JP2006140532A - White luminous device, luminous device and fluorescent material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a luminous device that has proper color-rendering properties and capable of suppressing variation in chromaticity. <P>SOLUTION: The luminous device has proper color-rendering properties and is capable of suppressing variations in chromaticity by a white luminous device having a luminous element, a first fluorescent material having luminous peak wavelength at 575 nm to 630 nm, and a second fluorescent material emitting light from blue system to red system. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light-emitting device using a light-emitting element and a fluorescent material that can be used for a signal lamp, illumination, display, indicator, various light sources, and the like, and more particularly, a fluorescent light that is excited by light emission of a semiconductor light-emitting element and has an emission spectrum in the visible region. The present invention relates to a white light emitting device using a substance.

Today, various semiconductor light emitting devices such as light emitting diodes and laser diodes have been developed. This semiconductor light emitting device can be driven at a low voltage, taking advantage of its small size, light weight, thin shape, long life, high reliability and low power consumption, and as a light source such as a display, backlight, indicator, etc. A part of the tube is being replaced.
In recent years, light-emitting elements that can emit light efficiently from the ultraviolet region to the short wavelength side of visible light have been developed using nitride semiconductors. In this light-emitting element, blue and green LEDs having a quantum well structure having a nitride semiconductor (for example, InGaN mixed crystal) as an active (light-emitting) layer are being developed and commercialized.
Furthermore, a mixed color display including white can be realized by a combination of light from such an LED chip (light emitting element) and a fluorescent material which is excited by the light and emits fluorescence.
Such light emitting diodes are disclosed in, for example, Patent Document 1 (Japanese Patent Laid-Open No. 5-152609), Patent Document 2 (Japanese Patent Laid-Open No. 9-153645), Patent Document 3 (Japanese Patent Laid-Open No. 10-242513), and the like.

Specifically, the light emitting element emits blue light having a relatively short wavelength out of ultraviolet light and visible light, and the light from the light emitting element excites the fluorescent material to emit visible light having a wavelength longer than that of the light emitting element. Is made to emit light. In the configuration using the color mixture of the light emission (visible light) of the light emitting element and the light emission of the fluorescent material, there is an advantage that the structure itself can be simplified and the output can be easily improved, but a color shift tends to occur. On the other hand, when a light emitting element that emits ultraviolet light is used, it is configured to emit white light by combining fluorescent materials capable of emitting RGB (red, green, and blue), and only emits light emitted from the fluorescent material. Since it is used, color adjustment can be performed relatively easily. In particular, when a light-emitting element that emits light in the ultraviolet region is used, the variation in the wavelength of the semiconductor light-emitting element is somewhat absorbed as compared with the case where a semiconductor light-emitting element that emits visible light is used. Since chromaticity can be determined only by color, mass productivity can be improved.
JP 05-152609 A JP 09-153645 A Japanese Patent Laid-Open No. 10-242513

However, in a conventional light emitting device that uses two or more types of fluorescent materials and realizes a predetermined light emission color by mixing light emitted from the fluorescent materials, for example, when the emission wavelength of a light emitting element that is excitation light changes. The emission intensity ratio of the two fluorescent substances changes due to the difference in excitation spectrum between the two fluorescent substances.
Therefore, even in a conventional light emitting device using two or more kinds of fluorescent materials, the variation in the light emission wavelength of the light emitting element affects the chromaticity of the light emitting device, and sufficiently suppresses the chromaticity deviation of the light emitting device. It was difficult.

Further, in order to utilize the advantages of the semiconductor light emitting element and be used as a light source including lighting, conventional light emitting devices are not sufficient, and further improvement in luminance and improvement in mass productivity are required.
In particular, there is no known fluorescent material that can be excited in a long wavelength ultraviolet region or a visible short wavelength region and can emit red light with sufficient luminance.

Therefore, the mixing ratio of the red fluorescent material must be increased, and the relative luminance may be lowered. In addition, when excited on the long wavelength side of the ultraviolet region, the wavelength of the light that excites the fluorescent substance fluctuates due to the wavelength variation of the light emitting element, leading to a decrease in luminance of the red fluorescent substance, resulting in a change in chromaticity of the light emitting device. In some cases.
Therefore, it has been difficult to provide a light emitting device that has a good color rendering property and can suppress a change in chromaticity.

  Furthermore, in order to improve mass productivity, it is desirable that the phosphor can be adjusted to a desired color depending on the composition of the phosphor when the phosphor is excited with light from the ultraviolet region emitted from the light emitting element to the short wavelength side of visible light. It is rare.

The present invention has been made to solve the above-described problems, and a first light-emitting device according to the present invention includes a light-emitting element and a fluorescent material excited by the light-emitting element. Because
The light emitting element has an emission spectrum from the ultraviolet region to the short wavelength region of visible light,
The fluorescent material has an emission spectrum having two or more emission peaks, and at least two of the two or more peaks have a complementary color relationship.
Here, in the present invention, “two peaks are in a complementary color relationship” means that when light of one peak wavelength and light of the other peak are mixed, light in a white region is obtained. For example, blue and yellow, blue green and red, and the like. The white area referred to here includes green white, blue white, purple white, red white and yellow white. Moreover, in this invention, it is preferable that one peak exists in the range of 380 nm-485 nm and the other peak exists in the range of 575 nm-630 nm among two peaks which are complementary color relations.

  In the chromaticity diagram, the colors on the line perpendicular to the locus of black body radiation have the same color temperature even if the colors are different. Therefore, in the direction perpendicular to the locus of black body radiation, a preferred white range cannot be specified due to the difference in color temperature. However, since the light emission is brightest on the locus of black body radiation at the same color temperature, from the viewpoint of light emission efficiency, the mixed color of light of two peak wavelengths having a complementary color relationship is on the locus of black body radiation or It is preferable to set the two peak wavelengths so as to be positioned in the vicinity thereof.

In the present invention, “having an emission spectrum from the ultraviolet region to the short wavelength region of visible light” means that light emission is observed between 340 nm and 440 nm.
With the first light emitting device according to the present invention configured as described above, even when the emission spectrum of the semiconductor light emitting element changes due to manufacturing variations, the emission spectrum of the fluorescent material hardly changes, so the variation in emission color can be reduced. In addition, uneven color tone can be improved.
In the first light emitting device according to the present invention, the main light emitting wavelength of the light emitting element is preferably in the ultraviolet region having a wavelength longer than 360 nm, thereby enabling a relatively simple configuration and a light emitting device with high mass productivity. Can be manufactured.

Furthermore, in the first light emitting device according to the present invention, in two peaks having a complementary color relationship in the emission spectrum of the fluorescent material, the half width of one emission peak on the short wavelength side is larger than the half width of the other emission peak. Narrow is preferred.
In this way, a long wavelength component can be taken out relatively easily and a light emitting device with excellent color rendering can be obtained.

Furthermore, the first light emitting device according to the present invention may have another fluorescent material having a light emission peak between the two light emission peaks in the complementary color relationship.
Thus, a light emitting device that can emit white light and emit light of a desired intermediate color with high luminance can be obtained.

In the first light emitting device according to the present invention, the intensity ratio of the two light emission peaks in the complementary color relationship can be adjusted by the composition of the fluorescent material so as to realize a desired light emission color.
As a result, it is possible to finely adjust the emission color of the white region that can be perceived by humans even with a slight deviation.
A second light emitting device according to the present invention is a light emitting device comprising a light emitting element and a fluorescent material excited by the light emitting element,
The light emitting element has an emission spectrum from the ultraviolet region to the short wavelength region of visible light,
The phosphor is attached with Eu containing one element selected from the group consisting of Mg, Ca, Ba, Sr, and Zn and one element selected from the group consisting of Mn, Fe, Cr, and Sn. It is an activated alkaline earth metal halogen apatite phosphor.
By the second light emitting device according to the present invention, a light emitting device capable of emitting white light with high luminance and having good mass productivity can be realized.

In the first and second light emitting devices according to the present invention, a nitride semiconductor containing at least In and Ga and a nitride semiconductor containing at least Ga and Al can be applied as the light emitting layer of the light emitting element. Thereby, the light emitting element can emit light with high brightness from the ultraviolet region of a long wavelength to the short wavelength of visible light. In addition, since the emission spectrum width of the light emitting element can be narrowed, the fluorescent substance can be excited efficiently and the color tone change of the light emitting device can be suppressed. Needless to say, these include nitride semiconductors containing In, Al, and Ga.
In the first and second light emitting devices according to the present invention, the light emitting element includes an n type nitride semiconductor layer including an n type contact layer, a light emitting layer, and a p type nitride semiconductor including a p type contact layer. Layers are sequentially stacked, and a translucent p-electrode made of a metal including one selected from the group consisting of gold and platinum group elements is provided on almost the entire surface of the p-type contact layer, The film thickness of the translucent p electrode and the n so that the relationship between the sheet resistance Rp (Ω / □) of the conductive p electrode and the sheet resistance Rn (Ω / □) of the n-type contact layer is Rp ≧ Rn It is preferable that the thickness of the mold contact layer is set.

The external quantum efficiency and light emission distribution change depending on the balance between the sheet resistance of the n-type contact layer and the translucent p-electrode, but the external quantum efficiency is compared particularly when the relationship is formed so that Rp ≧ Rn. A suitable light emitting element can be constructed, and a high output light emitting device can be obtained. Moreover, it is preferable that the impurity concentration of each contact layer is 10 < ¹⁷ > -10 < ²⁰ > / cm < ³ >.
In the above-described configuration, the sheet resistance of the translucent p-electrode is preferably 10 (Ω / □) or more, whereby an n-type gallium nitride compound semiconductor having a sheet resistance Rn satisfying Rp ≧ Rn. The layer can be obtained relatively easily.

Moreover, it is preferable that the film thickness of the said translucent p electrode is 50 to 150 inches. As a result, the light transmissivity is sharply improved as compared with the case where the film thickness of the translucent P electrode is thicker than 150 mm, the external quantum efficiency is remarkably improved, and a high-output light emitting device is obtained.
Further, when the translucent p-electrode is formed of a multilayer film or an alloy composed of one kind selected from the group of gold and platinum group elements and at least one other element, the translucent p The sheet resistance of the electrode is preferably adjusted by the content of gold and platinum group elements. Moreover, since gold and platinum group elements have a high short wavelength absorption coefficient, the smaller the content thereof, the better the light transmittance, and it is preferable to contain 20% to 50%.
As described above, the semiconductor light-emitting device used in the present invention has good external quantum efficiency and high output by adjusting the relationship between the translucent p-electrode and the sheet resistance of the n-type contact layer as described above. realizable.

In the first and second light emitting devices according to the present invention, an n electrode formed on the n contact layer in the vicinity of at least one side of the semiconductor light emitting element, and on the translucent p electrode A pedestal electrode formed at a position close to a side opposite to the side where the n electrode is close to, and the pedestal electrode is connected to an extended conductive portion on two lines, and the extended conductive portion is connected to the pedestal. It is preferable that the base electrode extends along the adjacent side on the translucent p-electrode on both sides of the electrode.
At this time, the shape of the pedestal electrode is not particularly limited, and a substantially rectangular shape, a circular shape, or the like can be suitably used. However, when the pedestal electrode becomes small, a phenomenon occurs in which the periphery of the pedestal emits light strongly. Therefore, in the above configuration, a linearly extending conductive portion is provided from the pedestal electrode to increase the strong light emitting region. Moreover, it is preferable that the notch area of the light emission surface performed in order for an n electrode to expose an n-type layer should be made small. Two or more extended conductive portions may be provided.

In the above configuration, the n electrode is provided in the vicinity of at least one side of the light emitting element, and the pedestal electrode is provided in the vicinity of the side opposite to the side where the n electrode is provided. A distribution is obtained.
Furthermore, in the first and second light emitting devices according to the present invention, the n electrode is provided at one corner of the semiconductor light emitting element so as to be close to two sides, and the pedestal electrode is formed at the one corner. It is preferable to be provided at the other corner that forms a diagonal line.

Furthermore, each of the extended conductive portions is preferably formed in an arc shape so as to be equidistant from the n electrode, and a more uniform light emission distribution can be obtained.
In the second light emitting device according to the present invention, the phosphor is preferably an alkaline earth metal halogen apatite phosphor activated with Eu containing at least Mn and / or Cl. This fluorescent material has excellent light resistance and environmental resistance, can efficiently absorb the light emitted from the nitride semiconductor light emitting device, can emit light in the white region, and has an emission spectrum depending on the composition. Can be adjusted. Further, this fluorescent material can absorb yellow and red light with high luminance by absorbing a long wavelength ultraviolet region. Therefore, a light emitting device excellent in color rendering can be configured. Needless to say, alkaline earth metal haloapatite phosphors include alkaline earth metal chloroapatite phosphors.
In the second light emitting device according to the present invention, the fluorescent material may be a fluorescent material represented by (M _1-xy Eu _x M ′ _y ) ₁₀ (PO ₄ ) ₆ Q ₂ (however, M is at least one selected from Mg, Ca, Ba, Sr, and Zn, M ′ is at least one selected from Mn, Fe, Cr, and Sn, and Q is a halogen element such as F, Cl, Br, And at least one selected from I. 0.0001 ≦ x ≦ 0.5, 0.0001 ≦ y ≦ 0.5).
In particular, when Q is Cl, a light emitting device capable of emitting mixed color light with high productivity can be obtained.

In the first and second light emitting devices according to the present invention, in addition to the fluorescent material, BaMg ₂ Al ₁₆ O ₂₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn, (Sr, Ca , Ba) ₅ (PO ₄ ) ₃ Cl: Eu, (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ , SrAl ₂ O ₄ : Eu, Sr ₄ Al ₁₄ O ₂₅ : Eu, ZnS: Cu, Zn ₂ GeO ₄ : Mn, BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn, Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, Gd ₂ O ₂ S: Eu, at least one selected from the group consisting of A seed fluorescent material may be further included.
Accordingly, it is possible to realize a light emitting device capable of finely adjusting the color tone and capable of emitting white light with high color rendering properties with a relatively simple configuration.

The first and second light emitting devices according to the present invention may include a fluorescent material represented by (M _1-x Eu _x ) ₁₀ (PO ₄ ) ₆ Q ₂ in addition to the fluorescent material ( However, M has at least one selected from Mg, Ca, Ba, Sr, and Zn, and Q has at least one selected from halogen elements F, Cl, Br, and I. 0.0001 ≦ x ≦ 0.5, 0.0001 ≦ y ≦ 0.5.)
In this case, in particular, when Q is Cl, a light emitting device capable of emitting white light with higher color rendering properties with a relatively simple configuration can be realized.

A third light emitting device according to the present invention is a light emitting device comprising a light emitting element and a fluorescent material excited by the light emitting element,
The light emitting element has an emission spectrum from the ultraviolet region to the short wavelength region of visible light,
The phosphor is an alkaline earth containing one element selected from the group consisting of Mg, Ca, Ba, Sr and Zn and one element selected from the group consisting of Mn, Fe, Cr and Sn It is a metal halogen apatite phosphor.
This third light emitting device can provide a light emitting device capable of emitting white light with high productivity with high luminance.

  In the third light emitting device, the fluorescent material is preferably an alkaline earth metal halogen apatite phosphor containing at least Mn and / or Cl, whereby the fluorescent material is excellent in light resistance and environmental resistance. It can be. Further, this fluorescent material can efficiently absorb the emission spectrum emitted from the nitride semiconductor.

The 1st-3rd light emitting device comprised as mentioned above utilizes the advantage of a light emitting element, and has the outstanding brightness | luminance and mass-productivity as a light source also including illumination.
In particular, since the fluorescent material has an excitation spectrum in which the number of photons does not change with respect to light having a relatively wide range of wavelengths, unevenness in color caused by variations in the emission spectrum of the semiconductor light emitting element can be improved.
In addition, a light-emitting device can be manufactured with a relatively simple structure and high productivity. In addition, it is possible to obtain a light-emitting device that can extract components having a long wavelength relatively easily and has excellent color rendering properties.
Further, the light emitting device can emit white light, can obtain a desired intermediate color with high luminance, and can adjust a delicate color tone.

Further, a fourth light emitting device according to the present invention is a light emitting device comprising a light emitting element and a fluorescent material excited by the light emitting element,
The light emitting element has an emission spectrum from the ultraviolet region to the short wavelength region of visible light,
The fluorescent material includes a first fluorescent material having an emission spectrum different from that of the light emitting element;
And a second fluorescent material having an emission spectrum different from that of the light emitting element and the first fluorescent material.
Thereby, uneven color tone caused by variation in the emission spectrum of the light emitting element can be improved.
In the fourth light emitting device according to the present invention, the second fluorescent material may be excited by at least one of light emission of the light emitting element and light emission of the first fluorescent material.
In this configuration, a fluorescent material that can be excited by the light emission of the first fluorescent material, even if it is not excited by the semiconductor light emitting device, can be used as the second fluorescent material. Further, in this configuration, the influence due to variation in the emission spectrum of the semiconductor light emitting element can be reduced, chromaticity variation can be suppressed, and uneven color tone can be improved.

In the fourth light-emitting device according to the present invention, the emission spectrum of at least one of the first fluorescent material and the second fluorescent material has two or more peaks, and two of the two or more peaks are It is preferable that they are complementary to each other.
Thereby, it is possible to obtain a light emitting device with little color shift and excellent color rendering.

In the fourth light emitting device according to the present invention, the peak wavelength of the light emitting element and the one peak wavelength in the emission spectrum of at least one of the first and second fluorescent materials are adjusted to be complementary colors. May be.
Further, in the fourth light emitting device according to the present invention, the first fluorescent material is adjusted to have an emission spectrum having a peak wavelength complementary to the peak wavelength in the emission spectrum of the second fluorescent material. May be.
In this way, it is possible to finely adjust the emission color in the light emitting device for light in the white region that is sensitive to humans even with a slight deviation.

In the fourth light emitting device according to the present invention, the main light emission wavelength of the light emitting element is preferably set so as to be located in an ultraviolet region having a wavelength longer than 360 nm.
Thereby, a desired intermediate color can be emitted with high luminance.
In the fourth light-emitting device according to the present invention, a cerium-activated yttrium aluminum oxide-based fluorescent material can also be used as the second fluorescent material.

In the fourth light emitting device according to the present invention, the first fluorescent material is selected from at least one element selected from Mg, Ca, Ba, Sr, and Zn, and at least Mn, Fe, Cr, and Sn. An alkaline earth metal halogen apatite phosphor activated with Eu having one kind of element is preferable.
This fluorescent material is excellent in light resistance and environmental resistance, and can efficiently absorb light emitted from a light emitting device formed using a nitride semiconductor.

  Further, this fluorescent material can emit light in the white region, and the region can be adjusted by the composition. Further, it can absorb yellow and red light with high brightness by absorbing long-wavelength ultraviolet light. Therefore, by using this fluorescent material, a light emitting device having excellent color rendering properties can be obtained. Needless to say, alkaline earth metal chloroapatite phosphors are included as examples of alkaline earth metal halogen apatite phosphors.

In the fourth light emitting device according to the present invention, it is preferable that the first fluorescent material is one fluorescent material selected from the group consisting of the following (1) to (13).
_{(1) (M1 1-a} -b Eu a L1 b) 10 fluorescent substance represented by _{(PO 4)} 6 _{Q 2,}
However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, L1 is at least one selected from Mn, Fe, Cr, Sn, and Q is a halogen element F, Cl, Br. , At least one selected from I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.
(2) a fluorescent substance represented by (M1 _1-a Eu _a ) ₁₀ (PO ₄ ) ₆ Q ₂ ;
However, M1 has at least one selected from Mg, Ca, Ba, Sr, and Zn, and Q has at least one selected from halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5.
(3) a fluorescent substance represented by (M1 _1-ab Eu _a Mn _b ) ₁₀ (PO ₄ ) ₆ Q ₂ ;
However, M1 has at least one selected from Mg, Ca, Ba, Sr, and Zn, and Q has at least one selected from halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.
_{(4) (M2 1-a} -c Eu a Ba c) 10 fluorescent substance represented by _{(PO 4)} 6 _{Q 2,}
However, M2 has at least one selected from Mg, Ca, Sr, and Zn, and Q has at least one selected from halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5 and 0.10 ≦ c ≦ 0.98.
(5) a fluorescent material represented by M1 _1-a Eu _a Al ₂ O ₄ ;
However, M1 has at least 1 sort (s) selected from Mg, Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5.
(6) a fluorescent material represented by M1 _1-ab Eu _a Mn _b Al ₂ O ₄ ,
However, M1 has at least 1 sort (s) selected from Mg, Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.
(7) a fluorescent material represented by M3 _1-ac Eu _a Ca _c Al ₂ O ₄ ;
However, M3 has at least 1 sort (s) selected from Mg, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5 and 0.10 ≦ c ≦ 0.98.
(8) A fluorescent material represented by M4 _1-a Eu _a MgAl ₁₀ O ₁₇ ,
However, M4 has at least 1 sort (s) selected from Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5.
(9) A fluorescent material represented by M4 _1-a Eu _a Mg _1-b Mn _b Al ₁₀ O ₁₇ ,
However, M4 has at least 1 sort (s) selected from Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.
(10) A fluorescent material represented by (M1 _1-a Eu _a ) ₄ Al ₁₄ O ₂₅ ,
However, M1 has at least 1 sort (s) selected from Mg, Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5.
(11) A fluorescent material represented by ZnS: Cu,
(12) A fluorescent material represented by (Zn, Cd) S: Cu, Mn,
(13) A fluorescent material represented by Re ₂ O ₂ S: Eu,
However, Re has at least one selected from Sc, Y, La, Gd, and Lu.

In the fourth light emitting device according to the present invention, the first fluorescent material includes at least a fluorescent material represented by (M1 _1-ab Eu _a L1 _b ) ₁₀ (PO ₄ ) ₆ Q ₂ , One or more fluorescent materials having a composition different from that of the fluorescent material may be included, and the second fluorescent material may be a cerium-activated yttrium aluminum oxide-based fluorescent material. However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, L1 is at least one selected from Mn, Fe, Cr, Sn, and Q is a halogen element F, Cl, Br. , At least one selected from I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.

In the fourth light emitting device according to the present invention, the first fluorescent _material, a fluorescent material represented by _{(M1 1-a-b Eu} a L1 b) 10 (PO 4) 6 Q 2, (M1 1- _a Eu _b ) ₁₀ (PO ₄ ) ₆ Q ₂ , and the second fluorescent material may be a cerium activated yttrium aluminum oxide fluorescent material. However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, L1 is at least one selected from Mn, Fe, Cr, Sn, and Q is a halogen element F, Cl, Br. , At least one selected from I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.

In the fourth light emitting device according to the present invention, the first fluorescent _material, a fluorescent material represented by _{(M1 1-a-b Eu} a L1 b) 10 (PO 4) 6 Q 2, (M1 1- _{a second} fluorescent material containing a fluorescent material represented by _a Eu _a ) ₁₀ (PO ₄ ) ₆ Q ₂ and a fluorescent material represented by (M1 _1-a Eu _a ) ₄ Al ₁₄ O ₂₅ May be a cerium activated yttrium aluminum oxide fluorescent material. However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, L1 is at least one selected from Mn, Fe, Cr, Sn, and Q is a halogen element F, Cl, Br. , At least one selected from I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.

In the fourth light-emitting device according to the present invention, the first fluorescent substance includes at least a fluorescent substance represented by (M1 _1-ab Eu _a L1 _b ) ₁₀ (PO ₄ ) ₆ Q ₂ and (M1 _{1 -A} Eu _a ) ₁₀ (PO ₄ ) ₆ Q ₂ fluorescent material, (M11 _-a Eu _a ) ₄ Al ₁₄ O ₂₅ fluorescent material, and Re ₂ O ₂ S: Eu The second fluorescent material may be a cerium-activated yttrium aluminum oxide-based fluorescent material. However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, L1 is at least one selected from Mn, Fe, Cr, Sn, and Q is a halogen element F, Cl, Br. , I, and Re has at least one selected from Sc, Y, La, Gd, and Lu. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.

  In the fourth light emitting device according to the present invention, the light emitting layer of the light emitting element may be a nitride semiconductor containing at least In and Ga, or may be a nitride semiconductor containing at least Ga and Al. A light-emitting element having these light-emitting layers can emit light with high luminance from a long wavelength ultraviolet region to a short wavelength of visible light. In addition, since this light emitting element can narrow the emission spectrum width, it can efficiently excite the fluorescent material and can emit light having an emission spectrum with a small color change from the light emitting device. Needless to say, these include nitride semiconductors containing In, Al, and Ga.

The fourth light-emitting device according to the present invention can be obtained by mixing fluorescent substances having different emission spectra, thereby obtaining an excitation spectrum in which the number of photons does not change with respect to light having a relatively wide range of wavelengths. Color unevenness caused by variations in emission spectra can be improved.
In particular, the second fluorescent material can be excited even by light from the first fluorescent material excited by the semiconductor light emitting element, so that a light emitting device with better color rendering can be obtained. . In addition, a light-emitting device with high productivity can be provided with a relatively simple configuration. The fourth light-emitting device according to the present invention can extract a long wavelength component relatively easily and can be a light-emitting device with excellent color rendering. In addition, a light-emitting device that can emit white light, emit a desired intermediate color with high luminance, and can finely adjust the color tone can be obtained.

According to the present invention, it is possible to provide a light emitting device that has good color rendering properties and can suppress a change in chromaticity.
Moreover, according to this invention, the light-emitting device which can be adjusted to a desired color with the composition of a fluorescent substance can be provided.

Embodiments according to the present invention will be described below.
Embodiment 1 FIG.
The light-emitting device of Embodiment 1 according to the present invention is
(1) a semiconductor light emitting device that emits light of a wavelength in the ultraviolet region;
(2) a fluorescent material that includes at least one fluorescent material (first fluorescent material) that is excited by ultraviolet light from the light emitting element and has an emission spectrum having two peaks in complementary colors;
Are combined to emit light emitted from the fluorescent material.
As described later, the light emitting device of the first embodiment configured as described above is almost unaffected by variations in the light emission wavelength of the light emitting element, so that the light emission color is determined only by the light emission spectrum of the fluorescent material. As a result, it is possible to reduce variations in chromaticity and to provide extremely advantageous effects as compared with the conventional example, which is excellent in mass productivity and reliability.

That is, in the light emitting device of the first embodiment, as schematically shown in FIG. 8, even if the emission wavelength of the light emitting element in which the first fluorescent material is excitation light changes by Δλ, the intensity of the emission spectrum However, since the intensity ratio between the two peaks hardly changes, the color tone rarely changes.
Therefore, in the light-emitting device of Embodiment 1, even if the light emission wavelength of the light-emitting element varies, the light-emitting device rarely appears as a chromaticity shift of the light-emitting device.
In contrast, in a conventional light emitting device that realizes a predetermined light emission color by mixing light emitted from a light emitting element and light emitted from a fluorescent material, variation in the light emission wavelength of the light emitting element directly affects the chromaticity of the light emitting device. Therefore, it will appear as a chromaticity shift of the light emitting device.
In particular, since the semiconductor light emitting device is formed by using the MOCVD method or the like, the variation occurs even within the same wafer, and the variation is extremely large compared to the fluctuation (variation) of the emission spectrum of the fluorescent material. Therefore, a light-emitting device that uses light from a semiconductor light-emitting element as it is may be a light-emitting device with extremely large variations.

Further, as in the first embodiment, when the emission spectrum emitted from the light emitting element is in the ultraviolet region or in the visible region where the visibility is very low (for example, 420 nm or less), the light emitted from the light emitting element is directly output Even if done, it has little effect on the chromaticity of the light emitting device.
As described above, the light-emitting device according to Embodiment 1 of the present invention is configured using the first fluorescent material that is excited by ultraviolet light and has an emission spectrum having two peaks that are complementary to each other. Therefore, the chromaticity variation can be extremely reduced.

In addition, since the light-emitting device of Embodiment 1 can absorb variations in the light-emitting elements and reduce chromaticity variation, the manufacturing yield can be increased (excellent mass productivity).
Furthermore, the light-emitting device of Embodiment 1 is excellent in reliability because the light-emitting wavelength of the light-emitting device does not change even if the light-emitting wavelength of the light-emitting element changes over time.
Furthermore, in the light emitting device of the first embodiment, as will be clarified by the examples described later, the composition of the fluorescent material can be adjusted according to the target chromaticity, and the color tone of the light emitting device can be adjusted. Simple.
Further, as will be described later, for example, by using another fluorescent material having a peak between two peaks, an emission color closer to a desired color tone can be realized.

  Hereinafter, a specific configuration of the light emitting device of the first embodiment will be described in more detail with reference to FIG. The light-emitting device of the first embodiment is a surface-mounted light-emitting device as shown in FIG. In the light emitting device of the first embodiment, as the light emitting element 1, as shown in FIG. 7, a nitride semiconductor light emitting element (LED chip) having an InGaN light emitting layer whose composition is set so that the emission peak wavelength is about 370 nm. Is used. This LED chip has an n-type GaN layer that is an undoped nitride semiconductor, an Si-doped GaN layer that is an n-type contact layer for forming an n-type electrode, and an n-type nitride semiconductor that is an undoped nitride semiconductor on a sapphire substrate. Type GaN layer, nitride semiconductor n-type AlGaN layer, light emitting layer InGaN layer with single quantum well structure, Mg-doped p-type cladding layer AlGaN layer, Mg-doped p-type contact layer It has an element structure in which GaN layers are sequentially stacked. In the first embodiment, a buffer layer composed of a GaN layer grown at a low temperature in advance is formed on a sapphire substrate, and the p-type semiconductor is annealed at 400 ° C. or higher after film formation. To do. Further, in this LED chip, a part of the surface of the n-type contact layer is exposed on the same side as the p-type contact layer by etching, and an n-electrode is formed in a strip shape on the exposed n-type contact layer. A translucent p-electrode made of a metal thin film is formed on almost the entire surface of the mold contact layer. Further, a pedestal electrode is formed on the translucent p-electrode in parallel with the n-electrode using a sputtering method.

  In the light emitting device according to the first embodiment, the package 5 is inserted into a Kovar base having a concave portion in which the LED chip 1 provided in the central portion is disposed, and through holes 3 formed on both sides of the concave portion of the base. The lead electrode 2 made of Kovar. Here, the lead electrode 2 is provided through an insulating sealing material so that the lead electrode 2 is insulated from the Kovar base in the through hole 3 of the base and is kept airtight. A Ni / Ag layer is formed on the surfaces of the package 5 and the lead electrode 2. The LED chip 1 is die-bonded with an Ag—Sn alloy in the concave portion of the package 5 configured as described above. By constituting in this way, all the constituent members of the light emitting device can be made of an inorganic substance, and the light emitted from the LED chip 1 is remarkably reliable even if the light emitted from the LED chip 1 is in the ultraviolet region or the short wavelength region of visible light. Can be a high light emitting device.

Each electrode of the die-bonded LED chip 1 is electrically connected to each lead electrode 2 exposed on the bottom surface of the package base by an Ag wire 4. And the light emitting device of Embodiment 1 is sealed with the Kovar lid 6 which has the glass window part 7 in the center part. The Kovar lid 6 and the package base are hermetically sealed by seam welding after sufficiently removing moisture in the recesses of the package 5. The inside of the glass window 7 of the Kovar lid 6 is coated with a slurry made of 90 wt% nitrocellulose and 10 wt% γ-alumina containing a fluorescent substance 8 and then heated and cured at 220 ° C. for 30 minutes. A color conversion member 80 is formed in advance.
In the first embodiment, various fluorescent materials described later can be used.

The light-emitting device (light-emitting diode) according to Embodiment 1 configured as described above can emit white light with high luminance.
For example, in the first embodiment, the fluorescent material 8 is an alkaline earth metal chlorapatite phosphor (first fluorescent material) activated with Eu containing at least Mn (Sr _0.96 , Eu _{0. When 01} , Mn _0.03 ) ₁₀ (PO ₄ ) ₆ Cl ₂ and a SrAl ₂ O ₄ : Eu fluorescent material are used, the emission characteristics shown in FIG. 1 can be obtained.
In FIG. 1, the peak around 460 nm and the peak around 580 nm are peaks due to (Sr _0.96 , Eu _0.01 , Mn _0.03 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor, The peaks are complementary to each other. In addition, light emission in the vicinity of about 520 nm shows the light emission spectrum of the SrAl ₂ O ₄ : Eu phosphor. In this example, the (Sr _0.96 , Eu _0.01 , Mn _0.03 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor having two peaks has almost desired chromaticity, and more desired chromaticity. In order to make it closer, chromaticity is adjusted by supplementing the green shortage with a SrAl ₂ O ₄ : Eu phosphor, which is a green phosphor.

  As described above, the light emitting device of this example can reduce chromaticity variation by using the first fluorescent material having two peaks, and can further easily adjust the chromaticity by using the second fluorescent material. Excellent in mass productivity and reliability.

Hereafter, each structure of the light-emitting device of this Embodiment 1 is explained in full detail.
(Semiconductor light emitting device)
In the present invention, as the semiconductor light emitting device, a semiconductor light emitting device having a light emitting layer capable of emitting light having an emission wavelength capable of efficiently exciting a fluorescent material is used.
Examples of the material of such a semiconductor light emitting device include various semiconductors such as BN, SiC, ZnSe, GaN, InGaN, InAlGaN, AlGaN, BAlGaN, and BInAlGaN. Alternatively, an element having Si or Zn as an impurity element and having an emission center as an impurity element can be used. Nitride semiconductors (for example, nitride semiconductors containing Al and Ga, nitride semiconductors containing In and Ga) as light emitting layer materials capable of efficiently emitting short wavelengths of visible light from the ultraviolet region where phosphors can be excited efficiently As In _X AlYGa _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is particularly suitable.

  In addition, examples of the structure of the semiconductor light emitting device include a homo structure having a MIS junction, a PIN junction, a pn junction, and the like, a hetero structure, and a double hetero structure. By adjusting the mixed crystal ratio of the semiconductor material, the emission wavelength can be set corresponding to the excitation wavelength of the fluorescent substance. Further, the output can be further improved by making the active layer a single quantum well structure or a multiple quantum well structure.

  When a light-emitting element is configured using a nitride semiconductor, a substrate made of a material such as sapphire, spinel, SiC, Si, ZnO, GaAs, or GaN can be used. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by HVPE method, MOCVD method or the like. More preferably, a buffer layer made of GaN, AlN, GaAIN or the like is grown on the sapphire substrate at a low temperature to form a non-single crystal, and a nitride semiconductor having a pn junction is formed thereon.

An example of a light-emitting element that uses a nitride semiconductor and can efficiently emit light in the ultraviolet region is a light-emitting element having a double hetero structure manufactured by the following procedure.
First, a buffer layer is formed on a sapphire substrate, and SiO ₂ is formed on the buffer layer in a stripe shape substantially perpendicular to the orientation flat surface of the sapphire substrate.

Next, GaN is grown on the stripe by HVPE method using ELOG (Epitaxial Lateral Over Growth GaN).
Subsequently, the first contact layer made of n-type gallium nitride, the first cladding layer made of n-type aluminum nitride / gallium, the well layer made of indium nitride / aluminum / gallium, and made of aluminum nitride / gallium by MOCVD. An active layer having a multiple quantum well structure in which a plurality of barrier layers are stacked, a second cladding layer made of p-type aluminum nitride / gallium, and a second contact layer made of p-type gallium nitride are sequentially stacked.
Then, etching is performed from the p-type layer side to expose a part of the surface of the n-type contact layer, and electrodes are formed on the p-type and n-type contact layers, respectively, and then divided into individual chips. Thereby, an LED chip can be produced.

In this configuration, the active layer can be formed into a ridge stripe shape and sandwiched between guide layers, and a resonator end face can be provided to provide a semiconductor laser device that can be used in the present invention.
The nitride semiconductor exhibits n-type conductivity without being doped with impurities. However, since it is necessary to set a desired carrier concentration or the like to a predetermined value, in that case, Si, Ge, Se, Te, C, etc. are used as n-type dopants in order to form an n-type nitride semiconductor. Is preferably introduced as appropriate. On the other hand, when forming a p-type nitride semiconductor, the p-type dopants such as Zn, Mg, Be, Ca, Sr, and Ba are doped. At this time, since it is difficult for the nitride semiconductor to become p-type simply by doping with a p-type dopant, it is preferable to lower the resistance by heating in a furnace or plasma irradiation after introducing the p-type dopant.

Further, in the semiconductor light emitting device used in the present invention, the sheet resistance of the n-type contact layer formed at an impurity concentration of 10 ¹⁷ to 10 ²⁰ / cm ³ and the sheet resistance of the translucent p electrode satisfy Rp ≧ Rn. It is preferable to adjust so that it may become a relationship. The n-type contact layer is preferably formed to a film thickness of, for example, 3 to 10 μm, more preferably 4 to 6 μm, and the sheet resistance is estimated to be 10 to 15Ω / □, so that Rp at this time is the sheet resistance value. It is good to form in a thin film so that it may have the above sheet resistance values. The translucent p-electrode may be formed of a thin film having a thickness of 150 mm or less.

  Further, when the translucent p-electrode is formed of a multilayer film or alloy composed of one kind selected from the group consisting of gold and platinum group elements and at least one other element, it is contained. Stability and reproducibility are improved by adjusting the sheet resistance of the translucent p-electrode according to the content of the gold or platinum group element. Since gold or a metal element has a high absorption coefficient in the wavelength region of the semiconductor light emitting device used in the present invention, the smaller the amount of gold or platinum group element contained in the translucent p-electrode, the better the transparency. In the conventional semiconductor light emitting device, the relationship of sheet resistance is Rp ≦ Rn. In the present invention, Rp ≧ Rn, and therefore the translucent p-electrode is formed thinner than the conventional one. At this time, thinning can be easily performed by reducing the content of gold or platinum group elements.

As described above, in the semiconductor light emitting device used in the present invention, the sheet resistance RnΩ / □ of the n-type contact layer and the sheet resistance RpΩ / □ of the translucent p electrode satisfy the relationship of Rp ≧ Rn. It is preferable. It is difficult to measure Rn after fabricating a semiconductor light emitting device, and it is practically impossible to know the relationship between Rp and Rn. However, from the state of the light intensity distribution during light emission, what Rp and Rn You can know if they are in a relationship.
In addition, a p-side pedestal electrode is formed on a part of the translucent p-electrode formed on almost the entire surface of the p-type contact layer.

Hereinafter, a preferred arrangement of the electrodes in the present invention will be described with reference to FIGS.
In the light emitting device of the present invention, as shown in FIGS. 13 and 14, the n-electrode 53 is formed so as to be close to at least one side of the semiconductor light emitting device. In the example shown in FIG. 13 and FIG. 14, a cutout portion 51 a in which the n-type contact layer 51 is exposed by removing a part of the p-type layer and the active layer by etching is provided at the center of one side thereof. An n-electrode 53 is formed in the notch 51a.

  The p-side pedestal electrode 55 is formed on the translucent p-electrode 54 at a position adjacent to the side facing the side where the n-electrode is close. The p-side pedestal electrode 55 is connected to an extended conductive portion 56 on two lines, and the extended conductive portion 56 extends along sides adjacent to the pedestal electrodes 55 on both sides of the pedestal electrode 55. In the present invention, by forming the p-side pedestal electrode 55 and the n-electrode 53 in such a positional relationship, the active layer located between the p-side pedestal electrode 55 and the n-electrode 53 can efficiently emit light, Furthermore, by forming the extended conductive portion 56 connected to the p-side pedestal electrode 55 so as to be electrically conductive on the translucent p-electrode 54, current can be effectively diffused throughout the p-layer, The entire light emitting layer can be made to emit light efficiently.

Further, according to the study by the present inventors, it has been confirmed that light emission with high luminance can be obtained in the peripheral portions of the p-side pedestal electrode 55 and the extended conductive portion 56.
Therefore, in the present invention, it is more preferable to effectively use light emission with high luminance in the peripheral portion of the extended conductive portion 56.

  More specifically, the extended conductive portion 56 and the peripheral portion where the above-described high-luminance light emission is obtained are secured between the extended conductive portion 56 and the edge of the light emitting layer and the p layer formed along the extended conductive portion 56. As described above, it is preferable to leave a space between the edge and the extended conductive portion 56. When the sheet resistance RnΩ / □ of the n-type contact layer 51 and the sheet resistance RpΩ / □ of the translucent p-electrode 54 satisfy the relationship of Rp ≧ Rn, the edge of the extended conductive portion 56 and the light emitting layer Is preferably 20 μm or more and 50 μm or less. This is because if the interval is smaller than 20 μm, a sufficient peripheral region where light emission with high luminance can be obtained cannot be secured (the region where light emission with high luminance should be obtained protrudes outside). This is because a portion having a low emission luminance is formed along the line, resulting in a decrease in luminance as a whole.

Further, as shown in FIG. 13, each of the extended conductive portions 56 is preferably formed in an arc shape so as to be equidistant from the n-electrode 53, thereby providing a linear shape as shown in FIG. Compared to the case, a more uniform emission distribution can be obtained.
Furthermore, in the present invention, as shown in FIGS. 15 and 16, an n-electrode 63 is provided at one corner of the semiconductor light emitting device so as to be close to two sides, and the pedestal electrode is close to the n-electrode 63. More preferably, it is provided at the other corner that is diagonal to the corner.

Even when the n-electrode 63 and the p-side pedestal electrode 65 are arranged diagonally, as shown in FIGS. 15 and 16, the extended conductive portions 66 are circular so as to be equidistant from the n-electrode 63. It is preferably formed in an arc shape, and thereby, higher luminance and more uniform light emission can be obtained.
Furthermore, it is preferable that the distance between the extended conductive portion 66 and the edge of the light emitting layer is 20 μm or more and 50 μm or less in order to sufficiently secure a region where light emission with high luminance can be obtained.

  In the light emitting device of the present invention, it is preferable to use a resin in order to form it with high productivity. In this case, considering the emission wavelength from the fluorescent material and the deterioration of the light transmitting resin, the light emitting element is It has an emission spectrum in the ultraviolet region, and its main emission wavelength is preferably from 360 nm to 420 nm, more preferably from 370 nm to 410 nm. In order to further improve the excitation and emission efficiency of the light emitting element and the fluorescent material, 380 nm to 400 nm is more preferable.

(Fluorescent substance 8)
In the light-emitting device of the first embodiment, a fluorescent material that is excited by light emission of the semiconductor light-emitting element and can efficiently emit light having a wavelength different from the excitation light is used. It is preferable that the substance includes at least an ultraviolet region in an excitation region. In Embodiment 1, the fluorescent material absorbs at least part of light from the semiconductor light emitting element in the ultraviolet region having a wavelength longer than 360 nm, and emits light having an emission spectrum having two or more emission peaks. A first fluorescent material that emits light. It is preferable that at least two of the two or more peaks of the first fluorescent material have a complementary color relationship. Furthermore, in the emission spectrum of the first fluorescent substance, it is preferable that one of the two emission peaks having a complementary color relationship is the maximum emission peak in the emission spectrum and the other is 50% or more of the maximum emission peak. Furthermore, it is preferable that any one of the two emission spectra in the complementary color relationship includes a red component. As a specific fluorescent material satisfying such conditions, for example, an alkaline earth metal halogen apatite phosphor activated with Eu containing at least Mn and / or Cl can be cited.

This fluorescent material can be produced by the following method. First, a predetermined amount of a phosphate oxide or a compound that can be converted into an oxide by thermal decomposition, which is a constituent element of the fluorescent material, and ammonium chloride are weighed and mixed by a ball mill or the like. Next, the mixed raw material is put in a crucible and fired at a temperature of 800 ° C. to 1200 ° C. for 3 to 7 hours in a reducing atmosphere of N ₂ and H ₂ . The obtained fired product can be pulverized wet, sieved, dehydrated and dried to obtain an alkaline earth metal halogen apatite phosphor.

Further, in the present invention, the general formula (M _1-xy Eu _x M ′ _y ) ₁₀ (PO ₄ ) ₆ Q ₂ (where M is at least one selected from Mg, Ca, Ba, Sr, Zn) Species, M ′ is at least one selected from Mn, Fe, Cr, Sn, and Q is at least one selected from halogen elements F, Cl, Br, I.) A metal halogen apatite phosphor can be used. In this case, in the above general formula, the composition ratio x of the first activator Eu element is preferably set in the range of 0.0001 ≦ x ≦ 0.5. The reason is that when x is less than 0.0001, the light emission luminance decreases, and even when x exceeds 0.5, the light emission luminance tends to decrease due to concentration quenching. In this case, more preferably, 0.005 ≦ x ≦ 0.4, and still more preferably 0.01 ≦ x ≦ 0.2.

In the above general formula, y represents the composition ratio of at least one element of Mn, Fe, Cr, and Sn, preferably 0.0001 ≦ y ≦ 0.5, more preferably 0.005. ≦ y ≦ 0.4, and more preferably 0.01 ≦ y ≦ 0.3. If y exceeds 0.5, the emission luminance tends to decrease due to concentration quenching.
This fluorescent substance is excited by ultraviolet light from a relatively short wavelength of visible light (for example, the main wavelength is 440 nm or less), so that the visible light is converted from blue to white (for example, white in the conventional color of JIS Z8110, Or, the light emission color from red to white is the basic color of the system color name diagram.

In particular, the above-mentioned alkaline earth metal halogen apatite phosphor can be excited efficiently even by ultraviolet rays having a relatively long wavelength of about 365 nm, can emit light with high brightness, and contains a red component sufficiently. It is also possible to obtain good color rendering properties with a color rendering index Ra of 80 or more.
The CIE chromaticity diagram of FIG. 3 shows the emission colors when the fluorescent materials used in Examples 1, 9, and 17 described later are excited by light of 365.5.0 nm. It can be seen from FIG. 3 that the fluorescent substance used in the present invention can be changed in various colors from blue to white to red to adjust the color tone by changing the composition ratio.
That is, when M is Sr, the emission color is blue due to the emission of Eu ²⁺ having a peak in the vicinity of 450 nm, but when the value of y is increased with Mn of M ′, the emission of the fluorescent material by the emission of Mn. The color comes to show blue to white to red emission colors. When M is Ca, similar changes are shown corresponding to the amounts of Eu and Mn, but when M is Ba, the emission color changes little.

The broken line in FIG. 4 shows the emission spectrum of the fluorescent material used in Example 1 by excitation at 365 nm, the broken line in FIG. 5 shows the excitation spectrum of the fluorescent material used in Example 1 with respect to 450 nm emission, and the broken line in FIG. The excitation spectrum with respect to 590 nm emission of the fluorescent material used in Example 1 is shown. From this FIG. 6, this fluorescent substance used in the present invention is efficiently excited by long-wavelength ultraviolet light to relatively short-wavelength visible light (for example, 230 to 300 nm to 400 nm to 425 nm), and the emission color is as described in JIS, Z8110. It can be seen that the basic color name is included in the white area. In addition, since this fluorescent substance is efficiently excited in the whole ultraviolet region, it can be expected that it can be effectively used for short wavelength ultraviolet rays.
The solid line in FIG. 4 shows the emission spectrum of the fluorescent material used in Example 9 described later by excitation at 365 nm. It can be seen that the fluorescent material used in Example 9 has a relatively broad emission spectrum having peaks at both about 460 nm and about 600 nm.

The solid line in FIG. 5 shows the excitation spectrum for the 460 nm emission of the fluorescent material used in Example 9, and the solid line in FIG. 6 shows the excitation spectrum for the 600 nm emission of the fluorescent material used in Example 9.
A light emitting device using these fluorescent materials can be excited by an ultraviolet LED or an ultraviolet LD to emit light having an emission spectrum having two peaks of about 460 nm and about 580 nm. In this emission spectrum, the spectral component near 460 nm and the spectral component near 580 nm are complementary to each other. In the present invention, when higher color rendering is desired, the alkaline earth metal halogen apatite phosphor activated with Eu containing at least Mn and / or Cl is used as a fluorescent material that emits green light: SrAl ₂ O ₄ : By adding Eu, the color rendering can be further improved.

Furthermore, the above-mentioned fluorescent substance can contain one type selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti in addition to Eu as desired.
Moreover, it is preferable to adjust the particle size of a fluorescent substance to the range of 1 micrometer-100 micrometers, More preferably, it adjusts to the range of 5 micrometers-50 micrometers. A more preferable range is 10 μm to 30 μm. A fluorescent material having a particle size smaller than 10 μm tends to form an aggregate relatively easily. In addition, by setting the particle size within the above range, the light absorption rate and the conversion efficiency of the fluorescent material can be increased, and the width of the excitation wavelength can be increased. Thus, by including a large particle size fluorescent material having optically excellent characteristics, light having a wavelength around the main wavelength of the light emitting element can be converted and emitted well, and aggregation can be prevented. Therefore, the mass productivity of the light emitting device can be improved.

  Here, the particle size is indicated by a value obtained from a volume-based particle size distribution curve. The volume-based particle size distribution curve is obtained by measuring the particle size distribution by a laser diffraction / scattering method, and specifically, hexametaphosphoric acid having a concentration of 0.05% in an environment of an air temperature of 25 ° C. and a humidity of 70%. Each substance can be dispersed in a sodium aqueous solution and measured with a laser diffraction particle size distribution analyzer (SALD-2000A) in a particle size range of 0.03 μm to 700 μm. The central particle size is a particle size value when the integrated value is 50% in this volume-based particle size distribution curve, and the central particle size of the fluorescent material used in the present invention is in the range of 15 μm to 50 μm. Brightness can be further increased. Moreover, in this invention, it is preferable that the fluorescent material which has this center particle size value is contained frequently, and, specifically, a frequency value is 20 to 50%. By using a fluorescent material with small variation in particle size in this way, color unevenness can be further suppressed and a light emitting device having a good color tone can be obtained.

Embodiment 2. FIG.
Hereinafter, the light emitting device according to the second embodiment of the present invention will be described.
The light emitting device of the second embodiment is configured in the same manner as in the first embodiment except that the fluorescent material is different from that in the first embodiment.
The light emitting device of the second embodiment utilizes the fact that the variation variation width of the light emitted from the fluorescent material that is excited and emitted by the light emitting element is smaller than the variation variation width of the light emitted by the light emitting element. Thus, a light emitting device with small color shift is realized.

  That is, the semiconductor light emitting element is formed using the MOCVD method or the like, but the emission wavelength varies even within the same wafer. Therefore, a light emitting device that uses light from a semiconductor light emitting element as it is may be a light emitting device with extremely large variation. On the other hand, in the light emitting device of the second embodiment, when a light emitting element having an emission spectrum in the ultraviolet region or visible light with extremely low visibility (for example, 420 nm or less) is used, light emitted from the light emitting element It was completed by finding that the variation in the spectrum can be absorbed by the fluorescent material described later.

  Specifically, the light-emitting device of Embodiment 2 includes a first fluorescent material excited by a semiconductor light-emitting element, and a second light emission spectrum different from both the first fluorescent material and the semiconductor light-emitting element. And a fluorescent material. Thereby, the light emission excellent in color rendering can be obtained by suppressing the variation in the emission wavelength. That is, in the light emitting device of the second embodiment, as shown in FIG. 9, the emission spectra of the two fluorescent materials have two or more peaks, and the color shift of the fluorescent material itself can be reduced, and the color shift of the light emitting device is reduced. Can be suppressed. Further, in the light emitting device of Embodiment 2, it is preferable that at least two of the two or more peaks of the fluorescent material are in a complementary color relationship with each other, whereby the color tone shift of the fluorescent material itself can be extremely reduced, Color tone shift of the light emitting device can be suppressed. Further, when the second fluorescent material is excited by the light emission of the first fluorescent material, the color deviation is less and stable light emission can be obtained. This is excited by the semiconductor light emitting element, and the second fluorescent material is further excited by the light from the first fluorescent material whose variation is smaller than that of the excitation light, so that a stable light emitting device with less color shift is obtained. It is thought that it is possible.

  Further, by using two or more kinds of fluorescent materials as in the second embodiment, the color tone of the light emitting device can be easily adjusted. For example, another fluorescence having another peak between two peaks in a complementary color relationship. Color shift can be suppressed by using a substance.

Hereinafter, the fluorescent material used in the light emitting device of the second embodiment will be described in detail.
(Fluorescent substance)
The fluorescent material used in the light emitting device of the second embodiment includes a first fluorescent material that can emit light efficiently by an emission spectrum from the semiconductor light emitting element, and an emission spectrum different from that of the first fluorescent material and the semiconductor light emitting element. And a second fluorescent material. The second fluorescent material may be a fluorescent material that can emit light when excited by an emission spectrum from the first fluorescent material. The first fluorescent material and the second fluorescent material can be sufficiently used alone, but in the second embodiment, by using both the first fluorescent material and the second fluorescent material, more color can be obtained. A light-emitting device with less deviation and excellent color rendering properties is formed. Accordingly, the fluorescent materials described below include fluorescent materials that can be used alone. In the light emitting device according to the second embodiment, the first and second fluorescent materials can efficiently use light of wavelengths serving as the respective excitation sources, and also use the mixed color light emitted from the two fluorescent materials. Therefore, a light emitting device with excellent color rendering can be realized.

  Each of the first and second fluorescent materials may be one kind, or each may be composed of two or more kinds. Thereby, a combination of emission spectra is greatly expanded, and a light emitting device having excellent characteristics such as color rendering properties and light emission luminance can be realized by selecting an appropriate combination. Moreover, when they are complementary colors, it is possible to emit white light efficiently. In addition, when the second fluorescent material is excited by the first fluorescent material and two or more types of the first fluorescent material are used, all of the first fluorescent materials are the second fluorescent material. It does not have to be an excitation source of the fluorescent material, and any one of the first fluorescent materials only needs to excite the second fluorescent material. The second fluorescent material may be excited by both the first fluorescent material and the semiconductor light emitting element.

  Even if the first and second fluorescent materials are one kind or two kinds or more, it is possible to make the first fluorescent material and the second fluorescent material complementary colors. is there. Thereby, it can be set as the light-emitting device excellent in color rendering property. In addition, color unevenness can be suppressed as compared to the case where two or more of the first and second fluorescent materials are used and complementary colors are obtained. For example, when two types of first fluorescent materials are used and they are complementary colors, if one of the fluorescent materials deteriorates due to heat or the like, the color tone balance is lost and the color tone changes over time. The same applies to the case where two or more types of second fluorescent materials are used and they are complementary to each other. However, when the first fluorescent material and the second fluorescent material are complementary to each other and the second fluorescent material is excited by the first fluorescent material, the first fluorescent material Since the second fluorescent material is difficult to be excited when the color is deteriorated, the color misregistration can be reduced even if the output and the light emission efficiency are reduced.

(First fluorescent substance)
In the second embodiment, it is preferable that the first fluorescent material has an excitation region at least from the ultraviolet region to the short wavelength of visible light. In addition, the first fluorescent material can absorb and emit at least part of light from a semiconductor light emitting element having an emission spectrum in the ultraviolet region longer than 360 nm and the short wavelength region of visible light, In the emission spectrum, one having two or more peaks and at least two peaks complementary to each other is preferable. Further, the first fluorescent substance itself may be composed of two or more fluorescent substances having different emission spectra. Thereby, not only the light of the semiconductor light emitting element but also the light of the fluorescent material can be mixed. As such a preferable fluorescent substance as the first fluorescent substance, an element represented by M1 including at least one selected from Mg, Ca, Ba, Sr, and Zn, and at least selected from Mn, Fe, Cr, and Sn. And an alkaline earth metal halogen apatite phosphor activated with Eu having an element typified by L1.

In particular,
_{(M1 1-a-b Eu} a L1 b) 10 fluorescent substance represented by _{(PO 4)} 6 _{Q 2,}
A fluorescent substance represented by (M1 _1-a Eu _a ) ₁₀ (PO ₄ ) ₆ Q ₂ ;
A fluorescent material represented by (M1 _1-ac Eu _a Mn _b ) ₁₀ (PO ₄ ) ₆ Q ₂ ;
_{(M2 1-a-b Eu} a Ba c) 10 fluorescent substance represented by _{(PO 4)} 6 _{Q 2,}
A fluorescent substance represented by M1 _1-a Eu _a Al ₂ O ₄ ;
_{M1 1-a-b Eu a} Mn b Al fluorescent substance represented by 2 _{O 4,}
A fluorescent material represented by M3 _1-ac Eu _a Ca _c Al ₂ O ₄ ;
A fluorescent material represented by M4 _1-a Eu _a MgAl ₁₀ O ₁₇ ;
A fluorescent material represented by M4 _1-a Eu _a Mg _1-b Mn _b Al ₁₀ O ₁₇ ;
A fluorescent material represented by (M1 _1-a Eu _a ) ₄ Al ₁₄ O ₂₅ ;
A fluorescent material represented by ZnS: Cu,
(Zn, Cd) S: a fluorescent material represented by Cu, Mn,
Examples thereof include a fluorescent material represented by Re ₂ O ₂ S: Eu.
However, M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, M2 is at least one selected from Mg, Ca, Sr, Zn, and M3 is selected from Mg, Ba, Sr, Zn. M4 is at least one selected from Ca, Ba, Sr, and Zn, L1 is at least one selected from Mn, Fe, Cr, and Sn, and Re is Sc, Y, La, Gd, Lu Q is at least one selected from the halogen elements F, Cl, Br, and I.

  In the above general formula, a indicating the composition ratio of the first activator Eu element is preferably 0.0001 ≦ a ≦ 0.5. The reason is that if a is less than 0.0001, the light emission luminance decreases, and even if a exceeds 0.5, the light emission luminance tends to decrease due to concentration quenching. In order to more effectively prevent a decrease in light emission luminance, a is more preferably 0.005 ≦ a ≦ 0.4, and further preferably 0.01 ≦ a ≦ 0.2. Further, b indicating the composition ratio of at least one element of Mn, Fe, Cr, and Sn is preferably 0.0001 ≦ b ≦ 0.5, more preferably 0.005 ≦ b ≦ 0.4. Yes, more preferably 0.01 ≦ b ≦ 0.3. This is because if b exceeds 0.5, the emission luminance tends to decrease due to concentration quenching.

When these first fluorescent materials emit light using a semiconductor light emitting device having a main peak near 400 nm as a semiconductor light emitting device,
_{(M1 1-a Eu a)} 10 (PO 4) 6 Q 2, M3 1-a-c Eu a Ca c Al 2 O 4, M4 1-a Eu a MgAl 10 O 17 , the light emission of blue,
_{Further, (M1 1-a Eu a} ) 4 Al 14 O 25, (M2 1-a-c Eu a Ba c) 10 (PO 4) 6 Q 2 is, emission of blue green light,
In addition, M4 _1-a Eu _a Mg _1-b Mn _b Al ₁₀ O ₁₇ , M1 _1-a Eu _a Al ₂ O ₄ , ZnS: Cu emits green light,
In addition, (Zn, Cd) S: Cu, Mn emits yellowish brown light,
Re ₂ O ₂ S: Eu emits red light,
_{Further, (M1 1-a-b} Eu a L1 b) 10 (PO 4) 6 Q 2, (M1 1-a-b Eu a Mn b) 10 (PO 4) 6 Q 2, M1 1-a-b Eu _a Mn _b Al ₂ O ₄ can each emit white light.
In the light emitting device according to the second embodiment, the second fluorescent material is used in addition to the semiconductor light emitting element and the first fluorescent material. When using the YAG-based phosphor as the second _{phosphor, (M1 1-a-b} Eu a L1 b) 10 (PO 4) 6 Q 2, emits light white.

In addition, the (M1 _1-ab Eu _a L1 _b ) ₁₀ (PO ₄ ) ₆ Q ₂ fluorescent material described as the _first fluorescent material is excited by light in the vicinity of 400 nm of the emission spectrum of the semiconductor light emitting device, It has an emission spectrum including an emission spectrum containing a red component. Therefore, when a light emitting device is composed of the first fluorescent material and the semiconductor light emitting element, white light emission with a strong red component is produced. By adding a YAG phosphor, white light emission with excellent color rendering properties is achieved. Can be.

This fluorescent material can be obtained by the following method. Phosphorus oxide, which is a constituent element of this fluorescent substance, or various compounds that can be converted into oxides by thermal decomposition and ammonium chloride are weighed in predetermined amounts, mixed in a ball mill, put in a crucible, and reduced in N ₂ and H ₂ atmospheres Baked at a temperature of 800 to 1200 ° C. for 3 to 7 hours. The obtained fired product is wet pulverized, sieved, dehydrated and dried to obtain an alkaline earth metal halogen apatite phosphor.

This fluorescent substance is produced by exciting visible light of a relatively short wavelength from ultraviolet light (for example, the main wavelength is 440 nm or less) from blue to white (for example, white in a conventional color of JIS Z8110, or The light emission color from white (which is the basic color) to red is shown.
In particular, since it can emit light efficiently and with high luminance even by ultraviolet rays having a relatively long wavelength of about 400 nm and sufficiently contains a red component, a good color rendering property with an average color rendering index Ra of 80 or more can be obtained. .

  Further, in the light emitting device of the second embodiment, the first fluorescent material that emits light by the emission spectrum from the semiconductor light emitting element as described above, and the second fluorescent material that has a different emission spectrum from the first fluorescent material and the semiconductor light emitting element. By using a fluorescent material, color rendering can be enhanced.

(Second fluorescent material)
In the light emitting device of the second embodiment, the second fluorescent material has an emission spectrum different from any of the emission spectra of the semiconductor light emitting element and the first fluorescent material. The excitation source may be a semiconductor light emitting device, a first fluorescent material, or both a semiconductor light emitting device and a first fluorescent material.
When the second fluorescent material is capable of emitting light when excited by the semiconductor light emitting element, like the first fluorescent material, it is particularly possible to distinguish between the first fluorescent material and the second fluorescent material. However, in the second embodiment, as will be described later, a fluorescent material that can be excited by the semiconductor light emitting element and can emit light is distinguished from the first fluorescent material. The name has been changed for convenience.

  When a semiconductor light-emitting element is used as an excitation source, the half-value width of the emission spectrum of the excitation source is narrow, so that the fluorescent materials that can emit light using this as an excitation source are limited. In addition, when used for illumination as white light emission, there is a disadvantage that color rendering properties are poor. That is, using a semiconductor light emitting device capable of emitting blue light and a fluorescent material that emits light of a complementary color tone, a white color is obtained by mixing the blue light emission of the light emitting device and the yellow light emission of the fluorescent material. Can emit light. As described above, white light emission is sufficiently possible by mixing the light emission of the light emitting element and the light emission of the fluorescent material, but in this case, since it does not have a red light emitting component, it is used as illumination. In some cases, the light emission lacks redness and has low color rendering properties.

  However, in the light emitting device of the second embodiment, the color rendering properties can be dramatically improved by using the second fluorescent material together with the first fluorescent material. As the second fluorescent material, it is preferable to use a material that is excited by light from the semiconductor light-emitting element and can emit light efficiently, like the first fluorescent material. Moreover, what is excited by the light from the first fluorescent material can also be used. In this case, light can be emitted efficiently by using the main peak of the first fluorescent substance as an excitation source. However, since the first phosphor described above has a wide half-value width as compared with the semiconductor light emitting element, it has a broad emission spectrum with respect to the sharp emission spectrum of the semiconductor light emitting element. Therefore, light having a wavelength other than the main peak of the first fluorescent material may be used to be excited by the light.

The second fluorescent material can be excited by light emission from the semiconductor light emitting element and also excited by light emission from the first fluorescent material. As described above, a fluorescent material capable of emitting red light as a first fluorescent material, such as a white light having a small reddish component consisting of a semiconductor light emitting device capable of emitting blue light and a YAG fluorescent material excited thereby, for example, When (CaEuMn) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor is used, white light emission having a reddish component and excellent in color rendering is obtained.

A specific example of the second fluorescent material is an yttrium aluminum oxide fluorescent material activated with cerium. Specific examples thereof include YAlO ₃ : Ce, Y ₃ Al ₅ O ₁₂ : Ce (YAG: Ce), Y ₄ Al ₂ O ₉ : Ce, and a mixture thereof. Furthermore, at least one of Ba, Sr, Mg, Ca, and Zn may be included. Moreover, by containing Si, the reaction of crystal growth can be suppressed and the particles of the fluorescent material can be aligned.

  In this specification, the yttrium / aluminum oxide phosphor activated by Ce is to be interpreted in a broad sense, and a part or all of yttrium is selected from the group consisting of Lu, Sc, La, Gd and Sm. Or a part or all of aluminum is used in a broad sense including a phosphor having a fluorescent action in which any one or both of Ba, Tl, Ga, and In are substituted.

More specifically, the general formula _{(Y z Gd 1-z)} 3 Al 5 O 12: Ce ( where, 0 <z ≦ 1) photoluminescent phosphor and the general formula represented by _{(Re 1-a Sm a)} 3 Re ₅ O ₁₂ : Ce (where 0 ≦ a <1, 0 ≦ b ≦ 1, Re is at least one selected from Y, Gd, La, and Sc, and Re ′ is selected from Al, Ga, and In) At least one kind of photoluminescent phosphor.
Since this fluorescent material has a garnet structure, it is resistant to heat, light, and moisture, and the peak of the excitation spectrum can be made around 450 nm. In addition, the emission peak is in the vicinity of 580 nm and has a broad emission spectrum that extends to 700 nm.

  Further, the photoluminescence phosphor can increase the excitation light emission efficiency in a long wavelength region of 460 nm or more by containing Gd (gadolinium) in the crystal. As the Gd content increases, the emission peak wavelength shifts to a longer wavelength, and the entire emission wavelength also shifts to the longer wavelength side. That is, when a strong reddish emission color is required, it can be achieved by increasing the amount of Gd substitution. On the other hand, as Gd increases, the emission luminance of photoluminescence by blue light tends to decrease. Furthermore, in addition to Ce, Tb, Cu, Ag, Au, Fe, Cr, Nd, Dy, Co, Ni, Ti, Eu, and the like can be contained as desired.

Moreover, in the composition of the yttrium / aluminum / garnet phosphor having a garnet structure, the emission wavelength is shifted to the short wavelength side by replacing a part of Al with Ga. Further, by substituting part of Y in the composition with Gd, the emission wavelength is shifted to the longer wavelength side.
When substituting a part of Y with Gd, it is preferable that the substitution with Gd is less than 10%, and the Ce content (substitution) is 0.03 to 1.0. If the substitution with Gd is less than 20%, the green component is large and the red component is small. However, by increasing the Ce content, the red component can be supplemented and a desired color tone can be obtained without lowering the luminance. With such a composition, the temperature characteristics are good and the reliability of the light emitting diode can be improved. In addition, when a photoluminescent phosphor adjusted to have a lot of red components is used, a light emitting device capable of emitting an intermediate color such as pink can be configured.

  Such a photoluminescent phosphor can be produced by the following procedure. First, an oxide or a compound that easily becomes an oxide at a high temperature is used as a raw material for Y, Gd, Al, and Ce, and these are sufficiently mixed in a stoichiometric ratio to obtain a raw material. Alternatively, a mixed raw material obtained by mixing a coprecipitation oxide obtained by firing a solution obtained by coprecipitation of a solution obtained by dissolving a rare earth element of Y, Gd, and Ce in an acid in a stoichiometric ratio with oxalic acid and aluminum oxide. Get. A suitable amount of fluoride such as barium fluoride or ammonium fluoride is mixed as a flux and packed in a crucible, and fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a fired product, and then fired. The product can be obtained by ball milling in water, washing, separating, drying and finally passing through a sieve.

In the second embodiment, the photoluminescent phosphor used as the second fluorescent material may be a mixture of yttrium, aluminum and garnet phosphors activated with two or more kinds of cerium.
The preferable range of the particle size of the first and second fluorescent materials is the same as that described in the first embodiment, and the reason for setting the range is also the same.
The particle diameter measurement method is the same as that in the first embodiment.

In the second embodiment, the glass window portion of the lid is preliminarily made of, for example, (Ca _0.96 Eu ₀ as a first fluorescent substance) with respect to a slurry composed of 90 wt% nitrocellulose and 10 wt% γ-alumina. _.01 Mn _0.03 ) ₁₀ (PO ₄ ) ₆ Cl ₂ and cerium activated (YAG: Ce) as the second fluorescent material, applied to the back surface of the light-transmitting window of the lid, 220 ° C. The color conversion member is formed by heating and curing at 30 minutes.

Modified example.
Although the light emitting device according to the embodiment of the present invention has been described above, the present invention can be variously modified as follows.
In the present invention, various places can be selected as the place where the fluorescent material is disposed in consideration of the positional relationship with the light emitting element and the structure of the light emitting element.
For example, in the first and second embodiments, the color conversion member 80 is formed inside the window portion 7, but may be formed on the side surface of the concave portion of the package 5 as indicated by reference numeral 81 in FIG. 10. In this case, the p-side ohmic electrode of the LED chip 1 is not translucent, but is configured to emit light from the side surface of the LED chip 1 as an electrode that reflects light emitted from the light emitting layer into the semiconductor. .

Moreover, you may make it contain a fluorescent substance in the die-bonding material which die-bonds a light emitting element, and may make it contain in the molding material which coat | covers a light emitting element.
As described above, in the present invention, the fluorescent material may be disposed away from the light emitting element, or may be directly placed on the light emitting element.
In Embodiments 1 and 2, the color conversion member 80 is formed using nitrocellulose. However, the present invention is not limited to this, and the color conversion member containing a fluorescent substance can be formed of various binders such as a resin that is an organic material and glass that is an inorganic material. When an organic substance is used as the binder, a transparent resin having excellent weather resistance such as an epoxy resin, an acrylic resin, or silicone is suitable as a specific material. In particular, silicone is preferable because it is excellent in reliability and can improve the dispersibility of the fluorescent material.

Moreover, an inorganic substance can also be used as a binder. In this case, as a specific method, a sedimentation method, a sol-gel method, or the like can be used. For example, a phosphor, silanol (Si (OEt) ₃ OH), and ethanol are mixed to form a slurry. After the slurry is discharged from a nozzle, the silanol is converted into SiO ₂ by heating at 300 ° C. for 3 hours. By doing so, the fluorescent substance can be fixed to a desired place. In particular, when a fluorescent material is attached to the window portion, it is preferable to use an inorganic material having a thermal expansion coefficient close to that of the window portion, because the fluorescent material can be satisfactorily adhered to the window portion.

Further, an inorganic binder can be used as a binder. The binder is so-called low-melting glass, and is preferably a fine particle and very stable with little absorption with respect to radiation in the ultraviolet to visible region. An alkaline earth borate which is a fine particle obtained by a precipitation method is suitable for satisfying this condition.
In addition, when attaching a fluorescent substance having a large particle size, a binder that has a high melting point and can be made into an ultrafine powder, such as silica, alumina, or a fine particle size alkaline earth metal pyrophosphate obtained by precipitation. Preference is given to using salts, orthophosphates and the like. These binders can be used alone or mixed with each other.

  Here, a method of applying the binder will be described. As the binder, in order to sufficiently enhance the binding effect, it is preferable to use a binder slurry in which a wet pulverized binder is dispersed in a vehicle to form a slurry. A vehicle is a high viscosity solution obtained by dissolving a small amount of a binder in an organic solvent or deionized water. For example, an organic vehicle can be obtained by adding 1 wt% of nitrocellulose as a binder to butyl acetate as an organic solvent.

  A fluorescent substance is contained in the binder slurry thus obtained to prepare a coating solution. For example, the amount of the slurry in the coating solution is about 1 to 3% wt of the binder in the slurry with respect to the amount of the fluorescent substance in the coating solution. It is preferable that the amount of the binder added is small. The coating solution thus adjusted is applied to the back surface of the window portion. After that, hot air or hot air is blown to dry. Finally, baking is performed at a temperature of 400 ° C. to 700 ° C., and the vehicle is scattered to adhere a fluorescent material layer as a color conversion member to a desired place with a binder.

(Diffusion agent)
Further, in the present invention, a diffusing agent may be contained in addition to the fluorescent material. As a specific diffusing agent, barium titanate, titanium oxide, aluminum oxide, silicon oxide or the like is preferably used. As a result, a light emitting device having good directivity can be obtained.
Here, in this specification, the diffusing agent refers to those having a center particle diameter of 1 nm or more and less than 5 μm. A diffusing agent having a particle size of 1 μm or more and less than 5 μm can diffuse irregularly the light from the fluorescent material and suppress color unevenness that tends to occur when a fluorescent material having a large particle size is used. On the other hand, a diffusing agent of 1 nm or more and less than 1 μm has a low interference effect with respect to the light wavelength from the light emitting element, but can increase the resin viscosity without lowering the luminous intensity. This makes it possible to disperse the fluorescent substance in the resin almost uniformly in the syringe and maintain the state when placing the fluorescent substance-containing resin by potting or the like, and the particle size is relatively difficult to handle. Even when a large fluorescent material is used, it is possible to produce with high yield. Thus, the action of the diffusing agent in the present invention varies depending on the particle size range, and can be selected or combined according to the method of use.

(Filler)
Furthermore, in the present invention, the color conversion member may contain a filler in addition to the fluorescent material. The specific material is the same as that of the diffusing agent, but the diffusing agent has a central particle size different from that of the diffusing agent. When the filler having such a particle size is contained in the translucent resin, the chromaticity variation of the light emitting device is improved by the light scattering action, and the thermal shock resistance of the translucent resin can be enhanced. As a result, even when used at high temperatures, it is possible to prevent disconnection of the wire electrically connecting the light emitting element and the external electrode, peeling of the bottom surface of the light emitting element and the bottom surface of the recess of the package, and the like. A high light emitting device is obtained. Furthermore, the fluidity of the resin can be adjusted to be constant for a long time, and a sealing member can be formed at a desired location, enabling mass production with a high yield.

The filler preferably has a particle size and / or shape similar to that of the fluorescent material. Here, in this specification, the similar particle size means a case where the difference in the central particle size of each particle is less than 20%, and the similar shape means an approximate degree of each particle size with a perfect circle. This represents a case where the difference in the value of circularity (circularity = peripheral length of a perfect circle equal to the projected area of the particle / perimeter length of the projected particle) is less than 20%. By using such a filler, the fluorescent material and the filler interact with each other, and the fluorescent material can be favorably dispersed in the resin, thereby suppressing color unevenness.
For example, both the fluorescent material and the filler have a center particle size of 15 μm to 50 μm, more preferably 20 μm to 50 μm. By adjusting the particle diameter in this manner, the particles can be arranged with a preferable interval. As a result, a light extraction path is ensured, and the directivity can be improved while suppressing a decrease in luminous intensity due to filler mixing.

Moreover, in this invention, the fluorescent material represented by the following formula | equation (1)-Formula (6) may further be included.

  Here, in the formulas (1) to (6), Rf1, Rf2, Rf3, Rf4 and Rf5 are the same or different and are C1 to C22 aliphatic groups containing no hydrogen atom, and aromatic groups containing no hydrogen atom. Or the heterocyclic group which does not contain a hydrogen atom is shown.

As C1-C22 aliphatic groups containing no hydrogen atom:
A perhalogenated alkyl group having a straight chain or a branch, such as a perfluoroalkyl group (CnF2n + 1; n = 1 to 22), a perchloroalkyl group (CnCl2n + 1; n = 1 to 22), specifically , Trichloromethyl, trifluoromethyl, pentachloroethyl, pentafluoroethyl, heptachloropropyl, heptafluoropropyl, heptachloroisopropyl, heptafluoroisopropyl, nonachlorobutyl, nonafluorobutyl, nonachloroisobutyl, nonafluoroisobutyl, undeca Chloropentyl, undecafluoropentyl, undecachloroisopentyl, undecafluoroisopentyl, tridecachlorohexyl, tridecafluorohexyl, tridecachloroisohexyl, tridecafluoroisohexyl, pentadecachloroheptyl, pepe Tadecafluoroheptyl, pentadecachloroisoheptyl, pentadecafluoroisoheptyl, heptadecachlorooctyl, heptadecafluorooctyl, heptadecachloroisooctyl, heptadecafluoroisooctyl, nonadecachlorononyl, nonadecafluorononyl, nona Decachloroisononyl, Nonadecafluoroisononyl, Henicosachlorodecyl, Henicosafluorodecyl, Henicosachloroisodecyl, Henicosafluoroisodecyl, Tricosachloroundecyl, Tricosafluoroundecyl, Trico Sachloroisoundecyl, tricosafluoroisoundecyl, pentacosachlorododecyl, pentacosafluorododecyl, pentacosachloroisododecyl, pentacosafluoroisododecyl, heptacosachlorotridec Le, hepta Cosa fluoro tridecyl, hepta Cosa chloro isotridecyl, hepta Cosa fluoro isotridecyl like;
Perfluoroalkenyl group (perfluorovinyl group, perfluoroallyl group, perfluorobutenyl group, etc.), C2-C22 perhalogenated alkenyl group having a straight chain or a branch such as perchloroalkenyl group, preferably trifluoro Ethynyl, trichloroethynyl, pentafluoropropenyl, pentachloropropenyl, heptafluorobutenyl, heptachlorobutenyl and the like;
A C2 to C22 perhalogenated alkynyl group having a straight chain or a branch, such as a perfluoroalkynyl group or a perchloroalkynyl group;
Perfluorocycloalkyl group (CnF2n-1; n = 3-22, preferably 3-8, more preferably 3-6), perchlorocycloalkyl group (CnCl2n-1; n = 3-22, preferably 3 8, more preferably 3-6) perhalogenated cycloalkyl groups, preferably pentachlorocyclopropyl, pentafluorocyclopropyl, heptachlorocyclobutyl, heptafluorocyclobutyl, nonachlorocyclopentyl, nonafluoro Cyclopentyl, undecachlorocyclohexyl, undecafluorocyclohexyl, tridecachlorocycloheptyl, tridecafluorocycloheptyl, pentadecachlorocyclooctyl, pentadecafluorocyclooctyl and the like;
C 3 -C 22, preferably C 3 -C 8, more preferably C 3 -C 6 perhalogenated cycloalkenyl group such as perfluorocycloalkenyl group (perfluorocyclopentenyl group, perfluorocyclohexenyl group, etc.), perchlorocycloalkenyl group, etc. And perhalogenated aralkyl groups such as a perfluorobenzyl group and a perfluorophenethyl group.

Examples of the aromatic group in the aromatic group not containing a hydrogen atom include phenyl, naphthyl, anthranyl, phenanthryl, pyrenyl and the like;
Examples of the heterocyclic group in the heterocyclic group not containing a hydrogen atom include pyridyl, thienyl, pyrrolyl, pyrimidinyl, quinolyl, isoquinolyl, benzimidazolyl, benzopyranyl, indolyl, benzofuranyl, imidazolyl, pyrazolyl, biphenyl, etc., and these aromatic groups and All the hydrogen atoms in the heterocyclic group are halogen atoms such as fluorine atom, chlorine atom and bromine atom, nitro group, C1-C4 perhalogenated alkyl group (trifluoromethyl etc.), C1-C4 perhalogenated alkoxy. Groups (such as trifluoromethoxy), C2 to C5 perhalogenated alkylcarbonyl groups (such as trifluoroacetyl), C1 to C4 perhalogenated alkylenedioxy groups (such as difluoromethylenedioxy), C2 to C5 perhalogen Alkenyl group (perhalogen) Vinyl halide, etc.), perhalogenated phenoxy groups, C2 to C22 perhalogenated alkylcarbonyloxy and the like. Specific examples of the aromatic group not containing a hydrogen atom include a perfluorophenyl group, a perchlorophenyl group, a perfluoronaphthyl group, a perchloronaphthyl group, a perfluoroanthranyl group, a perchloroanthranyl group, a perfluorophenanthryl group, Examples include a perchlorophenanthryl group, and examples of the heterocyclic group not containing a hydrogen atom include a perhalogenated 2-pyridyl group.

One or more of the halogen atoms bonded to the aromatic ring or heterocyclic ring of the perhalogenated aromatic group, perhalogenated heterocyclic group or perhalogenated aralkyl group is cyano, nitro, nitroso, C1-C4 perhalogenated. It may be substituted with a substituent not containing a hydrogen atom such as alkoxy, C2 to C5 perhalogenated alkoxycarbonyl, C2 to C22 perhalogenated alkylcarbonyloxy and the like.
In addition, between the C—C single bond at any position of the C 1 -C 22 perhalogenated alkyl group, the C 2 -C 22 perhalogenated alkenyl group, and the C 2 -C 22 perhalogenated alkynyl group, —O—, —COO—, — One or a plurality of CO- may be interposed to form an ether, ester or ketone structure.

Examples of the rare earth element represented by M include lanthanum series elements such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. Nd, Eu, Tb and Yb.
X1 and X2 are group IVA atoms such as C, Si, Ge, Sn and Pb, group VA atoms excluding nitrogen such as P, As, Sb and Bi, and group VIA excluding oxygen such as S, Se, Te and Po. Indicates any atom, preferably C, S, P or Se, more preferably C or S.
X3 is any one of group IVA atoms such as Si, Ge, Sn and Pb, group VA atoms excluding nitrogen such as P, As, Sb and Bi, and group VIA atoms excluding oxygen such as S, Se, Te and Po. And preferably S.
Y represents CZ '(Z' is the same as above), N, P, As, Sb or Bi, preferably CZ '(Z' is the same as above), N or P.
Z 'represents a deuterium atom, a halogen atom or a C1 to C22 aliphatic group containing no hydrogen atom, preferably a deuterium atom or a C1 to C22 perhalogenated alkyl group having a straight or branched chain.
Z ″ represents H or Z ′.
n1 represents 2 or 3, preferably 3.
n2 represents 2 to 4, preferably 2 or 3, in particular 3.
n3, n4, and n5 are 0 or 1. In particular, when X1, X2 or X3 is S, n3, n4 or n5 is preferably 1, and when X1 or X2 is C, n3 or n4 is 0.
The fluorescent substances represented by (1) to (6) are used in addition to the first fluorescent substance as the fluorescent substance in the light emitting device of the first embodiment, for example, the light emitting element of the second embodiment, for example. The fluorescent material in can be used as the first fluorescent material or the second fluorescent material.

  Examples according to the present invention will be described in detail below.

In Example 1, a surface-mounted light emitting device as shown in FIG. 2 is formed. The LED chip 1 uses a nitride semiconductor element having a 375 nm InAlGaN semiconductor having an emission peak in the ultraviolet region as a light emitting layer. More specifically, the LED chip 1 flows a TMG (trimethylgallium) gas, TMI (trimethylindium) gas, nitrogen gas, and a dopant gas together with a carrier gas on a cleaned sapphire substrate, and forms a nitride semiconductor by MOCVD. To make it. At this time, a layer to be an n-type nitride semiconductor or a p-type nitride semiconductor is formed by switching between SiH ₄ and Cp ₂ Mg as dopant gases.
The element structure of the LED chip 1 is an n-type GaN layer that is an undoped nitride semiconductor on a sapphire substrate, a GaN layer that forms an n-type contact layer by forming an Si-doped n-type electrode, and an undoped nitride semiconductor. One set of an n-type GaN layer, an AlGaN layer containing Si serving as an n-type cladding layer, an AlInGaN layer constituting a well layer as a light emitting layer, and an AlInGaN layer serving as a barrier layer having a higher Al content than the well layer And a multi-quantum well structure in which five sets are stacked. An AlGaN layer, a GaN layer that increases electrostatic withstand voltage, and a GaN layer that is a p-type contact layer doped with Mg are sequentially stacked on the light emitting layer as a p-type cladding layer doped with Mg. A GaN layer is formed on the sapphire substrate at a low temperature to serve as a buffer layer. The p-type semiconductor is annealed at 400 ° C. or higher after film formation.

This will be described in detail with reference to FIGS. 11A to 11E are diagrams illustrating a manufacturing process of a semiconductor light emitting element. In the case of manufacturing a semiconductor light emitting device, a SiO ₂ film 30 serving as an etching mask is formed on the sapphire substrate 10 as shown in FIG. 11A.
Next, using a photomask having a regular triangle of 10 μm per side, aligning the photomask so that one side of the regular triangle is perpendicular to the orientation flat, and each side of the regular triangle is a (1-100) plane of sapphire, (01 −10) plane, (−1010) plane, that is, substantially parallel to the M plane, and after etching the SiO ₂ film 30 and the sapphire substrate 10 by about 1 μm by RIE as shown in FIGS. 11B and 11C, FIG. When the SiO ₂ film 30 is removed as shown in FIG. 11D, a repeated pattern of the recesses 20 is formed on the surface portion of the sapphire substrate 10.
Here, the bar (-) in the parentheses means a bar to be placed on a number located immediately after the bar.

Next, after a buffer layer made of GaN is grown on the sapphire substrate at a temperature of 500 ° C. to a thickness of 200 mm, the temperature is raised to 1050 ° C., and an undoped GaN layer is grown to a thickness of 5 μm. Note that the film thickness to be grown is not limited to 5 μm, and it is desirable that the film is grown to a film thickness thicker than the buffer layer and adjusted to a film thickness of 10 μm or less. Next, after the growth of the undoped GaN layer, the wafer is taken out of the reaction vessel, a striped photomask is formed on the surface of the GaN layer, and a SiO 2 having a stripe width of 15 μm and a stripe interval (window) of 5 μm is formed by a CVD apparatus. _A mask made of ₂ is formed to a thickness of 0.1 μm. After forming the mask, the wafer is set again in the reaction vessel, and undoped GaN is grown to a thickness of 10 μm at 1050 ° C. The crystal defect of the undoped GaN layer is 10 ¹⁰ / cm ² or more, but the crystal defect of the GaN layer is 10 ⁶ / cm ² or more.

(N-type contact layer, n-type gallium nitride compound semiconductor layer)
Next, an n-type contact layer and an n-type gallium nitride compound semiconductor layer are formed. First, an n-type contact layer made of GaN doped with Si at 4.5 × 10 ¹⁸ / cm ³ is grown at a thickness of 2.25 μm at 1050 ° C. using silane gas as the source gas TMG, ammonia gas, and impurity gas. Let Next, the silane gas alone is stopped, TMG and ammonia gas are used at 1050 ° C., an undoped GaN layer is grown to a thickness of 75 mm, and then silane gas is added at the same temperature to add Si to 4.5 × 10 ¹⁸ / A GaN layer doped with cm ³ is grown to a thickness of 25 mm. In this manner, a pair consisting of an A layer made of 75 ア ン undoped GaN and a 25 Ｂ B layer having a Si doped GaN layer is grown. Then, 25 pairs are laminated to a thickness of 2500 mm, and an n-type gallium nitride compound semiconductor layer made of a multilayer film having a superlattice structure is grown.

(Active layer)
Next, a barrier layer made of undoped GaN is grown to a thickness of 250 mm, and then the temperature is raised to 800 ° C., and a well layer made of undoped InGaN is grown to a thickness of 30 mm using TMG, TMI, and ammonia. . Then, seven barrier layers and six well layers are alternately laminated in the order of barrier + well + barrier + well + ... + barrier to grow an active layer having a multiple quantum well structure with a total thickness of 1930 mm. Let

(P-type layer)
Next, a p-type layer including a p-side multilayer clad layer and a p-type contact layer is formed. First, using TMG, TMA, ammonia, Cp ₂ Mg (cyclopentadienyl magnesium) at a temperature of 1050 ° C., Mg-doped 1 × 10 ²⁰ / cm ³ doped p-type Al _0.2 Ga _0.8 N 3 nitride semiconductor layer is grown to a thickness of 40 mm, subsequently the temperature is set to 800 ° C., TMG, TMI, ammonia, Cp ₂ Mg are used, and Mg is doped with 1 × 10 ²⁰ / cm ³ _{. A} fourth nitride semiconductor layer made of ₀₃ Ga _0.97 N is grown to a thickness of 25 mm. Then, these operations are repeated, and five layers are alternately stacked in the order of 3 + 4, and finally, the third nitride semiconductor layer is grown to a thickness of 40 mm. A side multilayer clad layer is grown to a thickness of 365 mm. Subsequently, at 1050 ° C., a p-side contact layer made of p-type GaN doped with 1 × 10 ²⁰ / cm ^{3 of} Mg using TMG, ammonia, and Cp 2 Mg is grown to a thickness of 700 mm.

After the completion of the reaction, the temperature is lowered to room temperature, and the wafer is annealed in a reaction vessel at 700 ° C. in a nitrogen atmosphere to further reduce the resistance of the p-type layer.
Since the GaN lattice grows by 30 degrees with respect to the sapphire substrate 10, the repetitive pattern of the recesses 20 formed on the sapphire substrate 10 is the GaN A-plane (11-20), (1-210), (-2110) plane. GaN growth stability planes (1-100), (01-10), (-1010) have apexes, and GaN growth stability planes (1-100), (01-10) , (-1010), that is, a polygon having no straight line parallel to the M plane.
Next, the surface of each pn contact layer is exposed on the same side of the nitride semiconductor on the sapphire substrate by etching. Specifically, the wafer is taken out of the reaction vessel, a mask having a predetermined shape is formed on the surface, and etching is performed from the p-type gallium nitride compound semiconductor layer side with an RIE (reactive ion etching) apparatus, thereby forming an n-type contact layer. To expose the surface.

(Translucent p electrode, pedestal electrode, n electrode)
Positive and negative pedestal electrodes are formed on each contact layer by sputtering. A metal thin film is formed on the entire surface of the p-type nitride semiconductor as a translucent electrode, and then a pedestal electrode is formed on a part of the translucent electrode. Specifically, after etching, a light-transmitting p-electrode (Ni / Au = 60/50) having a thickness of 110 mm so as to cover almost the entire surface of the p-type layer, and a film thickness of 0.5 μm on the p-electrode. A pedestal electrode made of Au and having three extended conductor portions is formed along the side at the corner of the light emitting element. On the other hand, an n electrode containing W and Al is formed on the surface of the n-side contact layer exposed by etching so as to face the pedestal electrode.
Next, in order to form an n-electrode, the Mg-doped GaN to the p-type semiconductor layer, the active layer, and a part of the n-type semiconductor layer are etched to expose the Si-doped GaN layer.
Next, using a photomask patterned with a regular triangle having a side of 5 μm and filled with the regular triangle as shown in FIG. 12 per unit area most densely, a translucent material made of Ni / Au is used. A p-electrode is formed in the shape of an equilateral triangle on almost the entire surface of the p-type semiconductor layer.
Furthermore, a p-pad electrode made of Pt / Au is formed on the light-transmitting p-electrode at a position facing the exposed surface of the n-type semiconductor layer, and an n-electrode made of Ti / Al on the exposed surface of the n-type semiconductor layer and An n-pad electrode made of Pt / Au is formed.

Finally, the wafer is chipped into a square shape to obtain a semiconductor light emitting device.
The light emitting output of the semiconductor light emitting device thus obtained was improved due to the property that light near the periphery of the p electrode was stronger than other portions.
As a different embodiment, the processing of the substrate and the lamination from the n-type semiconductor layer to the p-type semiconductor layer are the same as described above.

Next, in order to form an n-electrode, the Mg-doped GaN to the p-type semiconductor layer, the active layer, and a part of the n-type semiconductor layer are etched to expose the Si-doped GaN layer.
Next, using a photomask that is a regular triangle having a side of 5 μm and in which the regular triangle as shown in FIG. 12 is filled most densely per unit area, a p-electrode 104 made of Rh is formed as p It is formed in the shape of an equilateral triangle on almost the entire surface of the type semiconductor layer.
Further, a p-pad electrode 105 made of Pt / Au is formed on the p-electrode 104 at a position facing the exposed surface of the n-type semiconductor layer, and an n-electrode made of Ti / Al and Pt / Au are formed on the exposed surface of the n-type semiconductor layer. An n-pad electrode 103 made of Au is formed.
Finally, the wafer is chipped to obtain a semiconductor light emitting device. FIG. 12 shows the light emitting element as viewed from above.

  The semiconductor light-emitting device obtained thereby utilizes the property that the periphery of the p-electrode shines stronger than the other parts, and further uses a material that highly reflects the emission wavelength for the electrode to absorb light at the electrode. As a result, the light emission output was further improved.

  On the other hand, a Kovar package is used as a housing of the light emitting device. The Kovar package includes a base portion having a concave portion at the center and Kovar lead electrodes inserted and fixed in an insulating and airtight manner on both sides of the concave portion. A Ni / Ag layer is provided on the surface of the package and the lead electrode.

  An LED chip is die-bonded with an Ag—Sn alloy in the recess of the package thus configured. Next, the respective electrodes of the die-bonded LED chip and the respective lead electrodes exposed from the bottom of the package recess are electrically connected by Ag wires.

Next, SrHPO ₄ , SrCO ₃ , Eu ₂ O ₃ , MnCO ₃ , NH ₄ Cl are used as the fluorescent material as raw materials (Sr _0.96 , Eu _0.01 , Mn _0.03 ) ₁₀ (PO ₄ ) ₆ Cl Adjust and mix so that the composition ratio is ₂ . (SrHPO ₄ : 1000 g, SrCO ₃ : 482.4 g, Eu ₂ O ₃ : 16.0 g, MnCO ₃ : 35.2 g, NH ₄ Cl: 116.5 g)
The raw materials are weighed and mixed thoroughly by a dry method using a mixer such as a ball mill. This mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, heated to 1200 ° C. at 960 ° C./hr in a reducing atmosphere of N ₂ and H ₂ , and fired at a constant temperature part 1200 ° C. for 3 hours. The obtained fired product is pulverized, dispersed, sieved, separated, washed with water, and dried in water to obtain the desired phosphor powder.

The obtained fluorescent material and SiO ₂ filler or diffusing agent are contained in a slurry composed of 90 wt% nitrocellulose and 10 wt% γ-alumina, applied to the back of the transparent window portion of the lid, and 220 ° C. for 30 minutes. A color conversion member is formed by heat curing. After sufficiently removing moisture in the recess of the package, the recess is sealed with a Kovar lid having a glass window at the center, and seam welding is performed to form a light emitting device. The chromaticity coordinates of such a light emitting device can be (x, y) = (0.384, 0.332).

(Comparative Example 1)
Instead of the fluorescent material of the present invention, in order to produce the same chromaticity, the emission color is blue BaMg ₂ Al ₁₆ O ₂₇ : Eu, the emission color is green BaMg ₂ Al ₁₆ O ₂₇ : Eu: Mn, and the emission color is red. The Y ₂ O ₂ S: Eu was mixed to make the same chromaticity as that of Example 1, and the light emitting device was configured in the same manner as in Example 1 except that the chromaticity was 100%. Assuming that the light emission luminance of Comparative Example 1 is 100%, the light emitting device of Example 1 with excitation of 400 nm is about 237%. A light emitting device by excitation at 365 nm emits reddish white, and the emission luminance is about 157%.
In Examples 2 to 17, light-emitting devices were fabricated in the same manner as in Example 1 except that the fluorescent material in Example 1 was replaced with the fluorescent material shown in Table 1.
The results are shown in Table 2.

Table 1

Here, in Example _2-8, it was adjusted to a fluorescent substance having the composition shown in Table 1 by changing the amount of SrCO 3, MnCO ₃ and _Eu 2 _{O 3.}
In Examples 9 to 16, using _{CaHPO 4, CaCO 3, Eu 2} O 3, MnCO 3, NH 4 Cl as a starting material was adjusted so as to have the composition of the fluorescent material shown in Table 1.
For example, in Example 9, the above raw materials were used so that CaHPO ₄ : 1000 g, CaCO ₃ : 441.4 g, Eu ₂ O ₃ : 21.6 g, MnCO ₃ : 47.5 g, NH ₄ Cl: 157.3 g Weigh and dry thoroughly using a mixer such as a ball mill. Then, the mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, heated to 1200 ° C. at 960 ° C./hr in a reducing atmosphere of N ₂ and H ₂ , and fired at 1200 ° C. for 3 hours. . The obtained fired product is pulverized, dispersed, sieved, separated, washed with water, and dried in water to obtain the desired phosphor powder.
In Examples 10 to 16, except for changing the amount of CaCO _3, MnCO ₃ of Example 9 was prepared a fluorescent material in the same manner as in Example 9.
Further, in Example 17, BaHPO ₄ , BaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , and NH ₄ Cl were used as raw materials, and the composition shown in Table 1 was adjusted.

Specifically, the raw materials were weighed so that BaHPO ₄ : 1000 g, BaCO ₃ : 507.5 g, Eu ₂ O ₃ : 12.6 g, MnCO ₃ : 27.7 g, NH ₄ Cl: 91.7 g Mix thoroughly by a dry method using a mixer such as a ball mill. This mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, heated to 1200 ° C. at 960 ° C./hr in a reducing atmosphere of N ₂ and H ₂ , and fired at a constant temperature part 1200 ° C. for 3 hours. The obtained fired product is pulverized, dispersed, sieved, separated, washed with water, and dried in water to obtain the desired phosphor powder.

Table 2

Here, the 400 nm excitation luminance shown in Table 2 indicates the ratio of the 400 nm excitation luminance of the example to the 400 nm excitation luminance of the comparative example, and the 365 nm excitation luminance is the 365 nm excitation luminance of the example with respect to the 365 nm excitation luminance of the comparative example. Shows the percentage. The same applies to the tables showing the characteristics of other examples.
In Examples 18 to 25, light emitting devices were produced in the same manner as in Example 1 except that the fluorescent material in Example 1 was replaced with the fluorescent material shown in Table 3.
The results are shown in Table 4.

Table 3

Here, in Examples 18 to 25, fluorescent materials were prepared so as to have the compositions shown in Table 3 using SrHPO ₄ , SrCO ₃ , BaCO ₃ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , and NH ₄ Cl as raw materials. did.
Specifically, in the example of Example 18, SrHPO ₄ : 1000 g, SrCO ₃ : 134.0 g, BaCO ₃ : 376.2 g, CaCO ₃ : 45.4 g, Eu ₂ O ₃ : 16.0 g, MnCO ₃ : The raw materials are weighed so as to be 35.2 g and NH ₄ Cl: 116.5 g, and thoroughly mixed by a dry method using a mixer such as a ball mill.
This mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, heated to 1200 ° C. at 960 ° C./hr in a reducing atmosphere of N ₂ and H ₂ , and fired at a constant temperature part 1200 ° C. for 3 hours. The obtained fired product is pulverized, dispersed, sieved, separated, washed with water, and dried in water to obtain the desired phosphor powder.

In Examples 19 to 25, fluorescent materials were produced in the same manner as in Example 18 except that the amounts of SrCO ₃ and MnCO ₃ were changed.
Table 4

In Examples 26 to 29, light emitting devices were produced in the same manner as in Example 1 except that the fluorescent material in Example 1 was replaced with the fluorescent material shown in Table 5.
The results are shown in Table 6.

Table 5

Table 6

Here, in Example 26, SrHPO ₄ , SrCO ₃ , BaCO ₃ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , NH ₄ Cl, SnO ₂ were used as raw materials, and the raw materials had the compositions shown in Table 5. Weigh and dry the mixture thoroughly with a mixer such as a ball mill. The mixed raw material is packed in a crucible made of SiC, quartz, alumina or the like, heated in a reducing atmosphere of N2, H2, and fired. The obtained fired product was pulverized, dispersed, sieved, separated, washed with water, and dried in water to obtain a target phosphor powder.

In Example 27, SrHPO ₄ , SrCO ₃ , BaCO ₃ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , NH ₄ Cl, and Fe ₂ O ₃ were used as raw materials, and the raw materials had the compositions shown in Table 5. Thereafter, a fluorescent material was obtained in the same manner as in Example 26.
In Example 28, SrHPO ₄ , SrCO ₃ , BaCO ₃ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , NH ₄ Cl, and Cr ₂ O ₃ were used as raw materials, and the raw materials had the compositions shown in Table 5. Thereafter, a fluorescent material was obtained in the same manner as in Example 26.
In Example 29, SrHPO ₄ , SrCO ₃ , BaCO ₃ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ , NH ₄ Cl, and Cr ₂ O ₃ were used as raw materials, and the raw materials had the compositions shown in Table 5. Thereafter, a fluorescent material was obtained in the same manner as in Example 26.

Example 30. FIG.
In Example 30, a light emitting device is formed in the same manner as in Example 1 except that the color conversion member is configured using silicone containing 50 wt% of the same fluorescent material as in Example 1.
The light-emitting device of Example 30 can be formed with good mass productivity although the output is likely to decrease with time as compared with Example 1.

Example 31.
In Example 31, a light emitting device is formed in the same manner as in Example 1 except that the color conversion member is formed by applying silica-gel containing 50 wt% of the same fluorescent substance as in Example 1.
The light emitting device of Example 31 can obtain the same effects as those of Example 1.
Further, in Examples 32 to 43, light emitting devices were produced in the same manner as in Example 1 except that the fluorescent material of Example 1 was replaced with the fluorescent material shown in Table 7.
The results are shown in Table 8.

Table 7

Here, the fluorescent materials of Examples 32-43 are produced as follows.
Fluorescent material of Example 32, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing the half of NH 4 _Cl in NH 4 _Br.
The fluorescent material of Example 33 was adjusted by changing all of NH ₄ Cl to NH ₄ Br among the raw materials used when the fluorescent material of Example 7 was produced.
Fluorescent material of Example 34, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing the half of NH 4 _Cl in NH 4 _F.
Fluorescent material of Example 35, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing the entire NH 4 _Cl in NH 4 _F.
Fluorescent material of Example 36, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing the half of NH 4 _Cl in NH 4 _I.
Fluorescent material of Example 37, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and _NH 4 Br.
Fluorescent material of Example 38, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and NH ₄ I.
Fluorescent material of Example 39, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing a part of _NH 4 Cl in _NH 4 Br and NH ₄ I.
Fluorescent material of Example 40, among the materials used in making the fluorescent substance of Example 7 was adjusted by changing a part of _{NH 4} Cl _NH 4 F, in _NH 4 Br and NH ₄ I.
The phosphor of Example 41 was adjusted by changing NH ₄ Cl to NH ₄ F and NH ₄ Br among the raw materials used when the phosphor of Example 7 was produced.
The phosphor of Example 42 was prepared by changing NH ₄ Cl to NH ₄ F and NH ₄ I among the raw materials used when the phosphor of Example 7 was produced.
The fluorescent material of Example 43 was adjusted by changing NH ₄ Cl to NH ₄ I and NH ₄ Br among the raw materials used when producing the fluorescent material of Example 7.

Table 8

In Examples 44 to 55, light emitting devices were produced in the same manner as in Example 1 except that the fluorescent material of Example 1 was replaced with the fluorescent material shown in Table 9.
The results are shown in Table 10.

Table 9

Here, the fluorescent materials of Examples 44 to 55 are produced as follows.
Fluorescent material of Example 44, among the materials used in making the fluorescent material of Example 15 was adjusted by changing the entire NH 4 _Cl in NH 4 _Br.
Fluorescent material of Example 46, among the materials used in making the fluorescent material of Example 15 was adjusted by changing the half of NH 4 _Cl in NH 4 _F.
Fluorescent material of Example 47, among the materials used in making the fluorescent material of Example 15 was adjusted by changing the entire NH 4 _Cl in NH 4 _F.
Phosphor of Example 48, among the materials used in making the fluorescent material of Example 15 was adjusted by changing the half of NH 4 _Cl in NH 4 _I.
Fluorescent material of Example 49, among the materials used in making the fluorescent material of Example 15 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and _NH 4 Br.
Fluorescent material of Example 50, among the materials used in making the fluorescent material of Example 15 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and NH ₄ I.
Fluorescent material of Example 51, among the materials used in making the fluorescent material of Example 15 was adjusted by changing a part of _NH 4 Cl in _NH 4 Br and NH ₄ I.
Fluorescent material of Example 52, among the materials used in making the fluorescent material of Example 15 was adjusted by changing a part of _{NH 4} Cl _NH 4 F, in NH ₄ Br and NH ₄ I.
The phosphor of Example 53 was prepared by changing NH ₄ Cl to NH ₄ F and NH ₄ Br among the raw materials used when the phosphor of Example 15 was produced.
The phosphor of Example 54 was prepared by changing NH ₄ Cl to NH ₄ F and NH ₄ I among the raw materials used when the phosphor of Example 15 was produced.
The fluorescent material of Example 55 was prepared by changing NH ₄ Cl to NH ₄ I and NH ₄ Br among the raw materials used when producing the fluorescent material of Example 15.

Table 10

In Examples 56 to 67, light emitting devices were produced in the same manner as in Example 1 except that the fluorescent material of Example 1 was replaced with the fluorescent material shown in Table 11.
The results are shown in Table 12.

Table 11

Here, the fluorescent materials of Examples 56 to 67 are prepared as follows.
Fluorescent material of Example 56, among the materials used in making the fluorescent material of Example 24 was adjusted by changing the half of NH 4 _Cl in NH 4 _Br.
Fluorescent material of Example 57, among the materials used in making the fluorescent material of Example 24 was adjusted by changing the entire NH 4 _Cl in NH 4 _Br.
Fluorescent material of Example 58, among the materials used in making the fluorescent material of Example 24 was adjusted by changing the half of NH 4 _Cl in NH 4 _F.
Fluorescent material of Example 59, among the materials used in making the fluorescent material of Example 24 was adjusted by changing the entire NH 4 _Cl in NH 4 _F.
Fluorescent material of Example 60, among the materials used in making the fluorescent material of Example 24 was adjusted by changing the half of NH 4 _Cl in NH 4 _I.
Fluorescent material of Example 61, among the materials used in making the fluorescent material of Example 24 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and _NH 4 Br.
Fluorescent material of Example 62, of the materials used in making the fluorescent material of Example 24 was adjusted by changing a part of _NH 4 Cl in NH ₄ F and NH ₄ I.
Fluorescent material of Example 63, of the materials used in making the fluorescent material of Example 24 was adjusted by changing a part of _NH 4 Cl in _NH 4 Br and NH ₄ I.
Fluorescent material of Example 64, among the materials used in making the fluorescent material of Example 24 was adjusted by changing a part of _{NH 4} Cl _NH 4 F, in _NH 4 Br and NH ₄ I.
The phosphor of Example 65 was prepared by changing NH ₄ Cl to NH ₄ F and NH ₄ Br among the raw materials used when the phosphor of Example 24 was produced.
The phosphor of Example 66 was adjusted by changing NH ₄ Cl to NH ₄ F and NH ₄ I among the raw materials used when the phosphor of Example 24 was produced.
The phosphor of Example 67 was prepared by changing NH ₄ Cl to NH ₄ I and NH ₄ Br among the raw materials used when the phosphor of Example 24 was produced.

Table 12

In Examples 68 to 77, light emitting devices were produced as follows, and the results shown in Table 13 were obtained.
Example 68.
In Example 68, Example _{9 (Ca 0.93, Eu 0.5,} Mn 0.02) 10 (PO 4) 6 C l2 to the phosphor, the emission color is green as the second phosphor SrAl ₂ A light emitting device is produced in the same manner except that O ₄ : Eu phosphor is added.
Example 69.
In Example 69, (Ca _0.93 , Eu _0.5 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor having a blue emission color as a third phosphor is added to the two types of phosphors of Example 68. A light emitting device is manufactured in the same manner except that it is used.
Example 70.
In Example 70, a light-emitting device was fabricated in the same manner except that a La ₂ O ₂ S: Eu phosphor having a red emission color as a fourth phosphor was added to the three types of phosphors of Example 69. To do.
Example 71.
In Example 71, (Sr _0.93 , Eu _0.5 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor having an emission color of blue as a third phosphor was added to the two types of phosphors of Example 68. A light-emitting device is manufactured in the same manner except that it is used.
Example 72.
In Example 72, a light-emitting device was produced in the same manner except that a La ₂ O ₂ S: Eu phosphor having a red emission color as a fourth phosphor was added to the three types of phosphors of Example 71. To do.
Example 73.
In Example 73, CaHPO ₄ , CaCO ₃ , Eu ₂ O ₃ , MnCO ₃ and NH ₄ Cl were used as raw materials (Ca _0.88 , Eu _1.0 , Mn _0.02 ) ₁₀ (PO ₄ ) ₆ Cl ₂ A phosphor obtained by adjusting and mixing the composition ratio and a Sr ₄ Al ₁₄ O ₂₅ : Eu phosphor having an emission color of blue-green as a second phosphor was used in the same manner. A light emitting device is manufactured.
Example 74.
In Example 74, except that (Ca _0.93 , Eu _0.5 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor was used as the third phosphor in addition to the two types of phosphors of Example 73. Similarly, a light emitting device is manufactured.
Example 75.
In Example 75, a light-emitting device was produced in the same manner except that a La ₂ O ₂ S: Eu phosphor having a red emission color as a fourth phosphor was added to the three types of phosphors of Example 74. To do.
Example 76.
In Example 76, (Sr _0.93 , Eu _0.5 ) ₁₀ (PO ₄ ) ₆ Cl ₂ phosphor having a blue emission color as a third phosphor is added to the two types of phosphors of Example 73. A light emitting device is manufactured in the same manner except that it is used.
Example 77.
In Example 77, a light-emitting device was manufactured in the same manner except that a La ₂ O ₂ S: Eu phosphor having a red emission color as a fourth phosphor was added to the three types of phosphors of Example 71. To do.

Table 13

In Examples 78 to 154, light emitting devices were fabricated in the same manner as in Example 1 except that the phosphors were configured using the first phosphor substance and the second two kinds of phosphor substances shown in Table 14. In Examples 78 to 154, the composition of the light emitting layer was adjusted so that the LED chip had a light emission wavelength of 400 nm.
In the column of the first fluorescent material in Table 14, for example, the column described as Example 1 indicates that the same fluorescent material as in Example 1 is used.
As shown in Table 14, each of Examples 78 to 154 uses the same fluorescent material as that of Examples 1 to 77 as the first fluorescent material, and the second fluorescent material is further added to the first fluorescent material. The light emitting device is configured using Y ₃ Al ₅ O ₁₂ : Ce (YAG: Ce).
In addition, the second fluorescent material is a raw material oxide Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ and a flux such as fluoride are dry-mixed and packed in a crucible. The baked product obtained by calcination for ˜7 hours is ball milled, washed, separated and dried, and finally passed through a sieve.

  The second fluorescent material is a coprecipitated oxide obtained by coprecipitation with oxalic acid as a raw material and co-precipitating a solution obtained by dissolving rare earth elements of Y, Gd, and Ce in acid at a stoichiometric ratio. It is also possible to obtain a mixed raw material by mixing it with aluminum oxide, mix barium fluoride as a flux with this and pack it in a crucible, and obtain it by the same method as described above.

In Examples 78 to 154, the first fluorescent material produced in the same manner as in Examples 1 to 77, the second fluorescent material produced as described above, and a filler or diffusing agent made of SiO ₂ Is contained in a slurry composed of 90 wt% of nitrocellulose and 10 wt% of γ-alumina, applied to the back surface of the transparent window portion of the lid, and heated and cured at 220 ° C. for 30 minutes to constitute a color conversion member.

And after fully removing the water | moisture content in the recessed part of a package, the said recessed part is sealed with the Kovar lid which has a glass window part in the center part, and a light-emitting device is produced by seam welding.
The light-emitting device of Example 78 manufactured as described above has an emission spectrum as shown in FIG. 9, and the chromaticity coordinates are (x, y) = (0.360, 0) as shown in Table 14. .370) white light emission, and the light emission luminance when operated at 20 mA is 24 (lm / W).
Table 14 shows the characteristics (the chromaticity coordinates and the light emission luminance during operation at 20 mA) of Examples 78 to 154.

Table 14

Here, Example 107 was produced in the same manner as Example 30 except that a color conversion member was formed in the same manner as Example 30, and Example 108 was produced in the same manner as Example 31 except that a color conversion member was formed. did.
In Examples 1 to 154 above, only the chromaticity at the time of 365 nm excitation was shown. However, in Examples 1 to 154, the chromaticity at the time of 400 nm excitation was almost the same as the chromaticity at the time of 365 nm excitation, respectively. The value is shown.
As described in the above embodiments, according to the present invention, it is possible to provide a light emitting device that has good color rendering properties and can suppress a change in chromaticity.
Further, according to the present invention, when the fluorescent material is excited by light on the short wavelength side of visible light from the ultraviolet region, it can be adjusted to a desired color by the composition of the fluorescent material.

The light-emitting device according to the present invention is superior to the conventional one as a light source including illumination, taking advantage of the semiconductor light-emitting element.
Therefore, according to this invention, the outstanding light-emitting device which can be used for a signal lamp, illumination, a display, an indicator, various light sources, etc. can be provided.

FIG. 1 is a graph showing an example of an emission spectrum emitted from the light-emitting device according to Embodiment 1 of the present invention. 1 is a schematic plan view of a light emitting device (surface mounted light emitting device) according to a first embodiment of the present invention. It is typical sectional drawing of the light-emitting device of Embodiment 1 which concerns on this invention. It is a CIE chromaticity diagram showing the chromaticity of the light emitting devices of Examples 1, 9, and 17 according to the present invention. It is a graph which shows the emission spectrum by 365 nm excitation of the fluorescent substance used for Example 1 (broken line) and Example 9 (solid line). It is a graph which shows the excitation spectrum with respect to 450 nm emission of the fluorescent material used in Example 1 (broken line) and Example 9 (solid line). It is a graph which shows the excitation spectrum with respect to 590 nm light emission of the fluorescent material used in Example 1 (broken line) and Example 9 (solid line). It is the graph which showed the example of the emission spectrum of the semiconductor light emitting element used for the light emitting device of Embodiment 1 which concerns on this invention. It is a graph which shows typically the change of the emission spectrum of a fluorescent substance when the wavelength of a semiconductor light emitting element changes. It is a graph which shows an example of the emission spectrum discharge | released from the light-emitting device of Embodiment 2 which concerns on this invention. It is typical sectional drawing of the light-emitting device of the modification concerning this invention. It is FIG. (1) which shows a part of manufacturing process of the semiconductor light-emitting device used for Example 1 which concerns on this invention. FIG. 6B is a diagram (part 2) illustrating a part of the manufacturing process of the semiconductor light-emitting element of Example 1; FIG. 6 is a view (No. 3) showing a part of the manufacturing process of the semiconductor light-emitting element of Example 1; FIG. 14 is a view (No. 4) illustrating a part of the manufacturing process of the semiconductor light-emitting element of Example 1; FIG. 10 is a view (No. 5) showing a part of the manufacturing process of the semiconductor light-emitting element of Example 1; It is a top view of the semiconductor light-emitting device used for Example 1 which concerns on this invention. It is a top view which shows the electrode structure of the semiconductor light-emitting device of Embodiment 1 which concerns on this invention. FIG. 14 is a plan view showing an electrode configuration different from that in FIG. 13 in the semiconductor light emitting device of the first embodiment. FIG. 3 is a plan view showing a more preferable electrode configuration in the semiconductor light emitting device of the first embodiment. FIG. 16 is a plan view showing an electrode configuration of a modified example of FIG. 15 in the semiconductor light emitting device of the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 LED chip, 2 lead electrode, 3 through-hole, 4 Ag wire, 5 package, 6 Kovar lid, 7 glass window part, 8 fluorescent substance, 80 color conversion member.

Claims (18)

A light emitting element;
A first fluorescent material having an emission peak wavelength of 575 nm to 630 nm;
Unlike the first fluorescent material, a second fluorescent material that emits light from blue to red,
A white light emitting device comprising:   The white light emitting device according to claim 1, wherein the white light emitted by the white light emitting device does not include a visible light component emitted by the light emitting element.   The white light emitting device according to claim 1, wherein the light emitting element emits light between 340 nm and 440 nm.   4. The white light emitting device according to claim 1, wherein the light emitting element includes an InGaN active layer. 5.   5. The white light emitting device according to claim 1, wherein the first fluorescent material further has an emission peak wavelength of 380 nm to 485 nm.   The white light emitting device according to claim 1, wherein the first fluorescent material contains Eu and Mn.   The said 1st fluorescent substance contains at least 1 sort (s) selected from Mg, Ca, Ba, Sr, and Zn, The at least any one of Claim 1 thru | or 6 characterized by the above-mentioned. White light emitting device. Formula (M1 _1-ab Eu _a L1 _b ) ₁₀ (PO ₄ ) ₆ Q ₂
(However, M1 is at least one selected from Mg, Ca, Ba, Sr, and Zn, L1 is at least one selected from Mn, Fe, Cr, and Sn, and Q is selected from F, Cl, Br, and I. A fluorescent material having a composition represented by 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5),
The fluorescent material is excited by light having an emission spectrum from an ultraviolet region of 340 nm to 440 nm to a short wavelength region of visible light.   9. The fluorescent material according to claim 8, wherein a is 0.0001 ≦ a ≦ 0.2.   10. The fluorescent material according to claim 8, wherein b is 0.0001 ≦ b ≦ 0.3.   11. The fluorescent substance according to claim 8, wherein (1-a−b) satisfies 0.94 ≦ (1-a−b) ≦ 1. The fluorescent substance is a fluorescent substance according to at least any one of claims 8 to 11, characterized in that raw materials M1HPO ₄ and / or NH 4 _Q are used.   9. The fluorescent material according to claim 8, wherein Q is Cl and is partially replaced by F. A light-emitting device comprising a light-emitting element and a fluorescent material excited by light emitted from the light-emitting element,
The light emitting element has an emission spectrum from an ultraviolet region of 340 nm to 440 nm to a short wavelength region of visible light,
The light emitting device, wherein the fluorescent material is the fluorescent material according to at least one of claims 8 to 13.   15. The light emitting device further includes an oxide fluorescent material having at least one selected from Mg, Ca, Ba, Sr, and Zn, Al, and Eu. Light emitting device. The light emitting device further includes:
(1) A fluorescent substance represented by (M1 _1-ab Eu _a L1 _b ) ₁₀ (PO ₄ ) ₆ Q ₂ (where M1 is at least one selected from Mg, Ca, Ba, Sr, Zn) L1 has at least one selected from Mn, Fe, Cr, and Sn, and Q has at least one selected from the halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0 .5, 0.0001 ≦ b ≦ 0.5).
(2) A fluorescent material represented by (M1 _1-a Eu _a ) ₁₀ (PO ₄ ) ₆ Q ₂ (where M1 is at least one selected from Mg, Ca, Ba, Sr, Zn, and Q is And at least one selected from the halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5)
_{(3) (M1 1-a} -b Eu a Mn b) 10 (PO 4) 6 Q 2 with a fluorescent material represented (provided that at least one M1 is to Mg, Ca, Ba, Sr, are selected from Zn And Q has at least one selected from the halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5 and 0.0001 ≦ b ≦ 0.5.
_{(4) (M2 1-a} -c Eu a Ba c) 10 fluorescent substance represented by _{(PO 4)} 6 _{Q 2 (although,} M2 is at least one selected from Mg, Ca, Sr, Zn, Q has at least one selected from the halogen elements F, Cl, Br, and I. 0.0001 ≦ a ≦ 0.5 and 0.10 ≦ c ≦ 0.98).
(5) Fluorescent substance represented by M1 _1-a Eu _a Al ₂ O ₄ (where M1 has at least one selected from Mg, Ca, Ba, Sr, Zn. 0.0001 ≦ a ≦ 0 .5)),
_{(6) M1 1-a-} b Eu a Mn b Al 2 O 4 with a fluorescent material represented (although, M1 has at least one member selected Mg, Ca, Ba, Sr, from Zn .0.0001 ≦ a ≦ 0.5, 0.0001 ≦ b ≦ 0.5)
(7) Fluorescent substance represented by M3 _1-ac Eu _a Ca _c Al ₂ O ₄ (however, M3 has at least one selected from Mg, Ba, Sr, Zn. 0.0001 ≦ a ≦ 0.5 and 0.10 ≦ c ≦ 0.98).
(8) A fluorescent material represented by M4 _1-a Eu _a MgAl ₁₀ O ₁₇ (however, M4 has at least one selected from Ca, Ba, Sr and Zn. 0.0001 ≦ a ≦ 0.5 ),
(9) M4 _1-a Eu _a Mg _1-b Mn _b Al ₁₀ O ₁₇ fluorescent material (however, M4 has at least one selected from Ca, Ba, Sr, Zn) ≦ a ≦ 0.5, 0.0001 ≦ b ≦ 0.5)
(10) A fluorescent material represented by (M1 _1-a Eu _a ) ₄ Al ₁₄ O ₂₅ (where M1 has at least one selected from Mg, Ca, Ba, Sr, and Zn. 0.0001 ≦ a ≦ 0.5)
(11) A fluorescent material represented by ZnS: Cu,
(12) A fluorescent material represented by (Zn, Cd) S: Cu, Mn,
(13) A fluorescent material represented by Re ₂ O ₂ S: Eu (where Re has at least one selected from Sc, Y, La, Gd, and Lu),
The light emitting device according to claim 14, comprising at least one fluorescent material selected from the group consisting of: Fluorescent substance of the _{(M1 1-a-b Eu} a L1 b) 10 (PO 4) 6 Q 2 has at least two peaks, a different fluorescent materials that supplement the light between the two peaks The light-emitting device according to claim 14, comprising: The light emitting device according to claim 14, wherein the light emitting device further includes an aluminum oxide phosphor containing Y or Tb.

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