JPH1041546A - Light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the manufacture of a light-emitting element and to make it possible to emit visible rays of various wavelengths from the light-emitting element without modifying the structure of the semiconductor light-emitting element itself and the composition of a semiconductor by a method in which a fluorescent material, which converts ultraviolet rays emitted from the semiconductor light-emitting element into the visible rays, is provided on the emitting surface of a substrate. SOLUTION: A light-emitting element 1 is formed into a structure, in which a semiconductor light-emitting element 3 for inciding ultraviolet rays A in a substrate 2 is formed on the transparent substrate 2 and a fluorescent material 4 is provided on the emitting surface of the substrate. A current is made to flow through the element 3 to make light emit from the element 3, ultraviolet rays A are emitted through the emitting surface of the substrate 2 to strike the material 4, the wavelength of the rays A is converted into the wavelength of visible rays B and the visible rays B are emitted through the material 4. Moreover, if the element 1 is formed into a constitution, in which a transparent packaging material is provided on the emitting surface of the substrate 2 and the fluorescent material 4 is provided at least to one portion, which is selected from the emitting surface of the substrate, between the emitting surface and the packaging material and the surface of the sheathed material, the material 4 is directly exposed and the material 4 in never separated from the emitting surface of the substrate 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device used as a light source for lighting equipment, display devices, image displays, traffic lights, and the like.

[0002]

2. Description of the Related Art Conventionally, fluorescent lamps and incandescent lamps have been mainly used as light sources for lighting equipment, display devices, traffic lights and the like. As the image display, a cathode ray tube, a liquid crystal display device using a fluorescent lamp as a light source, and the like are used.
Since these conventional light sources have a hollow body structure made of glass, they have disadvantages that they are difficult to miniaturize, are vulnerable to impact, and have a short life. In addition, fluorescent lamps and cathode ray tubes have a problem that the operating voltage is high.

In order to solve the drawbacks of the conventional light source, semiconductor light emitting devices such as an EL device and a light emitting diode (LED) have been developed, and some of them have already been put to practical use. These semiconductor light emitting devices are formed by directly laminating semiconductor layers on a substrate and are integrated with a thin hard substrate, so that they can be miniaturized, resistant to impact, have a long life, and can be driven at a low operating voltage. It has various advantages such as being able to.

In recent years, gallium nitride (GaN) -based high-intensity blue light-emitting diodes have been developed, and full-color display devices using red, green, and blue light-emitting diodes can be manufactured. This gallium nitride-based blue light-emitting diode uses transparent sapphire (Al ₂ O ₃ ) as a substrate, and a GaN (or AlN) buffer layer, an n-type G
An aN layer, an n-type AlGaN layer, a Zn-doped InGaN layer (light-emitting layer), a p-type AlGaN layer, and a p-type GaN layer are sequentially laminated, and electrodes are formed on the n-type GaN layer and the p-type GaN layer, respectively. Have been. When a current is applied between the electrodes, high-luminance blue light is emitted from the substrate side.

In this type of semiconductor light emitting device, the wavelength of the light obtained is determined by the type and composition of the semiconductor in the light emitting layer. Generally, in order to obtain light of a required wavelength, the band gap is set to the emission wavelength. This is achieved by using a suitable semiconductor for the active layer and by doping an element having a transition process corresponding to a wavelength required as an impurity emission center of the semiconductor. In the blue light emitting diode described above, In
Is used Ga nitride _{(In X Ga 1-X N} ) as a light-emitting layer containing, in this case, a method of obtaining light emission of various wavelengths by varying the concentration of indium (In) is taken. For example, to obtain blue light emission, In _x Ga ₁ -xN
Is adjusted to about 0.2, and to obtain green light emission, X is adjusted to about 0.4. In the EL element, Zn
A light emitting layer material obtained by adding various elements to a semiconductor such as S is used, for example, ZnS: Sm for red and Zn for green.
S: Tb and SrS: Ce are used for blue.

[0006]

However, as described above, the conventional light emitting device needs to be manufactured by precisely adjusting the semiconductor composition (doping element concentration) in order to obtain light emission of a desired wavelength (color). In addition, various difficulties are involved in the production, thereby increasing the cost and deteriorating the production yield.

For example, in the above-mentioned blue light emitting diode, although the light emitting layer is made of In _x Ga ₁ -xN, it is generally very difficult to form a semiconductor film containing In. Further, In is hard to be taken into the film, and a very large amount of In is necessary for producing In _x Ga ₁ -xN containing a relatively high concentration of In.
A gas phase source had to be used. That is, this kind of light emitting diode is MOCVD (metal organic chemical vapor deposition)
Each layer is formed by using a method. When an In _x Ga ₁ -xN layer is formed, a large amount of an In gaseous phase source, for example, trimethylindium is required. At the same time, since a high nitrogen partial pressure is required, a large amount of ammonia as a nitrogen raw material is also required. Also, the indium concentration is easily affected by the growth rate,
Substrate, uniformly In _X in particular large-area substrate surface above 8 inches
It is difficult to grow Ga1 _- xN.

Further, in the conventional light emitting element, the red, green, and blue light emitting elements required for performing color display are formed using different semiconductors. Luminance is different, and there is a problem that the balance of each color is deteriorated when displaying them in full color.

The present invention has been made in view of the above circumstances, is easy to manufacture, can emit visible light of various wavelengths without changing the structure of the semiconductor light emitting element itself and the semiconductor composition, and can emit ultraviolet light. An object is to provide a light-emitting element that can emit visible light using a semiconductor light-emitting element that emits light in a wavelength range.

[0010]

According to a first aspect of the present invention, there is provided a semiconductor light emitting device having a transparent substrate and a semiconductor light emitting element for emitting ultraviolet light to the substrate, the semiconductor light emitting element being opposite to the semiconductor light emitting element on the substrate. Is a light-emitting element in which a fluorescent substance that converts ultraviolet light emitted from the semiconductor light-emitting element into visible light is disposed on an emission surface of the semiconductor light-emitting element. The invention according to claim 2 is characterized in that a transparent exterior body is provided on the emission surface of the substrate, and the fluorescent substance is provided on the emission surface of the substrate, between the emission surface and the exterior body, and of the exterior body. 2. The light emitting device according to claim 1, wherein the light emitting device is provided at at least one site selected from a surface and a surface. The invention according to claim 3, wherein the phosphor is provided on at least one site selected from an emission surface of the substrate, a portion between the emission surface and the exterior body, and a surface of the exterior body. The light emitting device according to claim 2, wherein the fine powder is applied. The invention according to claim 4 is characterized in that the fluorescent substance is:
Outgoing surface of the substrate, between the outgoing surface and the exterior body,
3. The light emitting device according to claim 2, wherein the phosphor material layer is printed on at least one site selected from the surface of the exterior body. The invention according to claim 5 is characterized in that the fluorescent substance is provided on at least one site selected from an emission surface of the substrate, a portion between the emission surface and the exterior body, and a surface of the exterior body. 3. The light emitting device according to claim 2, wherein the light emitting device is a phosphor thin film formed by any one of a phase growth method, a sputtering method, and a vacuum deposition method. The invention according to claim 6 is characterized in that a plurality of types of fluorescent substances are arranged on the substrate so that light emitting portions of different colors are generated by ultraviolet light emitted from the semiconductor light emitting element. 6. The light-emitting device according to any one of items 5 to 5. The invention according to claim 7 is that, on the same substrate, a large number of light-emitting units each including the semiconductor light-emitting element and a substrate part that emits any one of red, green, and blue by ultraviolet light emitted from the semiconductor light-emitting element. The light emitting device according to claim 1, wherein the light emitting device is formed. The invention according to claim 8 is characterized in that the semiconductor light-emitting element is one selected from the group consisting of an EL element that emits ultraviolet light, a light-emitting diode, and a semiconductor laser. 2. A light emitting device according to claim 1. Invention, the semiconductor light emitting _{element, ZnS, GaN, Al X Ga} 1 -X N ( provided that, X ≦ according to claim 9
The light-emitting device according to any one of claims 1 to 7, wherein the light-emitting device includes a light-emitting diode including one type selected from the group consisting of diamond and PTFE.

[0011]

FIG. 1 shows a schematic structure of a light emitting device according to the present invention. This light emitting device 1 is a semiconductor light emitting device 3 on a transparent substrate 2 on which ultraviolet light A is incident. Is formed, and an ultraviolet light A emitted from the semiconductor light emitting element 3 is provided on an emission surface of the substrate 2 opposite to the semiconductor light emitting element 3.
Is converted to visible light B.

The material of the substrate 2 is a hard material transparent to ultraviolet light and visible light, for example, single crystal alumina (sapphire),
Magnesia, spinel, stabilized zirconia, yttrium-aluminum-garnet (YAG) and gadolinium
-Garnets such as gallium-garnet, single crystals of fluoride such as topaz, beryl and magnesium fluoride, single crystals of titanate compounds such as barium titanate, transparent ceramics and glasses such as quartz glass and glass, acrylic resins and polycarbonates Of transparent crystal, among which single crystal alumina (sapphire), magnesia, spinel, garnet, beryl, zirconia, and glass, which are excellent in bonding property with the semiconductor light emitting element 3 and excellent in heat resistance, are particularly preferable. Used.

As the semiconductor light emitting element 3, any one of an EL element, a light emitting diode (hereinafter, referred to as an LED), and a semiconductor laser (LD) can be used, and a light emitting element that emits ultraviolet light (wavelength: 275 to 410 nm) is used. used. Examples of such a semiconductor light emitting device that emits ultraviolet light include an EL device using a ZnS semiconductor as a light emitting layer (emission at a wavelength of 326 nm), an LED using GaN as a light emission layer (emission at a wavelength of 365 nm), and Al _X Ga ₁ -XN ( However, X ≦ 0.
4) LED having a light emitting layer (emission of wavelength 275-365 nm), L having a semiconductor characteristic diamond as a light emitting layer
ED (emission of wavelength 410 nm), EL element using polytetrafluoroethylene (PTFE) layer as light-emitting element (wavelength 340)
nm emission).

As the fluorescent substance 4, a fluorescent substance that converts ultraviolet light A emitted from the semiconductor light emitting element 3 into visible light B is used.
A fluorescent substance that emits each color such as red, green, blue, yellow, and light is selected and used. UV light, especially wavelength 200 to 4
Examples of fluorescent substances that emit strong fluorescence (visible light) when excited by long-wavelength ultraviolet light of about 80 nm include Cu-added ZnS (red), Cu and Al-added ZnS (green), and Ag.
Addition (Zn, Cd) S (orange), Cu addition (Zn, Cd)
d) S (yellow), Cu and Mn added ZnS (orange), Mn
ZnS (orange), ZnS with Pb, ZnS with As
(White), Au, Ag, Al-added ZnS (white), Sm and Ce-added SrS (blue), Sm and Ce-added Sr (S, S
e) (green), Eu ²⁺ added (Sr, Ca) ₁₀ (PO ₄ ) ₆
Cl ₂ (blue), Eu ²⁺ added BaMg ₂ Al ₁₆ O ₂₇ (blue), Eu ³⁺ Y ₂ O ₃ (red), Ce ³⁺ Tb ³⁺ added LaP
O ₄ (green), Ce ³⁺ Tb ³⁺ added MgAl ₁₁ O ₁₉ (green), Ce ³⁺ Tb ³⁺ added CdMgB ₅ O ₁₀ (green). These fluorescent materials may be used alone or as a mixture of two or more.

The fluorescent substance 4 may be formed directly on the emission surface of the substrate 2. Further, a transparent exterior body is provided on the emission surface, and the fluorescent substance is at least one selected from an emission surface of the substrate 2, between the emission surface and the exterior body, and a surface of the exterior body. It may be provided at a site. As the exterior body, a transparent hard material having a high transmittance of visible light B, for example, glass, a transparent hard plastic material, or the like is used. The phosphor 4 is a phosphor fine powder applied to at least one site selected from the emission surface of the substrate 2, between the emission surface and the exterior body, and at least one surface of the exterior body, Alternatively, it may be formed as a fluorescent material layer printed on the site, or as a fluorescent material thin film formed on the site by any one of a chemical vapor deposition method, a sputtering method, and a vacuum evaporation method.

In the light emitting device 1, the semiconductor light emitting device 3 is caused to emit a current by causing a current to flow, and the ultraviolet light A is emitted from the emission surface of the substrate 2, impinges on the fluorescent material 4, is wavelength-converted into visible light B, and is converted from the fluorescent material 4. Is emitted. The light-emitting element 1 may be a planar light-emitting element or a lamp shape,
It can be used as a small, long-life light source for display devices, image displays, traffic lights, and the like.

The light-emitting device 1 has a structure in which a semiconductor light-emitting device 3 is formed on a transparent substrate 2 so that ultraviolet light A is incident on the substrate 2, and a fluorescent substance 4 is arranged on an emission surface of the substrate. Since a current is passed through the light emitting element 3 to emit light, the ultraviolet light A is emitted from the emission surface of the substrate 2, impinges on the fluorescent substance 4, is wavelength-converted into visible light B, and is emitted from the fluorescent substance 4. Since it is an integral structure with the device 2, it can be downsized, resistant to impact, has a long life, and can be driven at a low operating voltage. In addition, the semiconductor light emitting element 3 emits ultraviolet light, which was not practically usable in the past, instead of visible light. Thus, it is possible to use a semiconductor light emitting element. By using the semiconductor light-emitting element 3 which is easy to manufacture, the manufacturing cost of the light-emitting element 1 can be reduced and the yield can be improved. In addition, this light emitting element 1
By using the semiconductor light emitting element 3 having the same structure and replacing the fluorescent substance 4 on the substrate 2, the light emitting element 1 that emits visible light B such as red, green, blue, and white can be obtained. ,
Light emitting elements of each color of white can be easily manufactured by the same manufacturing process, and light emission output and luminance of light emitting elements of each color of red, green and blue can be easily adjusted. When performing display, it is possible to obtain a display device capable of displaying a high-quality image with a good balance of each color.

Further, a transparent exterior body is provided on the emission surface of the substrate 2, and at least one selected from an emission surface of the substrate, a portion between the emission surface and the exterior body, and a surface of the exterior body. If the fluorescent material 4 is provided at the site, the fluorescent material 4 is not directly exposed and the fluorescent material 4 does not peel off. The fluorescent substance 4 may be a substance coated with a phosphor fine powder, and can be formed by using an existing apparatus used in the manufacture of a fluorescent lamp. The fluorescent substance 4 may be a fluorescent substance layer formed by printing, for example, a printing paint containing the fluorescent substance 4 in a desired pattern by screen printing, offset printing, or the like. This kind of fluorescent material layer can be mass-produced and a pattern for color display can be easily formed. The fluorescent substance 4 may be a fluorescent substance thin film formed by any one of a chemical vapor deposition method, a sputtering method, and a vacuum deposition method. This fluorescent substance thin film can be formed to be dense and thin with good visible light transmittance. Further, a pattern can be easily formed using a mask, and a pattern with good dimensional accuracy can be formed.

In the light-emitting device 1, a plurality of types of fluorescent substances are arranged on the substrate 2 so that light-emitting portions of different colors are generated by the ultraviolet light A emitted from the semiconductor light-emitting device 3. And thin planar light emitting devices,
For example, a labeling EL element can be manufactured. Furthermore, if a plurality of light emitting units each including the semiconductor light emitting element 3 and a substrate portion that emits any one of red, green and blue by ultraviolet light are formed on the same substrate 2, an integrated and thin color A planar light emitting device for display, for example, a display device for a color display of a television or a personal computer can be manufactured.

In this light-emitting element 1, the semiconductor light-emitting element 3 is selected from the group consisting of an EL element emitting ultraviolet light, a light-emitting diode, and a semiconductor laser. It is possible to commercialize an ultraviolet light emitting element that has not been put into practical use. Further, this semiconductor light emitting device 3 is made of ZnS, GaN, Al _X G
a _1-X N (where X ≦ 0.4), diamond, PT
By using an LED having a light-emitting layer capable of emitting ultraviolet light such as FE, it is necessary to manufacture a light-emitting element by adjusting the amount of doping elements in the light-emitting layer very precisely in order to obtain light of a desired wavelength. This makes it possible to provide a low-cost LED which is easy to manufacture.

Hereinafter, the light emitting device 1 of the present invention will be described more specifically. FIG. 2 shows a first embodiment of a light emitting device according to the present invention.
An element section 12 is provided, and the fluorescent substance layer 1 is provided on the emission surface side of the substrate 11.
8 and an exterior body 19 provided on the outer surface thereof. The EL element section 12 is provided on the substrate 11 with the transparent electrode layer 1.
3, first insulating layer 14, semiconductor layer 15, second insulating layer 1
6 and the metal electrode layer 17 are sequentially laminated.

The exterior body 19 is made of glass or transparent hard plastic. The fluorescent material layer 18 is white, red, blue, and blue by the ultraviolet light A emitted from the EL element unit 12.
A single fluorescent material or a mixture of two or more fluorescent materials that can produce visible light B of each color such as yellow and green is used.
The fluorescent material layer 18 is formed in a state of being thinly and uniformly laminated on the emission surface of the substrate 11 or the surface of the exterior body 19, and its thickness is desirably about 0.1 to 1 μm. Further, as the substrate 11, various transparent hard substrates having high transmittance of ultraviolet light such as quartz glass can be used. The transparent electrode layer 13
It may be formed using a well-known transparent electrode material such as TO (indium-tin oxide). First and second insulating layers 14 and 16
Is made of a transparent material having a high dielectric breakdown strength and a high electric conductivity, for example, Y ₂ O ₃ , Si ₃ N ₄ , Ta ₂ O _5, etc. These may be used alone or in combination of plural kinds. . The material of the metal electrode layer 17 is not particularly limited.
u, Ag, Cu, Al, Ni and the like are used. ZnS may be used as the material of the semiconductor layer 15 that is to be the light emitting layer of the EL element section 12. The semiconductor layer 15 made of a ZnS semiconductor is
It emits ultraviolet light A having a center wavelength of about 335 nm.

The light emitting device 10 includes a transparent electrode layer 13,
Current (AC or DC) between the uppermost metal electrode layer 17
Flowing from the semiconductor layer 15 to a wavelength of 335 nm
A certain amount of ultraviolet light A is emitted, and this ultraviolet light A passes through the substrate 11 and hits the fluorescent material layer 18 to emit visible light B. The visible light B passes through the transparent outer package 19 and exits.

The light emitting device 10 can be used as a small (thin), long-life surface emitting light source device that emits visible light of various colors for illumination and various display devices. Further, by forming a display pattern made of different fluorescent substances on the same substrate 11, it can be used as various kinds of guidance displays and markers. Further, it is possible to form a color display by forming a large number of light-emitting units on the substrate 11 each including the EL element portion 12 and a fluorescent material layer that emits any one of red, green, and blue. is there.

FIG. 3 shows a second embodiment of the light emitting device of the present invention.
It comprises an LED section 22 formed on the substrate 21, a fluorescent substance layer 31 provided on the emission surface side of the substrate 21, and a package 32. The LED section 22 includes, for example, a buffer layer 23 made of GaN or AlN, an n-type GaN layer 24, an n-type AlGaN layer 25, a p-type GaN layer (light-emitting layer) 26, a p-type AlGaN layer 27, -Type GaN layer 28 and p-metal electrode 29 are sequentially laminated, and n-type Ga
It has a so-called double hetero structure in which a part of the N layer 24 is exposed and an n-metal electrode 29 is formed thereon. The structure of the LED unit 22 is not limited to this,
Instead of the p-type GaN layer 24 serving as a light emitting layer, a p-type Al _X G
a _1-X N (where X ≦ 0.4) or low concentration of InG
A double heterostructure using aN or a structure using diamond as a light emitting layer may be used. The LED section 22 having the double hetero structure may be manufactured by using the MOCVD method.

As the substrate 21, a transparent hard substrate, in particular, a single crystal substrate such as a sapphire substrate, a beryl substrate, or a garnet substrate is suitably used. By using this type of substrate 21, an LED (wavelength 365 nm) using GaN as a light emitting layer
(Emission), and the formation of an LED (emission at a wavelength of 275 to 365 nm) using Al _X Ga ₁ -XN (X ≦ 0.4) as a light emitting layer is facilitated. The exterior body 32 is made of glass or transparent hard plastic. The fluorescent material layer 31 is an LED
The white, red, blue,
A single fluorescent material or a mixture of two or more fluorescent materials that can produce visible light B of each color such as yellow and green is used.
The fluorescent material layer 31 is formed in a state of being thinly and uniformly laminated on the emission surface of the substrate 21 or the surface of the package 32, and its thickness is desirably about 0.1 to 1 μm.

This light emitting element 20 has a p metal electrode 29 and an n
Ultraviolet light B is emitted from the LED section 22 by passing a current between the metal electrode 30 and the ultraviolet light B. The ultraviolet light B passes through the substrate 21 and strikes the fluorescent material layer 31 to emit visible light B. The light B passes through the transparent exterior body 32 and is emitted.
The light emitting element 20 is provided on a visible light emitting surface (LED
It is incorporated in a lamp or the like with the side opposite to the part 22 facing upward, and can be used as a light emitting element similar to a conventional LED. Alternatively, a color display may be configured by arranging red, green, and blue in combination. Further, a large number of red, green and blue light emitting portions may be formed on the same substrate to constitute a color display.

[0028]

EXAMPLE An LED having the structure shown in FIG. 3 was prototyped. Example 1: A transparent sapphire substrate having a thickness of 0.33 mm was used as a blue LED substrate, and a buffer layer made of AlN was formed on this substrate.
-Type GaN layer, n-type AlGaN layer _{(Al 0.2 Ga 0 .8 N)} ,
GaN light emitting layer, p-type AlGaN layer (Al _0.2 Ga
_0.8N ), a p-type GaN layer is sequentially formed by MOCVD, and a p-electrode is formed on the p-type GaN layer by n-type GaN.
An n-electrode was formed in a portion where the layer was exposed. An exterior body coated with a separately prepared blue fluorescent substance (Sr and Ce-added SrS) was attached to the emission surface of this substrate, and a blue L
An ED was prepared. This exterior body is provided with a blue fluorescent substance (Sm and Ce-added Sr) on the surface of a glass plate having a thickness of 0.3 mm.
The thin film of S) was produced by a sputtering method. LE made
A DC current of 20 mA was passed between the p and n electrodes of D (drive voltage 20 V). As a result, emission of blue light (center wavelength: 470 nm, emission luminance: 13 cd / m ² ) was recognized from the outer surface of the outer package. When light was emitted without attaching the exterior body to the emission surface of the substrate, ultraviolet light (center wavelength: 365 nm) having no sensitivity to human eyes was emitted.

Example 2 As a green LED fluorescent material, a green fluorescent material (TbOF-added Zn
A green LED having the same configuration as the blue LED was prepared except that S) was used. A direct current was applied to the produced green LED in the same manner as described above. As a result, green light (center wavelength 500 nm, emission luminance 129 cd / m2) was applied from the opposite surface of the substrate.
The emission of ² ) was observed.

Example 3 Red LED having the same structure as the blue LED except that a red fluorescent material (CaS with Eu added) was used as the red fluorescent material.
An ED was prepared. A direct current was applied to the produced red LED in the same manner as described above. As a result, emission of red light (center wavelength: 650 nm, emission luminance: 54 cd / m ² ) was recognized from the opposite surface of the substrate.

Example 4 White LED A white LED having the same structure as the blue LED was prepared except that a white phosphor (Au, Ag, Al-added ZnS) was used as the phosphor. A direct current was applied to the produced white LED in the same manner as described above. As a result, white light was emitted from the opposite surface of the substrate.

Example 5 A transparent sapphire substrate having a thickness of 0.33 mm was used as an LED substrate having a light emitting layer made of AlGaN, and a buffer layer made of AlN, n
-Type GaN layer, n-type AlGaN layer _{(Al X1 Ga 1- X N)} ,
AlGaN light emitting layer (Al _X2 Ga _1-X2 N), p-type AlGa
The N layer (Al _X1 Ga _{1 -X1} N) and the p-type GaN layer are sequentially MOC
A stacked structure was formed by using the VD method, and a p-electrode was formed on the p-type GaN layer, and an n-electrode was formed on a portion where the n-type GaN layer was exposed. However, it is assumed that 0.7 ≧ X1>X2> 0.
When a direct current of 20 mA was applied between the p and n electrodes of the fabricated LED (drive voltage: 20 V), ultraviolet light (center wavelength: 365 nm) insensitive to human eyes was emitted from the substrate emission surface. As a result of examining the light emitting state by alternately attaching the fluorescent substance-containing exterior bodies used in Examples 1 to 4 to the emission surface of the substrate and examining the light emitting state, each color of blue, green, red, and white was obtained as in Examples 1 to 4. Was observed.

Example 6: Having a light emitting layer made of InGaN
0.33mm thick transparent sapphire substrate
And a buffer layer made of AlN, n
-Type GaN layer, n-type AlGaN layer (Al_0.15Ga
_0.85N), InGaN light emitting layer (In)_0.06Ga_0.94N),
p-type AlGaN layer (Al _0.15Ga_0.85N), p-type GaN
Layers are sequentially formed by MOCVD, and p-type G
p electrode on the aN layer, and on the exposed portion of the n-type GaN layer
Each of the n electrodes was formed. P, n current of LED manufactured
DC current of 20 mA was applied between the poles (drive voltage 20 V)
However, purple light (center wavelength 380 n
m) was issued. On the substrate emission surface, in Examples 1-4.
Attach the used phosphor-containing exteriors alternately to emit light
As a result of examining the state, blue, green,
Emission of each color of red and white was observed.

[0034]

As described above, according to the light emitting device of the present invention, a semiconductor light emitting device for making ultraviolet light incident on a transparent substrate is formed on a transparent substrate, and a fluorescent substance is arranged on an emission surface of the substrate. And a current is passed through the semiconductor light emitting element to emit light,
Ultraviolet light is emitted from the emission surface of the substrate, hits the fluorescent substance, is wavelength-converted into visible light and emitted, and emits visible light of each color such as red, green, blue, and white depending on the type of fluorescent substance. It can be integrated with a rigid substrate, is small (thin), resistant to impact, has a long life, and has excellent characteristics such as being driven at a low operating voltage. Lighting equipment, display devices, image displays, It is effective as a new light source such as a traffic light. In addition, a semiconductor light emitting element that emits ultraviolet light, which was not practically usable in the past, instead of visible light, can be used.In order to obtain light of a desired wavelength, the amount of doped elements in the light emitting layer is adjusted very precisely. By using a semiconductor light emitting element that is easy to manufacture, the manufacturing cost of the light emitting element can be reduced and the yield can be improved. In addition, in this light-emitting element, a light-emitting element that emits visible light such as red, green, blue, and white can be obtained by using a semiconductor light-emitting element having the same structure and replacing the fluorescent substance of the substrate with red, green, and blue light. In addition to being able to easily manufacture the light emitting elements of each color of white by the same manufacturing process, it is easy to adjust the light emission output and luminance of the light emitting elements of each color of red, green, and blue. When performing color display, it is possible to obtain a display device capable of displaying a high-quality image with a good balance of each color.

Further, a transparent exterior body is provided on the emission surface of the substrate, and at least one portion selected from the emission surface of the substrate, the space between the emission surface and the exterior body, and the surface of the exterior body. If the fluorescent material is provided, the fluorescent material is not directly exposed and the fluorescent material does not peel off, so that the manufacturing can be facilitated and the yield can be improved, and the fluorescent material can be peeled off during use. And durability can be improved. When the fluorescent substance is formed by applying the phosphor fine powder to the portion, the fluorescent substance can be easily formed by using an existing coating apparatus used in the manufacture of a fluorescent lamp. In the case where a fluorescent material layer containing a fluorescent material is formed at the site by printing, mass production is possible and a pattern for color display can be easily formed. In addition, when a fluorescent substance thin film containing a fluorescent substance is formed at the site by any one of a chemical vapor deposition method, a sputtering method, and a vacuum evaporation method, it can be formed into a dense and thin film having good visible light transmittance. . Further, a pattern can be easily formed using a mask, and a pattern with good dimensional accuracy can be formed.

In the present invention, a plurality of types of fluorescent substances are arranged on the substrate so that light emitting portions of different colors are generated by ultraviolet light emitted from the semiconductor light emitting element. A light emitting element, for example, a labeling EL element can be manufactured. Further, if a plurality of light-emitting units each including a semiconductor light-emitting element and a substrate portion that emits any one of red, green, and blue by ultraviolet light are formed on the same substrate, an integrated and thin color display can be achieved. A planar light emitting element, for example, a display device for a color display of a television or a personal computer can be manufactured.

In the present invention, the semiconductor light emitting device is
By using one type selected from the group consisting of an EL element that emits ultraviolet light, a light-emitting diode, and a semiconductor laser, the practical use of an ultraviolet light-emitting element, which has not been practically used because visible light has not been obtained in the past, has been achieved. It becomes possible. Further, this semiconductor light emitting device is made of ZnS, GaN, Al _x Ga ₁ -xN
(Where X ≦ 0.4), by using an LED having a light emitting layer capable of emitting ultraviolet light such as diamond or PTFE, the amount of the doped element in the light emitting layer can be extremely reduced in order to obtain light of a desired wavelength. Eliminates the need to manufacture light-emitting elements with precise adjustment, making it easier to manufacture and lower cost LEDs
Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a light emitting device of the present invention.

FIG. 2 is a side view showing a first embodiment of the light emitting device of the present invention.

FIG. 3 is a side view showing a second embodiment of the light emitting device of the present invention.

[Explanation of symbols]

 1, 10, 20 ... light emitting element 2, 11, 21 ... substrate 3 ... semiconductor light emitting element 4, 18, 31 ... fluorescent material 12 ... EL element part 19, 32 ... exterior body 22 ... LED part A: Ultraviolet light B: Visible light

Claims (9)

[Claims] 1. A semiconductor light-emitting element for making ultraviolet light incident on a transparent substrate is formed on a transparent substrate, and an ultraviolet light emitted from the semiconductor light-emitting element is formed on an emission surface of the substrate opposite to the semiconductor light-emitting element. A light emitting device comprising a fluorescent substance that converts light into visible light. 2. A transparent exterior body is provided on an emission surface of the substrate, and the fluorescent substance is formed on the emission surface of the substrate, between the emission surface and the exterior body, and from a surface of the exterior body. The light emitting device according to claim 1, wherein the light emitting device is provided at at least one selected site. 3. An emission surface of the substrate, wherein:
3. The light emitting device according to claim 2, wherein a phosphor fine powder is applied to at least one portion selected from between the emission surface and the exterior body and a surface of the exterior body. element. 4. The light-emitting device according to claim 1, wherein the fluorescent substance comprises: an emission surface of the substrate;
3. The light emitting device according to claim 2, wherein the light emitting element is a fluorescent material layer printed on at least one portion selected from between the light emitting surface and the package and a surface of the package. 5. The light-emitting device according to claim 1, wherein the fluorescent material includes: an emission surface of the substrate;
Chemical vapor deposition, at least one portion selected from between the emission surface and the package and the surface of the package;
3. The light emitting device according to claim 2, wherein the light emitting device is a phosphor thin film formed by one of a sputtering method and a vacuum deposition method. 6. The substrate according to claim 1, wherein a plurality of kinds of fluorescent substances are arranged on the substrate so that light emitting portions of different colors are generated by ultraviolet light emitted from the semiconductor light emitting element. The light emitting device according to claim 1. 7. A plurality of light-emitting units each including the semiconductor light-emitting element and a substrate part that emits any one of red, green, and blue by ultraviolet light emitted from the semiconductor light-emitting element are formed on the same substrate. The light emitting device according to claim 1, wherein 8. The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting device is one selected from the group consisting of an EL device that emits ultraviolet light, a light emitting diode, and a semiconductor laser. Light emitting element. 9. The semiconductor light emitting device according to claim 7, wherein the semiconductor light emitting device is ZnS, Ga
_{N, Al X Ga 1-X} N ( provided that, X ≦ 0.4), according to claim 1, characterized in that the light-emitting diode with a diamond, a light emitting layer made of one selected from the group consisting of PTFE 8. The light-emitting device according to any one of items 1 to 7.