JP2011009450A - Light emitter of anodized alumina film, and light emitting device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bright light emitter of high luminance by improving the efficiency of light emission and light extraction.SOLUTION: For the light emitter, a light emitting material 7 which is excited by at least ultraviolet ray or blue light and emits light is filled inside a nano hole 1 of an anodized alumina film 5, the light emitting material 7 is sealed inside the nano hole 1 by a sealing member 8, and the light emitter 10 of the anodized alumina film is formed. Then, the light emitter 10 of the anodized alumina film is irradiated with the ultraviolet ray or the blue light. Also, the thickness t of the anodized alumina film 5 is suppressed to the range of 0.5-30 μm, the hole diameter (a) of the nano hole is suppressed to the range of 20-300 nm, and the pitch p of the hole of the nano hole is suppressed to the range of 50-500 nm. Also, the light emitting material 7 includes at least one of a fluorescent body or a phosphorescent body.

Description

  The present invention relates to a light emitting body of an anodized alumina film capable of high output, and a light emitting device using the light emitting body.

  A light emitting diode (hereinafter referred to as an LED) using a semiconductor light emitting element is widely used in a backlight light source of a liquid crystal panel such as a mobile phone. In particular, in recent years, the output has been increased, and application to various lighting devices such as a flashlight and indoor lighting has been put into practical use.

  As a light source color of a light source used as a backlight light source or an illumination light source, white light is generally used, but various configurations for obtaining white light have been proposed. (For example, see Patent Document 1)

The prior art disclosed in Patent Document 1 will be described with reference to FIG. FIG. 4 shows a cross-sectional view of the main part of a mounting type LED lamp rewritten so as not to depart from the gist of the invention for easy explanation.
In FIG. 4, 200 is an LED lamp. 201 is a coating portion filled with a coating material containing a photoluminescence phosphor, 202 is a light emitting element (LED chip), 203 is a conductive wire, and 204 is a housing having a recess. Reference numeral 205 denotes a terminal metal embedded in the housing 204.
In the LED lamp 200, the light emitting element 202 is fixed to the concave portion of the housing 204 via an epoxy resin containing Ag, and the n-side electrode and the p-side electrode of the light emitting element 202 are respectively connected by the conductive wires 203. The coating portion 201 is provided in the concave portion of the housing 204 so as to be connected to the metal 205 and to cover the light emitting element 202.

  In Cited Document 1, the light emitting element 202 is a gallium nitride compound semiconductor element capable of emitting blue light, and the photoluminescent phosphor is a YAG (yttrium, aluminum, garnet) fluorescent substance capable of emitting yellow light. By using the body, white light is emitted by mixing the blue light from the light emitting element 202 and the yellow light from the YAG phosphor that emits light when excited by the blue wavelength from the light emitting element 202. It is what makes it possible.

Japanese Unexamined Patent Publication No. 2000-208815 (5th page, FIG. 2)

  In general, LED lamps have the advantage of low power consumption, but on the other hand, they have the problem of low brightness compared to cold cathode tubes and incandescent lamps. Therefore, attempts have been made to increase the luminance by increasing the number of LED lamps or applying a high pulse current.

  The configuration of the LED lamp 200 described in the cited document 1 has a configuration in which a coating portion 201 is provided so as to cover a light emitting element 202 and a conductive wire, and the coating portion 201 is fluorescent on a coating material such as a resin. It has a distributed structure.

In such a configuration, the thickness of the coating portion 201 in which the phosphor is dispersed is increased, and the light extraction area is limited only to the upper surface side of the coating portion 201.
Therefore, in the process in which the blue light of the light emitting element 202 and the yellow light of the phosphor are emitted from the upper surface of the coating unit 201 by repeating scanning in the coating unit 201, coating with a thick resin or the like is performed. A lot of light that is absorbed by the material and disappears also appears.
Then, the brightness is lowered as a whole, leading to a decrease in light emission efficiency and a decrease in light extraction efficiency.
Further, when a high pulse current is applied to the light emitting element 202, the heat generation temperature becomes high, but there is a problem that it is thermally conducted to the coating part 201 and deteriorates the performance of the phosphor.
The present invention has been made in view of the above-described problems, and improves luminous efficiency and light extraction efficiency to obtain a bright and bright illuminant, and to improve performance of the illuminant by suppressing performance deterioration. It is for the purpose.

  As means for solving the above-mentioned problems, the light emitter of the present invention is a light emitter using an anodized alumina film, which is excited by at least ultraviolet light or blue light in a nanohole of the anodized alumina film. The luminescent material is filled, and the luminescent material is sealed in the nanohole by a sealing member.

The anodized alumina film is an artificially formed porous oxide film by electrolytic treatment (alumite treatment) of aluminum with an anode, and there are several nanoholes having cylindrical micropores with a diameter of several nanometers to several hundred nanometers. It is a film made of porous Al ₂ O ₃ formed at a pitch interval of 10 nm to several 100 nm. The columnar partition wall portion (hereinafter referred to as an alumina layer) sandwiched between adjacent nanoholes is transparent and has a very high light transmittance.

The phosphor formed in the nanohole of the anodized alumina film having such a structure is filled with a luminescent material that emits light by being excited with ultraviolet light or blue light, and sealed with a sealing member. When irradiated with light, the luminescent material emits light.
The light emitted from the luminescent material is emitted from the wall surface of the nanohole to the outside, that is, emitted from the nanohole to the alumina layer, and then emitted from the alumina layer to the outside. Of course, the light is emitted from the nanohole filled with the luminescent material.
Since there are an infinite number of nanoholes in the anodized alumina film, the total area of the wall surfaces of the nanoholes occupies a very large area. For this reason, the light extraction area from the wall surface of the nanohole becomes very wide, and the amount of light emitted from the wall surface of the nanohole increases remarkably. And it permeate | transmits an alumina layer and radiate | emits outside. In this case, the efficiency of extracting light emitted from the luminescent material is increased and the brightness is remarkably increased.
Further, since the ultraviolet light or blue light passes through the alumina layer and enters the light emitting material, the light emission efficiency can be increased.
As a result, the light emission efficiency and the light extraction efficiency are improved and the light emission luminance of the light emitter is significantly increased.

  In addition, the phosphor of the present invention is characterized in that the anodized alumina film has a thickness of 0.5 to 30 μm, the hole diameter of nanoholes is 20 to 300 nm, and the pitch of holes is 50 to 500 nm.

The thickness of the anodized alumina film is preferably in the range of 0.5 to 30 μm. If the thickness is smaller than 0.5 μm, the amount of emitted light of the excitation light of ultraviolet light or blue light increases, the amount of emitted light of the light emitted by the luminescent material is relatively reduced, and the brightness and hue of the emitted color change. End up. For example, when blue light is selected as the excitation light and a YAG phosphor described later is selected and combined as the luminescent material, blue light appears strongly and becomes bluish white light. In addition, the amount of emitted light is reduced and the brightness is reduced.
On the other hand, if the thickness is larger than 30 μm, the amount of light to be extinguished increases, and a portion where ultraviolet light or blue light excitation light does not reach sufficiently appears in the luminescent material, resulting in a decrease in light emission luminance. In addition, it takes a long time for the anodic oxidation treatment, resulting in an increase in cost.

  The hole diameter of the nanohole is preferably in the range of 20 to 300 nm. The pore diameter is determined by conditions such as the acid concentration, voltage, and time of anodization, but it is difficult to make it smaller than 20 nm. On the other hand, when the pore diameter is larger than 300 nm, the thickness of the partition wall (hereinafter referred to as the width of the alumina layer) becomes thin, and the mechanical strength of the alumina layer becomes weak. That is, the strength as a film cannot be maintained.

  The nanohole pitch is preferably 50 to 500 nm. The pitch is set in relation to the hole diameter of the nanohole, but if the pitch is made smaller than 50 nm, the width of the alumina layer becomes small and the mechanical strength of the alumina layer cannot be obtained. On the other hand, when the thickness is larger than 500 nm, light unevenness, that is, light emission color unevenness becomes visible to the naked eye.

  The thickness of the anodized alumina film, the hole diameter of the nanoholes, and the pitch of the holes interact with each other and affect the light emission luminance and the light emission color. The thickness of the anodized alumina film, the hole diameter of the nanoholes, and the pitch of the holes are preferably set appropriately within the above numerical range in consideration of the light emission luminance and the light emission color.

  In addition, the luminescent material of the present invention is characterized in that the luminescent material comprises at least one of a phosphor and a phosphor.

  A phosphor or phosphor that emits long-wavelength light when excited with ultraviolet light or blue light is preferred. Since such phosphors and phosphors have excellent wavelength conversion efficiency, the amount of emitted light can be increased. In addition, various emission colors can be obtained.

  The phosphor of the present invention is characterized in that the phosphor is a YAG phosphor.

  The YAG phosphor emits yellow light when excited by blue light. Then, blue light and yellow light are mixed to obtain white light.

  The light-emitting device of the present invention is characterized by having the above-described light emitting body of the anodized alumina film and a light source that emits ultraviolet light or blue light.

  By adopting such a configuration, a light emitting device with high emission luminance can be obtained, and a light emitting device capable of obtaining various emission colors can be obtained. Further, the integration of the light emitting body and light source of the anodized alumina film produces effects such as ease of handling.

  The light emitting device of the present invention is characterized in that a light emitting body of an anodized alumina film is disposed on the light emitting side of a light source.

  Under this configuration, light from the light source is directly incident on the light emitter of the anodized alumina film. Therefore, the utilization efficiency of the light source light is increased, the wavelength conversion efficiency of the light emitter is also increased, and a light emitting device with high luminance can be obtained.

  The light-emitting device of the present invention is characterized by having an air layer between the light source and the light-emitting body of the anodized alumina film.

  By having an air layer, the heat conduction to the light emitter at the heat generation temperature of the light source can be kept low. And the performance degradation of a luminescent substance can be suppressed. Produces long life effect.

  The light emitting device of the present invention is characterized in that the light source is an LED.

  By using the LED, a small light-emitting device with high luminance can be obtained.

  Under the present invention, a bright and high-luminance illuminator and a light-emitting device can be obtained. Further, it is possible to obtain the effect of extending the life by suppressing the deterioration of the performance of the luminescent material.

It is the partial perspective view and sectional view which showed typically the light-emitting body of the anodized alumina film | membrane which concerns on 1st Embodiment of this invention. It is explanatory drawing shown typically which demonstrates the effect of the light-emitting body of the anodized alumina film | membrane shown in FIG. It is principal part sectional drawing which showed typically the light-emitting device using the light-emitting body of the anodized alumina film | membrane which concerns on 2nd Embodiment of this invention. It is principal part sectional drawing of the mounting type LED lamp described in patent document 1. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, the light emitting body of the anodized alumina film according to the first embodiment will be described with reference to FIGS. 1 is a partial perspective view and a cross-sectional view schematically showing a light emitting body of an anodized alumina film according to the first embodiment of the present invention. FIG. 1 (a) is a perspective view thereof, FIG. b) is a sectional view. FIG. 2 is an explanatory view schematically showing the function and effect of the light emitting body of the anodized alumina film shown in FIG.

In FIG. 1, reference numeral 1 denotes a nanohole formed as a cylindrical fine hole formed by subjecting an Al material to anodization (alumite) treatment. Reference numeral 2 denotes an alumina layer made of Al ₂ O ₃ formed on the outer periphery of the nanohole 1. The alumina layer 2 has transparency and high light transmittance. Reference numeral 5 denotes an anodized alumina film. Reference numeral 6 denotes a light emitting layer filled in the nanohole 1, and 7 denotes a light emitting substance in the light emitting layer 6. 8 is a sealing member that seals both sides of the nanohole 1, and is provided on both sides of the nanohole 1, that is, on the upper and lower surfaces of the anodized alumina film 5. The light emitting layer 6 containing the light emitting substance 7 is sealed in the nanohole 1. It has stopped. Reference numeral 10 denotes a light emitter of an anodized alumina film.

The anodized alumina film 5 includes a plurality of nanoholes 1 and an alumina layer 2 made of Al ₂ O ₃ formed on the outer periphery of the nanoholes 1.
Further, the phosphor 10 of the anodized alumina film is formed by filling the nanohole 1 of the anodized alumina film 5 with the light emitting layer 6 containing the luminescent material 7 and providing the sealing members 8 on the upper and lower surfaces of the anodized alumina film. Thus, the light emitting layer 6 is sealed.

The anodized alumina film 5 is produced by anodizing a high-purity Al plate in an acidic electrolytic solution such as sulfuric acid, oxalic acid, phosphoric acid or the like, thereby generating nanoholes 1 and an alumina layer 2. After the generation, a bottom layer called a barrier layer remains below the nanohole 1, but by removing the bottom layer by etching, an anodized alumina film in which the nanohole 1 serving as a through hole shown in FIG. 1 is formed. 5 is obtained.
The hole diameter a and pitch p of the nanohole 1 and the depth of the nanohole 1 (the depth of the nanohole 1 corresponds to the thickness t of the anodized alumina film 5) are the concentration, temperature, and anode of the acidic electrolytic solution used for anodization. Control is possible according to the oxidation voltage application method, voltage value, time, and other processing conditions. By regulating these processing conditions, the required hole diameter a, pitch p, depth (thickness t), and array structure are obtained. be able to.

  Moreover, the hole diameter a can be increased by performing a bore-wide treatment. For example, the hole diameter can be increased by immersion in a phosphoric acid solution. Therefore, it is possible to control the size of the desired hole diameter to be widened by managing the immersion time and the like.

Further, the nanoholes 1 are preferably arranged in a honeycomb shape (honeycomb shape or regular hexagonal shape), and the pitches p of the adjacent nanoholes 1 are all equal, and between the adjacent nanoholes 1. All the widths of the alumina layer 2 are also uniform.
In the first embodiment, the hole diameters a of the nanoholes 1 are all the same, the nanoholes 1 are arranged in a honeycomb shape, and the pitches p of adjacent nanoholes 1 are arranged at the same interval.

  Here, it is preferable that the hole diameter of the nanoholes 1 is 20 to 300 nm, the pitch p is 50 to 500 nm, and the thickness t of the anodized alumina film 5 is 0.5 to 30 μm.

  The hole diameter of the nanohole 1 is preferably in the range of 20 to 300 nm. The pore diameter is determined by conditions such as the acid concentration, voltage, and time of anodization, but it is difficult to make it smaller than 20 nm. On the other hand, if the pore diameter is larger than 300 nm, the width of the alumina layer becomes smaller (thinner) and the mechanical strength of the alumina layer becomes weaker. That is, the strength as a film cannot be maintained.

  The pitch of the nanoholes 1 is preferably 50 to 500 nm. The pitch is set in relation to the hole diameter of the nanohole 1, but if the pitch is made smaller than 50 nm, the width of the alumina layer becomes small and the mechanical strength of the alumina layer cannot be obtained. On the other hand, when the thickness is larger than 500 nm, light unevenness, that is, light emission color unevenness becomes visible to the naked eye.

The thickness of the anodized alumina film 5 is preferably in the range of 0.5 to 30 μm. If the thickness is smaller than 0.5 μm, the amount of emitted light of the excitation light of ultraviolet light or blue light increases, the amount of emitted light of the light emitted by the luminescent material is relatively reduced, and the brightness and hue of the emitted color change. End up. For example, when blue light is selected as the excitation light and a YAG phosphor described later is selected and combined as the luminescent material, blue light appears strongly and becomes bluish white light. In addition, the amount of emitted light is reduced and the brightness is reduced.
Further, if the thickness is larger than 30 μm, the amount of light to be extinguished increases, and a portion where the excitation light of ultraviolet light or blue light does not reach sufficiently appears in the luminescent material, resulting in poor luminous efficiency and luminous luminance. It begins to decline.

  The hole diameter and hole pitch of the nanohole 1 and the thickness of the anodized alumina film are related to each other and affect the light emission luminance and the light emission color. It is desirable that the nanohole hole diameter, the hole pitch, and the thickness of the anodized alumina film are appropriately set within the above numerical range in consideration of the light emission luminance and the light emission color.

Next, as the light emitting material 7 constituting the light emitting layer 6 of the light emitting body 10 of the anodized alumina film, a phosphor or phosphor that emits long wavelength light by being excited with a short wavelength such as ultraviolet light or blue light is used. It is done.
Such phosphor materials include inorganic phosphors such as aluminate phosphors, phosphate phosphors, silicate phosphors, perylene phosphors, allylsulfonamide / melamine formaldehyde co-condensation dyes, and the like. Organic phosphor etc. are mentioned.

Among these, an aluminate phosphor which is a YAG (yttrium / aluminum / garnet) phosphor is suitable as the inorganic phosphor because it can be used for a long period of time.
The YAG phosphor contains yttrium (Y) and aluminum (Al), and is activated (activated) with cerium (Se), and has a chemical formula of Y ₃ Al ₅ O ₁₂ . This YAG phosphor is excited by blue light and emits yellow-green light having a peak wavelength of 560 nm. And white light can be obtained by the mixed color of this yellow green and blue light.
In addition, perylene-based phosphors are preferred as organic phosphors.

  In addition, there are phosphors with various emission colors such as red phosphor, green phosphor, orange phosphor, and blue phosphor. It is preferable to select.

  The luminescent material 7 constitutes the luminescent layer 6 and is filled in the nanoholes 1 that are fine holes. Therefore, when an inorganic phosphor is used for the luminescent material 7, it is used as a nanoparticulate powder in a range that can be sufficiently filled in the nanohole 1.

One method for filling the nanohole 1 with the luminescent substance 7 is to immerse the anodized alumina film 5 in a solution obtained by mixing the nanoparticle powder in a low boiling point solvent and fill the nanohole 1 with the solution containing the nanoparticle powder. To do. Thereafter, the luminescent material 7 can be filled in the nanoholes 1 by heat treatment to evaporate the solvent.
When this method is adopted, the light emitting layer 6 is composed only of the light emitting material 7 which is a phosphor of nano-particle powder.

Among the above filling methods, it is also possible to add a transparent curable resin. For example, by immersing the anodized alumina film 5 in a solution in which a thermosetting resin, nano fine particle powder, and a solvent are mixed to fill the nanohole 1, heat treatment is performed to evaporate the solvent and cure the resin. The luminescent material 7 dispersed in the resin is filled.
In this case, the light emitting layer 6 is composed of a resin and a light emitting material 7.

  As a method for filling the luminescent material 7, methods other than the dipping and filling method include methods such as an electrodeposition method and a CVD method.

The light emitting layer 6 may contain a light diffusing agent in addition to the light emitting substance 7. Examples of the diffusing agent include barium titanate (BaTiO ₃ ), titanium oxide (TiO ₂ ), alumina (Al ₂ O ₃ ), and silicon oxide (SiO ₂ ). Any of these diffusing agents is contained as fine particle powder.
By including a diffusing agent in the light emitting layer 6, the light emitted from the light emitting material 7 is diffused in the light emitting layer 6, and the amount of light emitted from the wall surface of the nanohole 1 to the alumina layer 2 increases.

Further, the light emitting layer 6 can contain a colorant. Since there are various color pigments as the colorant, an appropriate pigment may be used according to the required specifications.
By incorporating a colorant, it is possible to adjust to a desired emission color.

Next, the sealing member 8 is formed of a transparent and insulating resin film or a transparent and insulating metal oxide (for example, SiO ₂ ) film.
The resin film can be formed by a method such as a spin coat method, a roll coater method, or a coating method, and the metal oxide film can be formed by a method such as a vacuum evaporation method or a sputtering method.

  As described above, when the light emitting layer 6 is composed of the cured resin and the light emitting substance 7, the cured resin itself can serve as a sealing member, so that it is newly sealed. There is no need to provide a stop member, and the resin serves as an alternative to the sealing member. Of course, there is no problem even if a new sealing member is provided.

Next, the operation and effect of the light emitting body 10 of the anodized alumina film of the first embodiment will be described with reference to FIG.
In FIG. 2, P is excitation light such as ultraviolet light or blue light, and is irradiated in the direction of the arrow, that is, toward the light emitting body 10 of the anodized alumina film. Q represents the light emitted from the luminescent substance 7 which is an inorganic phosphor when excited by the excitation light P and undergoes wavelength conversion. For ease of viewing, only three light lines are representatively represented.

In the light emitting layer 6 in the nanohole 1, the light Q emitted from the light emitting material 7 is excited by the excitation light P and is emitted in all directions. Since the nanohole 1 is a nano-hole, the amount of light that disappears in the light emitting layer 6 is small, and a large amount of the emitted light passes through the wall surface of the nanohole 1 and enters the alumina layer 2.
Since the alumina layer 2 is transparent and has a very high light transmittance, the amount of light that disappears in the alumina layer 2 is very small. Therefore, a large amount of emitted light incident on the alumina layer 2 passes through the alumina layer 2 and is emitted as light Q to the outside (in FIG. 2, the outside on the upper surface side of the light emitting body 10 of the anodized alumina film). It becomes like this. Of course, light incident on other adjacent nanoholes 1 also appears, but the light passes through the nanoholes 1 and eventually enters the alumina layer 2.
Further, the emitted light Q also appears as light that passes through the light emitting layer 6 and is emitted outside without entering the alumina layer 2.

As shown in FIG. 2, the excitation light P incident on the luminescent material 7 of the light emitting layer 6 is directly incident on the light emitting layer 6 from the lower surface side of the light emitting body 10 having an anodic alumina film thickness, and from the lower surface side. There is excitation light P that passes through the alumina layer 2 and enters the light emitting layer 6.
Since the alumina layer 2 has the entire circumference of the light emitting layer 6 of the nanohole 1, the amount of the excitation light P that is transmitted through the alumina layer 2 and incident on the light emitting layer 6 is large, and the inner side (here In the figure, the back means that the light emitting layer 6 is incident on the lower surface of the light emitter 10 as viewed from the incident portion on the lower surface of the light emitter 10, and indicates the portion closer to the upper surface). Excitation light P is incident on the light emitting layer 6 over the entire thickness of the light emitting layer 6. Then, the luminescent material 7 is excited.
For this reason, many light emitting substances 7 contained in the light emitting layer 6 are excited to emit light. As a result, the luminous efficiency is remarkably increased, and light emitted to the outside is emitted through the alumina layer 2 and the light emitting layer 6.

  Further, it also appears that the excitation light P passes through the alumina layer 2 as it is and is emitted to the outside. Then, the excitation light P and the emitted light Q are mixed inside and outside the alumina layer 2.

Here, the area of the wall surface of the nanohole 1 greatly affects the amount of extracted light Q, and greatly affects the luminance of light emission. The area of the wall surface of the nanohole 1 is represented by the hole diameter a × π × thickness t of the anodized alumina film. However, if the wall surface area is small, the amount of emitted light is small and the amount of extracted light is reduced. , The emission luminance is lowered. On the other hand, when the area is large, the amount of extracted light increases and the light emission luminance is increased.
In the present invention, the thickness t of the anodized alumina film is set in the range of 0.5 to 30 μm, and the minimum value of the thickness t is limited to 0.5 μm. This is because when the wall surface area of the nanohole 1 is small, the emitted light quantity of the light Q emitted by the luminescent material, that is, the extracted light quantity of the emitted light Q is reduced, and the emission luminance is lowered. At the same time, the amount of light emitted from the excitation light increases and the color of the emitted light changes.

There are two methods for increasing the area of the wall surface: a method of increasing the hole diameter a of the nanoholes and a method of increasing the thickness t of the anodized alumina film. In the present invention, the hole diameter a is restricted to a range of 20 to 300 nm. In particular, the thickness t of the anodized alumina film is set to 0.5 to 30 μm, which is nearly 100 times as thick as the hole diameter a, to increase the area of the wall surface.
The maximum value of the thickness t is limited to 30 μm. The reason for this is that when the thickness t is larger than 30 μm, the excitation light P does not reach the luminescent material 7 in the portion on the upper surface side of the luminescent material 10 of the anodized alumina film, causing problems such as a decrease in luminous efficiency. This is because the emission luminance is reduced. For this reason, the maximum thickness t is limited to 30 μm.

By setting the thickness t of the anodized alumina film to be approximately 100 times larger than the hole diameter a, the amount of extracted light is increased and the high emission luminance is obtained.
Note that the method of increasing the hole diameter a of the nanoholes does not necessarily improve the light emission efficiency because much light disappears in the light emitting layer 6.

Further, the nanoholes 1 are arranged in a honeycomb shape, and the intervals of the pitches p of the adjacent nanoholes 1 are set to be equal intervals. As a result, the widths of the alumina layers 2 around the respective nanoholes 1 are all the same and uniform.
For this reason, there is no bias in the amount of emitted light emitted from each alumina layer 2 to the outside, and a uniform amount of emitted light can be obtained. This is because the mixed light of the excitation light P and the emitted light Q is emitted from each alumina layer 2 under a uniform light amount, and the unevenness in the emitted light amount is eliminated, and uneven brightness is suppressed. .

  Further, even when a mixed emission color is obtained by mixing the excitation light P and the emitted light Q, uneven color of the mixed emission color is suppressed.

For example, when the YAG phosphor that uses blue light as the excitation light P and the luminescent material 7 emits yellow-green light having a peak wavelength of 560 nm when excited by the blue light, white light is generated by mixing blue light and yellow-green light. Is obtained.
By using the YAG phosphor to form the light emitting body 10 of the anodized alumina film, white light with no color unevenness can be obtained and white light with high luminance can be obtained.

As described above, by improving the light emission efficiency and the light extraction efficiency, the light emission luminance can be improved by 2 to 3 times as compared with the configuration described in the prior art. In addition, an effect of suppressing unevenness in the emission color can be obtained.
Further, by limiting the hole diameter a of the nanohole 1 to max 300 nm and the hole pitch p to min 50 nm, the effect of ensuring the mechanical strength of the anodized alumina film 5 can be obtained.
Further, as an additional effect, it is an effect that the thickness can be reduced. A thin sheet can be formed, and the sheet can be cut into a required size according to the application, thereby greatly improving convenience.

The phosphor 10 of the anodized alumina film shown in FIG. 1 has a structure in which both the upper and lower surfaces are sealed by the sealing member 8, but one surface remains with the barrier layer remaining. The surface on the opening side of the other nanohole 1 may be sealed with a sealing member 8.
Since the barrier layer is transparent and has high light transmittance, the same effect as that of the structure shown in FIG. In addition, this structure can reduce the manufacturing cost because the sealing member only needs to be formed on one side.

[Second Embodiment]
Next, as a second embodiment, a light emitting device using a light emitting body of an anodized alumina film will be described with reference to FIG. FIG. 3 is a cross-sectional view schematically showing a main part of a light emitting device using a light emitting body of an anodized alumina film according to the second embodiment of the present invention. Note that components having the same specifications as the components in the first embodiment will be described with the same reference numerals.

  In FIG. 3, 1 is a nanohole of an anodized alumina film, 2 is an alumina layer of an anodized alumina film, and 5 is an anodized alumina film. Reference numeral 6 denotes a light emitting layer filled in the nanohole 1 of the anodized alumina film 5, 7 denotes a light emitting substance contained in the light emitting layer 6, and 8 denotes a sealing member for sealing the light emitting layer 6. Reference numeral 10 denotes a light emitter of an anodized alumina film. The configuration of the light emitting body 10 of the anodized alumina film uses the same components as the components of the first embodiment described above, and therefore detailed description thereof is omitted.

  Next, 21 is a base, and 22 and 23 are electrodes, which serve to turn on the light source by supplying current. Reference numeral 25 denotes a light source, and 24 denotes a joining member that connects the light source 25 and the electrodes 22 and 23. Reference numeral 27 denotes a frame, 28 denotes an air layer, and 30 denotes a light emitting device.

  In the light emitting device 30, a light source 25 is mounted on a base 21 provided with a pair of electrodes 22 and 23 via a bonding member 24, an outer peripheral region of the light source 25 is surrounded by a frame 27, and an anodized alumina film is formed on the frame 27. It has a structure in which the light emitter 10 is disposed. And it has the structure where the irradiation light of the light source 25 is irradiated toward the light-emitting body 10 of an anodized alumina film.

  Hereinafter, the specification of the light-emitting device of 2nd Embodiment is demonstrated. The light emitting device 30 according to the second embodiment uses a blue light emitting LED as the light source 25. Further, the luminescent material 7 of the luminescent material 10 of the anodized alumina film is made of a YAG phosphor.

A typical blue light emitting LED includes a pn-junction gallium nitride (GaN) compound semiconductor. This has a peak wavelength near the emission wavelength of 430 nm, and also has an emission peak in the ultraviolet region near 370 nm.
The YAG phosphor contains yttrium (Y) and aluminum (Al), and is activated by cerium (Se). It is excited by blue light and emits yellowish green with a peak wavelength of 560 nm. To do. The yellow-green light and the blue light from the LED are mixed to obtain white light.

The base 21 is made of an insulating resin, ceramic, or the like. Since the light source 25 is mounted, it is strong in strength.
Further, the pair of electrodes 22 and 23 are made of a metal such as copper or gold having good conductivity.
Note that the pair of electrodes 22 and 23 shown in FIG. 3 have a U-shape, but this is a mounting-type lamp unit that is attached to the motherboard. However, the base 21 and the pair of electrodes 22 and 23 may be the mother board itself or may have other shapes.

As the bonding member 24, a member having good conductivity is used. A metal material having a low melting point such as gold or lead, a conductive adhesive, or the like is used.
The connection structure between the LED light source 25 and the electrodes 22 and 23 shown in FIG. 3 has a flip chip structure. However, the connection structure is not limited to the flip chip structure. For example, the conductivity used in the prior art is used. There is no problem even if it is structured to connect with wires.

The frame 27 is provided to prevent the light from the light source 25 from escaping in the horizontal direction in the figure, and the inner wall surface or the outer wall surface of the frame 27 has a reflecting means and has a reflecting function. It is made of resin or ceramic.
Since the reflecting means is provided on the inner wall surface or the outer wall surface, the light incident on the frame 27 by the light from the light source 25 is reflected toward the light emitter 10 of the anodized alumina film.
Further, the light emitting body 10 of an anodized alumina film is fixed to the upper surface of the frame 27 with an adhesive.
In FIG. 3, the shape of the frame 27 is such that the inner wall surface stands vertically, but the inner wall surface has a shape having an inclined surface, and the reflected light from the inclined surface of the frame 27 is directly reflected. You may make it easy to inject into the light-emitting body 10 of an anodized alumina film | membrane.

The air layer 28 is provided to suppress the heat generated from the light source 25 from being directly transmitted to the light emitting body 10 of the anodized alumina film. By providing the air layer 28, the temperature rise of the light emitting body 10 of the anodized alumina film is suppressed, and the performance deterioration of the light emitting material 7 is prevented.
In the case where the light source 25 is used in a state where the heat generation is low, the air layer 28 may not be specially provided, and a structure in which a transparent resin is embedded in the frame 27 may be used.

In the second embodiment, a blue light emitting LED is used as the light source 25 and a white light emitting light emitting device is configured using a YAG phosphor as the light emitting material 7, but the light source 25 is a blue light emitting LED. However, a lamp that emits ultraviolet light or blue light is used. Examples of such lamps include mercury lamps and LED lamps. It is also possible to use electroluminescence as a light source.
Further, the luminescent material 7 is not limited to a YAG phosphor, and a phosphor that emits light when excited by ultraviolet light or blue light is used. An appropriate phosphor may be selected according to the specification of the emission color to be obtained.

The light-emitting device 30 having the above configuration is a light-emitting device in which the light-emitting body 10 made of an anodized alumina film and the light source 25 are integrated. Therefore, handling of the light emitting device is facilitated, and effects such as ease of work in assembling into the device are obtained.
Further, as described in detail in the first embodiment, a light emitting device with high luminance can be obtained by the action of the light emitting body of the anodized alumina film.
Even when a light source with high heat generation is used, the heat conduction of the anodized alumina film to the light emitter is suppressed to prevent the deterioration of the performance of the light emitting material, and the effect of extending the life of the light emitting device 30 is obtained.

DESCRIPTION OF SYMBOLS 1 Nanohole 2 Alumina layer 5 Anodized alumina film 6 Light emitting layer 7 Luminescent substance 8 Sealing member 10 Light emitting body 21 of anodized alumina film Base 22, 23 Electrode 24 Joining member 25 Light source 27 Frame 28 Air layer 30 Light emitting device a Hole diameter p pitch t thickness

Claims (8)

  A light emitting body using an anodized alumina film, wherein the nanoholes of the anodized alumina film are filled with a light emitting material that emits light by being excited by at least ultraviolet light or blue light, and the light emitting material is filled with the nanohole by a sealing member A light-emitting body of an anodized alumina film characterized by being sealed inside.   2. The phosphor of the anodized alumina film according to claim 1, wherein the anodized alumina film has a thickness of 0.5 to 30 μm, a pore diameter of the nanoholes of 20 to 300 nm, and a pitch of 50 to 500 nm. .   The luminescent material of an anodized alumina film according to claim 1, wherein the luminescent material is made of at least one of a phosphor and a phosphor.   The phosphor according to claim 3, wherein the phosphor is a YAG phosphor.   5. A light emitting device comprising: the light emitting body of the anodized alumina film according to claim 1; and a light source that emits ultraviolet light or blue light.   The light emitting device according to claim 5, wherein a light emitter of the anodized alumina film is disposed on a light emitting side of the light source.   The light emitting device according to claim 5, further comprising an air layer between the light source and the light emitting body of the anodized alumina film. The light-emitting device according to claim 5, wherein the light source is an LED.

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