with a period of 100 nm can be obtained. Regardless of whether the formation voltage is higher or lower than this range, the regularity tends to decrease.
The temperature of the electrolytic solution is preferably 60 ° C. or lower, and more preferably 45 ° C. or lower. When the temperature of the electrolytic solution exceeds 60 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken, or the surface may melt and the regularity of the pores may be disturbed.

When using sulfuric acid as the electrolyte:
The concentration of sulfuric acid is preferably 0.7M or less. If the concentration of sulfuric acid exceeds 0.7M, the current value may become too high to maintain a constant voltage.
When the formation voltage is 25 to 30 V, anodized alumina having highly regular pores with a period of 63 nm can be obtained. The regularity tends to decrease whether the formation voltage is higher or lower than this range.
The temperature of the electrolytic solution is preferably 30 ° C. or less, and more preferably 20 ° C. or less. When the temperature of the electrolytic solution exceeds 30 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken or the surface may melt and the regularity of the pores may be disturbed.

Step (b):
As shown in FIG. 5, the regularity of the pores can be improved by removing the oxide film 34 once and using it as the pore generation point 36 for anodic oxidation.

  Examples of the method for removing the oxide film include a method in which aluminum is not dissolved but is dissolved in a solution that selectively dissolves the oxide film and removed. Examples of such a solution include a chromic acid / phosphoric acid mixed solution.

Step (c):
As shown in FIG. 5, when the aluminum substrate 30 from which the oxide film has been removed is anodized again, an oxide film 34 having cylindrical pores 32 is formed.
Anodization may be performed under the same conditions as in step (a). Deeper pores can be obtained as the anodic oxidation time is lengthened.

Step (d):
As shown in FIG. 5, a process of expanding the diameter of the pores 32 (hereinafter referred to as a pore diameter expansion process) is performed. The pore diameter expansion treatment is a treatment for expanding the diameter of the pores obtained by anodic oxidation by immersing in a solution dissolving the oxide film. Examples of such a solution include a phosphoric acid aqueous solution of about 5% by mass.
The longer the pore diameter expansion processing time, the larger the pore diameter.

Step (e):
As shown in FIG. 5, when anodized again, cylindrical pores 32 having a small diameter that extend downward from the bottom of the cylindrical pores 32 are further formed.
Anodization may be performed under the same conditions as in step (a). Deeper pores can be obtained as the anodic oxidation time is lengthened.

Step (f):
As shown in FIG. 5, when the pore diameter enlargement process in the step (d) and the anodization in the step (e) are repeated, the pores 32 have a shape in which the diameter continuously decreases from the opening in the depth direction. An oxide film 34 is formed, and a mold 40 having anodized alumina (aluminum porous oxide film (alumite)) on the surface of the aluminum substrate 30 is obtained. It is preferable that the last end is step (d).

  The total number of repetitions is preferably 3 times or more, and more preferably 5 times or more. When the number of repetitions is 2 times or less, the diameter of the pores decreases discontinuously, so that the effect of reducing the reflectance of the moth-eye structure formed using anodized alumina having such pores is insufficient.

Examples of the shape of the pore 32 include a substantially conical shape, a pyramid shape, a cylindrical shape, and the like, and a cross-sectional area of the pore in a direction perpendicular to the depth direction such as a conical shape and a pyramid shape has a depth from the outermost surface. A shape that continuously decreases in the direction is preferred.
The average interval between the pores 32 is preferably not more than the wavelength of visible light, that is, not more than 400 nm. The average interval between the pores 32 is preferably 20 nm or more.
The average interval of the pores 32 was measured by measuring the distance between adjacent pores 32 (distance from the center of the pore 32 to the center of the adjacent pore 32) by electron microscope observation, and averaged these values. Is.

The aspect ratio (pore depth / pore average interval) of the pores 32 is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Particularly preferred.
The depth of the pore 32 is a value obtained by measuring the distance between the bottom of the pore 32 and the top of the convex portion existing between the pores 32 by observation with an electron microscope.

The surface of the mold on which the pores are formed may be treated with a release agent.
As the release agent, those having a functional group capable of forming a chemical bond with the anodized alumina of the aluminum substrate are preferable.

  Examples of the release agent include silicone resins, fluororesins, and fluorine compounds, and fluorine compounds having a hydrolyzable silyl group are particularly preferable. Commercially available fluorine compounds having hydrolyzable silyl groups include fluoroalkylsilane, KBM-7803 (manufactured by Shin-Etsu Chemical Co., Ltd.), MRAF (Asahi Glass), OPTOOL HD1100, HD2100 series (manufactured by Harves), OPTOOL AES4, AES6 (Manufactured by Daikin Industries), Novec EGC-1720 (manufactured by Sumitomo 3M), FS-2050 series (manufactured by Fluoro Technology), and the like.

Examples of the treatment method using a release agent include the following method (ii-1) or method (ii-2), from the point that the surface on the side where the pores of the mold are formed can be treated with the release agent without unevenness. The method (ii-1) is particularly preferable.
(Ii-1) A method of immersing a mold in a dilute solution of a release agent.
(Ii-2) A method in which a release agent or a diluted solution thereof is applied to the surface of the mold on which the pores are formed.

As the method (ii-1), a method having the following steps (g) to (l) is preferable.
(G) A step of washing the mold with water.
(H) A step of blowing air to the mold after the step (g) to remove water droplets attached to the surface of the mold.
(I) A step of immersing the mold in a diluted solution in which a fluorine compound having a hydrolyzable silyl group is diluted with a fluorine-based solvent.
(J) A step of slowly lifting the immersed mold from the solution.
(K) A step of heating and humidifying the mold after the step (j) as necessary.
(L) A step of drying the mold.

Step (g):
Since the chemicals used when forming the pores (phosphoric acid aqueous solution used for the pore diameter expansion process, etc.), impurities (dust, etc.) are attached to the mold, they are removed by washing with water.

Step (h):
If water droplets adhere to the surface of the mold, the diluted solution in step (i) deteriorates, so that air is blown onto the mold, and visible water droplets are almost removed.

Step (i):
Examples of the fluorine-based solvent for dilution include hydrofluoropolyether, perfluorohexane, perfluoromethylcyclohexane, perfluoro-1,3-dimethylcyclohexane, dichloropentafluoropropane, and the like.
As for the density | concentration of the fluorine compound which has a hydrolyzable silyl group, 0.01-0.5 mass% is preferable in a diluted solution (100 mass%).
The immersion time is preferably 1 to 30 minutes.
As for immersion temperature, 0-50 degreeC is preferable.

Step (j):
When pulling up the immersed mold from the solution, it is preferable to pull up at a constant speed using an electric puller or the like to suppress swinging during pulling. This can reduce coating unevenness.
The pulling speed is preferably 1 to 10 mm / sec.

Step (k):
The mold may be heated and humidified after the step (j). By leaving the mold under heating and humidification, the hydrolyzable silyl group of the fluorine compound (release agent) is hydrolyzed to form a silanol group, and the reaction between the silanol group and the hydroxyl group on the surface of the mold is sufficient. It progresses and the fixability of the fluorine compound is improved. As a humidifying method, a saturated salt method using a saturated salt aqueous solution, a method of heating and humidifying water, a method of spraying heated steam directly on a mold, and the like are conceivable. This step may be performed in a constant temperature and humidity chamber.
The heating temperature is preferably 30 to 150 ° C.
The humidification condition is preferably a relative humidity of 60% or more.
The standing time is preferably 10 minutes to 7 days.

Step (l):
In the step of drying the mold, the mold may be air-dried or forcibly heated and dried with a dryer or the like.
The drying temperature is preferably 30 to 150 ° C.
The drying time is preferably 5 to 300 minutes.

(Active energy ray-curable resin composition)
The active energy ray-curable resin composition contains a polymerizable compound and a polymerization initiator.
Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule.

Examples of the monomer having a radical polymerizable bond include a monofunctional monomer and a polyfunctional monomer.
Monofunctional monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, s-butyl (meth) acrylate, t- Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, Phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, allyl (meth) acrylate, 2-hydroxyethyl ( )) (Meth) acrylate derivatives such as acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate; (meth) acrylic acid, (meth) acrylonitrile; styrene, α -Styrene derivatives such as methylstyrene; (meth) acrylamide derivatives such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide and the like. These may be used alone or in combination of two or more.

  Polyfunctional monomers include ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate , Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polybutylene glycol di (Meth) acrylate, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (3- ( Ta) acryloxy-2-hydroxypropoxy) phenyl) propane, 1,2-bis (3- (meth) acryloxy-2-hydroxypropoxy) ethane, 1,4-bis (3- (meth) acryloxy-2-hydroxypropoxy) ) Butane, dimethylol tricyclodecane di (meth) acrylate, ethylene oxide adduct di (meth) acrylate of bisphenol A, propylene oxide adduct di (meth) acrylate of bisphenol A, neopentyl glycol di (meth) hydroxypivalate Bifunctional monomers such as acrylate, divinylbenzene, and methylenebisacrylamide; pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide Functional tri (meth) acrylate, trimethylolpropane propylene oxide modified triacrylate, trimethylolpropane ethylene oxide modified triacrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate and other trifunctional monomers; succinic acid / trimethylolethane / acrylic acid 4 or more functional monomers such as dipentaerystol hexa (meth) acrylate, dipentaerystol penta (meth) acrylate, ditrimethylolpropane tetraacrylate, tetramethylolmethanetetra (meth) acrylate; bifunctional or more Urethane acrylates, bifunctional or higher functional polyester acrylates, and the like. These may be used alone or in combination of two or more.

  Examples of the monomer having a cationic polymerizable bond include monomers having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group, and the like, and a monomer having an epoxy group is particularly preferable.

  Examples of the oligomer or reactive polymer include unsaturated polyesters such as a condensate of unsaturated dicarboxylic acid and polyhydric alcohol; polyester (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, epoxy (meth) Examples thereof include acrylates, urethane (meth) acrylates, cationic polymerization type epoxy compounds, homopolymers of the above-described monomers having a radical polymerizable bond in the side chain, and copolymerized polymers.

  When utilizing a photocuring reaction, examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzophenone, p-methoxybenzophenone, 2,2-diethoxy. Acetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropane- Carbonyl compounds such as 1-one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoic acid Diethoxy phosphine oxide, and the like. These may be used alone or in combination of two or more.

  When using an electron beam curing reaction, examples of the polymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t- Thioxanthone such as butylanthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl Dimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholy Phenyl) -butanone and other acetophenones; benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and other benzoin ethers; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl)- Acylphosphine oxides such as 2,4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate, 1,7-bisacridinylheptane, 9-phenyl Examples include acridine. These may be used alone or in combination of two or more.

  When utilizing a thermosetting reaction, examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxy octoate, organic peroxides such as t-butylperoxybenzoate and lauroyl peroxide; azo compounds such as azobisisobutyronitrile; N, N-dimethylaniline, N, N-dimethyl-p- Examples thereof include a redox polymerization initiator combined with an amine such as toluidine.

  As for the quantity of a polymerization initiator, 0.1-10 mass parts is preferable with respect to 100 mass parts of polymeric compounds. When the amount of the polymerization initiator is less than 0.1 parts by mass, the polymerization is difficult to proceed. When the amount of the polymerization initiator exceeds 10 parts by mass, the cured film may be colored or the mechanical strength may be lowered.

  The active energy ray-curable resin composition is made of a non-reactive polymer, an active energy ray sol-gel reactive composition, an antistatic agent, an additive such as a fluorine compound for improving antifouling properties, and fine particles as necessary. A small amount of a solvent may be contained.

Examples of non-reactive polymers include acrylic resins, styrene resins, polyurethanes, cellulose resins, polyvinyl butyral, polyesters, thermoplastic elastomers, and the like.
Examples of the active energy ray sol-gel reactive composition include alkoxysilane compounds and alkyl silicate compounds.

  Examples of the alkoxysilane compound include tetramethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-t-butoxysilane, methyltriethoxysilane, Examples include methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, trimethylpropoxysilane, and trimethylbutoxysilane.

  Examples of the alkyl silicate compound include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, n-pentyl silicate, acetyl silicate and the like.

(Manufacturing equipment)
The transparent substrate having a plurality of protrusions on the surface is manufactured as follows using, for example, a manufacturing apparatus shown in FIG.
The active energy ray-curable resin composition 18 is supplied from a tank 42 between a roll-shaped mold 40 having a plurality of pores on the surface and a strip-shaped transparent support 12 that moves along the surface of the mold 40. .

  The transparent support 12 and the active energy ray curable resin composition 18 are nipped between the mold 40 and the nip roll 46 whose nip pressure is adjusted by the pneumatic cylinder 44, and the active energy ray curable resin composition 18 is The transparent support 12 and the mold 40 are uniformly distributed, and at the same time, the pores of the mold 40 are filled.

The active energy ray curable resin composition 18 is irradiated through the transparent support 12 from the active energy ray irradiating device 48 installed below the mold 40 to cure the active energy ray curable resin composition 18. Thus, the transparent cured resin layer 14 having a plurality of protrusions 16 formed by transferring the pores on the surface of the mold 40 on the surface is formed.
The transparent substrate 10 is obtained by peeling the transparent support 12 having the transparent cured resin layer 14 formed on the surface from the mold 40 by the peeling roll 50.

As the active energy ray irradiation device 48, a high-pressure mercury lamp, a metal halide lamp, or the like is preferable. In this case, the amount of light irradiation energy is preferably 100 to 10,000 mJ / cm ² .

(Other method)
The transparent substrate having a plurality of protrusions on the surface is not limited to the transparent substrate 10 in the illustrated example. For example, the plurality of protrusions may be directly formed on the surface of the transparent support by a thermal imprint method without providing a transparent cured resin layer. Moreover, you may form using well-known methods, such as the photolithographic method, other than the imprint method. However, it is preferably formed by the optical imprint method from the viewpoint that a plurality of protrusions can be efficiently formed using the roll-shaped mold 40.

<Method for producing surface light emitter>
The surface light emitter 1 of the first embodiment can be manufactured by a method having the following steps (I) to (III).
(I) A transparent electrode 22 is selectively formed on the protrusion 16 by vapor-depositing a transparent electrode material on the surface of the transparent substrate 10 having the plurality of protrusions 16 on the surface side having the plurality of protrusions 16. Process.
(II) A step of forming a light emitting portion 26 on the transparent electrode 22 by vapor-depositing a material of the light emitting portion after the step (I).
(III) A step of forming a back electrode 24 made of a metal thin film so as to cover the light emitting portion 26 and the gap 28 between the light emitting portions 26 by further depositing a metal after the step (II).

Step (I):
Examples of the vapor deposition method include physical vapor deposition methods such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, and the sputtering method is preferable because the transparent electrode 22 can be selectively formed on the protrusions 16.

  The deposition rate (deposition) is preferably 10 nm / sec or less, more preferably 5 nm / sec or less, from the viewpoint that the transparent electrode 22 can be selectively formed on the protrusions 16. Further, the deposition rate (deposition) is preferably 0.001 nm / sec or more, more preferably 0.01 nm / sec or more, from the viewpoint of productivity.

In order to improve the adhesion between the protrusions 16 and the transparent electrode 22, the surface of the transparent substrate 10 may be subjected to UV ozone treatment, plasma treatment, corona treatment or the like before vapor deposition.
In order to remove dissolved gas and unreacted monomer contained in the transparent substrate 10, the transparent substrate 10 may be subjected to heat treatment, vacuum treatment, heat vacuum treatment, etc. before vapor deposition.

Process (II):
Examples of the vapor deposition method include physical vapor deposition methods such as vacuum vapor deposition, sputtering, and ion plating. When the material of the light emitting part is an organic compound, vacuum deposition is preferred.

  The vapor deposition rate (deposition) is preferably 10 nm / sec or less, more preferably 5 nm / sec or less, from the viewpoint that the light emitting portion 26 can be selectively formed on the transparent electrode. Further, the deposition rate (deposition) is preferably 0.1 nm / sec or more, and more preferably 0.5 nm / sec or more from the viewpoint of productivity.

  In order to improve the adhesion between the transparent electrode 22 and the light emitting portion 26, the surface of the transparent substrate 10 on which the transparent electrode 22 is formed is subjected to UV ozone treatment, plasma treatment, corona treatment, excimer lamp treatment before vapor deposition. Etc. may be applied.

  When another functional layer is provided between the light emitting unit 26 and the transparent electrode 22 or the back electrode 24, the other functional layer is the same as the light emitting unit (light emitting layer) before or after the light emitting unit (light emitting layer) is formed. The method and conditions may be used.

Step (III):
Examples of the vapor deposition method include physical vapor deposition methods such as a vacuum vapor deposition method, a sputtering method, and an ion plating method, and the vacuum vapor deposition method is preferable because it does not damage the organic layer below.

  The deposition rate (deposition) is preferably 10 nm / sec or less, more preferably 5 nm / sec or less, from the viewpoint of not damaging the lower organic layer. The deposition rate (deposition) is preferably 0.5 nm / sec or more, and more preferably 1.0 nm / sec or more from the viewpoint of easy formation of a continuous metal thin film and productivity.

(Function and effect)
In the manufacturing method of the surface light emitter 1 described above, since the transparent electrode 22 and the light emitting portion 26 are sequentially formed on the protrusions 16 by vapor deposition, surface light emission with high light extraction efficiency is achieved. The body can be easily manufactured.

(Other method)
In addition, the manufacturing method of a surface light-emitting body is not limited to the method which has process (I)-(III). For example, the light emitting portion 26 in the surface light emitter of the second embodiment may be formed by a selective vapor deposition method using a vapor deposition mask, and the transparent electrode 22 in the surface light emitter of the third embodiment is a photo You may form by the lithography method or the selective vapor deposition method.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

(Pores of anodized alumina)
A portion of the anodized alumina is shaved, platinum is vapor-deposited on the cross section for 1 minute, and a cross section is obtained using a field emission scanning electron microscope (manufactured by JEOL Ltd., JSM-7400F) at an acceleration voltage of 3.00 kV. Were observed, and the interval between the pores and the depth of the pores were measured. Each measurement was performed for 50 points, and the average value was obtained.

(Protrusion of transparent cured resin layer)
Platinum was vapor-deposited on the fracture surface of the transparent cured resin layer for 2 minutes, and the cross-section was observed in the same manner as the anodized alumina to measure the interval between the projections and the height of the projections. Each measurement was performed for 50 points, and the average value was obtained.

(Thickness of each part in the surface light emitter)
The thickness of each part (transparent electrode, light emitting layer, other functional layer, back electrode) in the surface light emitter is determined by depositing platinum on the fracture surface of the surface light emitter for 2 minutes and observing the cross section in the same manner as the anodized alumina. The thickness was measured. Each measurement was performed for 10 points, and an average value was obtained.

[Preparation Example 1]
A release agent (manufactured by Daikin Industries, Optool DSX) was diluted with an organic solvent for dilution (manufactured by Harves, Durasurf HD-ZV) to prepare a diluted solution having a release agent concentration of 0.1% by mass. .

[Production Example 1]
An aluminum plate (purity: 99.99%) of 50 mm × 50 mm × thickness 0.3 mm was electropolished in a perchloric acid / ethanol mixed solution (1/4 volume ratio).
Step (a):
The aluminum plate was anodized in a 0.3 M oxalic acid aqueous solution for 0.5 hours under the conditions of DC: 40 V and temperature: 16 ° C.
Step (b):
The aluminum plate on which the oxide film was formed was immersed in a 6% by mass phosphoric acid / 1.8% by mass chromic acid mixed aqueous solution for 6 hours to remove the oxide film, thereby forming pore generation points.
Step (c):
The aluminum plate was anodized in a 0.3 M oxalic acid aqueous solution for 30 seconds under the conditions of DC: 40 V and temperature: 16 ° C.

Step (d):
The aluminum plate on which the oxide film was formed was immersed in a 5% by mass phosphoric acid aqueous solution at 32 ° C. for 8 minutes to perform pore diameter expansion treatment.
Step (e):
The aluminum plate was anodized in a 0.3 M oxalic acid aqueous solution for 30 seconds under the conditions of DC: 40 V and temperature: 16 ° C.
Step (f):
The step (d) and the step (e) are repeated four times in total, and finally the step (d) is performed, and anodized alumina having pores having a substantially conical shape with an average interval of 100 nm and a depth of 200 nm is formed on the surface. The formed mold a was obtained.

Step (g):
The phosphoric acid aqueous solution on the surface of the mold a was washed lightly using a shower, and then the mold a was immersed in running water for 10 minutes.
Step (h):
Air was blown onto the mold a from an air gun to remove water droplets adhering to the surface of the mold a.

Step (i):
Mold a was immersed in a dilute release agent solution at room temperature for 10 minutes.
Step (j):
The mold a was slowly pulled up from the diluted solution at 3 mm / sec.
Step (k):
Using a thermo-hygrostat, the mold a was left to stand at a temperature of 60 ° C. and a relative humidity of 85% for 1 hour, and was heated and humidified.
Step (l):
The mold a was air-dried overnight to obtain a mold a treated with a release agent.

[Production Example 2]
After pouring the active energy ray-curable resin composition on the side of the mold a where the pores are formed and covering the acrylic film as a transparent support, an ultraviolet irradiation machine (high pressure mercury lamp, integrated light quantity: 400 mJ / cm ² ) Then, the active energy ray-curable resin composition was cured by irradiating ultraviolet rays to obtain a transparent cured resin layer to which the pores of the mold a were transferred. Subsequently, the transparent cured resin layer was peeled from the mold together with the transparent support, thereby obtaining a transparent substrate A having substantially conical protrusions with an average interval of 100 nm and a height of 200 nm on the surface.

[Example 1]
Step (I):
An IZO target (indium oxide: 95% by mass, zinc oxide: 5% by mass) and a transparent substrate A were set in the chamber of the sputtering apparatus.
While flowing argon gas into the chamber at 30 sccm, the pressure in the chamber at the start: 10 ⁻⁴ Pa, the pressure in the chamber at the time of deposition: 10 ⁻¹ Pa, and the deposition rate (deposition): 0.059 nm / sec. Under the conditions, IZO was vapor-deposited on the surface side of the transparent substrate having a plurality of protrusions, and a plurality of transparent electrodes having a thickness of 100 nm were selectively formed on the protrusions.

Process (II):
The transparent substrate with a transparent electrode was treated with UV ozone and then set in a chamber of a vacuum deposition apparatus.
Transparent substrate with transparent electrode under conditions of pressure in organic vapor deposition chamber: 10 ⁻⁴ Pa and vapor deposition rate (deposition): 0.5 to 2.0 nm / sec while allowing argon gas to flow into the chamber at 30 sccm On the surface side having a plurality of protrusions, CuPc (20 nm) of the hole injection layer, TPD (40 nm) of the hole transport layer, CBP: Ir (ppy) ₃ (20 nm) of the light emitting part (light emitting layer), holes BCP (10 nm) as a blocking layer and Alq ₃ (30 nm) as an electron transport layer were sequentially deposited, and a light emitting portion and other functional layers were selectively formed on the transparent electrode.

Step (III):
Furthermore, under the conditions of a pressure in the metal deposition chamber: 10 ⁻⁴ Pa and a deposition rate (deposition): 0.25 nm / sec, lithium fluoride (0.5 nm) for the electron injection layer and aluminum (100 nm) for the back electrode 1 is deposited in sequence under the conditions of deposition rate (deposition): 0.5 to 4.0 nm / sec to form a back electrode made of a metal thin film so as to cover the light emitting part and the gap between the light emitting parts. Thus, a surface light emitter having an average interval of light emitting portions of 100 nm and a gap width of 10 nm was obtained.

[Example 2]
Hereinafter, the effect of the present invention was confirmed by simulation.
The simulation model of the surface light emitter was assumed to have the structure shown in FIG. The simulation model 6 includes, in order from the top, a transparent support 12 (thickness: 698 nm, dielectric constant: 2), and a plurality of transparent electrodes 22 (interval: 100 nm, thickness: 100 nm) provided apart from each other in the plane direction. , Width: 80 nm, dielectric constant: 4.1), a plurality of light emitting portions 26 (space: 100 nm, thickness: 100 nm, width: 80 nm, dielectric constant) provided below the transparent electrode 22 and spaced apart from each other in the plane direction 2.6), a back electrode 24 (thickness: 98 nm, dielectric constant: −22.6 + 6.5i), a gap 28 (between the transparent electrode 22 and the light emitting portion 26) provided continuously in the plane direction. Width: 20 nm, dielectric constant: 1).

  As simulation software, KeyFDTD (manufactured by Science and Technology Research Laboratories) is used, and the intensity of light propagating from the transparent electrode 22 to the transparent indicator layer 12 is measured using a dipole with an oscillation frequency of 600 THz as the gray scale of the display screen Confirmed with. FIG. 8 and FIG. 9 show the results for TE waves (light whose excitation direction is parallel to the vertical direction of the paper) and TM waves (light whose excitation direction is perpendicular to the vertical direction of the paper).

Example 3
Except for changing the distance between the transparent electrode 22 and the light emitting portion 26 to 400 nm, changing the width of the transparent electrode 22 and the light emitting portion 26 to 320 nm, and changing the width of the gap 28 to 80 nm, The emission intensity was confirmed. The results for the TE wave and the TM wave are shown in FIGS.

[Comparative Example 1]
The light emission intensity was confirmed in the same manner as in Example 2 except that the transparent electrode 22 and the light emitting portion 26 were changed to a continuous layer and the void 28 was eliminated. The results for the TE wave and TM wave are shown in FIGS.

 From the above results, although there was no significant difference in the TE wave in both Examples 2 and 3 and Comparative Example 1, the light emitting part 26 and the light emitting part 26 were compared with the surface light emitter of Comparative Example 1 in which the light emitting part was a continuous layer. It was confirmed that the surface light emitters of Examples 2 and 3 in which the diffraction grating is formed with the gap 28 have high TM wave emission intensity and improved light extraction efficiency.

  The surface light emitter of the present invention is useful as an organic EL device used in organic EL lighting and organic EL displays.

DESCRIPTION OF SYMBOLS 1 Surface light-emitting body 2 Surface light-emitting body 3 Surface light-emitting body 4 Surface light-emitting body 10 Transparent base material 12 Transparent support body 14 Transparent cured resin layer 16 Protrusion 22 Transparent electrode 24 Back surface electrode 26 Light emission part 28 Space | gap

Claims (4)

A transparent substrate;
A transparent electrode provided on the transparent substrate;
A back electrode composed of a metal thin film provided apart from the transparent electrode;
A surface light emitter having a plurality of light emitting portions provided between the transparent electrode and the back electrode,
A surface light emitter in which the plurality of light emitting portions are provided apart from each other in the surface direction of the surface light emitter such that a gap is formed between the light emitting portions. The transparent substrate has a plurality of protrusions on the surface;
The transparent electrode is selectively formed on the protrusion;
The surface light emitter according to claim 1, wherein the light emitting portion is formed on the transparent electrode.   The surface light emitter according to claim 1 or 2, wherein an average interval between the plurality of light emitting portions is 10 to 1000 nm. A method for producing a surface light emitter, comprising the following steps (I) to (III).
(I) A step of vapor-depositing a transparent electrode material on a surface of a transparent substrate having a plurality of protrusions on the surface side, and selectively forming a transparent electrode on the protrusions.
(II) A step of forming a light emitting part on the transparent electrode by further depositing a material of the light emitting part after the step (I).
(III) A step of forming a back electrode made of a metal thin film so as to cover the light emitting portion and the gap between the light emitting portions by further depositing a metal after the step (II).