JP2005200584A - Fluorescent substance, light emitting system, iluminating system and image-displaying system using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent substance that gives high color rendering properties and develops deep red or white color and provide a light emitting system that is produced by using the fluorescent substance and can strongly emit visible light. <P>SOLUTION: The fluorescent substance includes the crystal phase having the chemical composition represented by formula [1] (wherein M<SP>1</SP>is a monovalent element or a divalent elements except Eu, Mn and Mg wherein the divalent elements occupies ≥80 mol%, the total of Ba, Ca and Sr is ≥40 mol% and the molar ratio of Ca to the total of Ba+Ca is <0.2; M<SP>2</SP>is a tetravalent element group including Si and Ge in an amount of ≥90 mol% in total; Z is a monovalent element, a divalent element, H or N; a, b, c, d, e, and f are each 0.0003≤a≤0.01, 0<b<0.075, 0<c/(c+d)≤0.8, 1.8≤(a+b+c+d)≤2.2, 0≤f/(e+f)≤0.035, 3.6≤(e+f)≤4.4). The light emitting system is prepared by combining the fluorescent substance with a light source for radiating the light of 350 to 430 nm wavelength. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a phosphor in which a host compound that absorbs light in the ultraviolet light or visible light region and emits visible light having a long wavelength contains an activator, and uses the phosphor as a second light emitter, and ultraviolet light is generated by a power source. The present invention relates to a light-emitting device capable of generating high-intensity light emission regardless of the use environment by combining a first light-emitting body that emits light in the visible light region and a second light-emitting body.

Conventionally, many phosphors that emit red light by ultraviolet light are known, and phosphors that emit white light are also known. The red phosphor is mixed with other phosphors in the emission color and used as white for illumination. Among these, the phosphor that is easy to manufacture and is stable is an oxide containing almost no S and halogen. The oxide containing almost no S and halogen is an oxide in which the content of S and halogen elements in the crystal is below the impurity level, that is, 2 mol% or less as a guide. This is because an oxide containing S as a crystal constituent element, such as La ₂ O ₂ S: Eu, is not stable when irradiated with ultraviolet light in the presence of water in the air or air, and Ca ₅ (PO ₄ ) ₃ (F, Cl): C, such as Sb, Mn
This is because an oxide containing a halogen such as l as a crystal constituent element is likely to be corroded during production and is not easy to produce. Among oxides containing almost no S and halogen, phosphors that emit red light are Y ₂ O ₃ : Eu, Y (P, V) O ₄ : Eu, (Sr, M
g) As a phosphor in which ₃ (PO ₄ ) ₂ : Sn emits white light, YVO ₄ : Dy is exemplified. (For example, it is described in the phosphor handbook (Edited by Phosphor Handbook, Ohm Co., 1987).) The red phosphor emits light in the ff transition process of Eu ³⁺ and gives a line spectrum. Even if a blue and green phosphor is combined with this, only white light with low color rendering can be obtained. Color rendering is one of the factors that cause problems when white light is generated by mixing different luminescent colors. The color appearance of an object illuminated by sunlight is illuminated by the light emitted by the phosphor. The color rendering property tends to increase as the half-value width of the phosphor emission spectrum increases. When white light is generated by mixing red, green, and blue phosphors, if the red emission peak width is small, there is a large valley between the green peak in the synthesized spectrum, that is, in the region of 550-590 nm. It is not possible to make it coincide with the sunlight spectrum having no valleys in the region, and the color rendering property is lowered. For this reason, it is difficult to obtain white light having a high color rendering property with a red phosphor such as Y ₂ O ₃ : Eu or Y (P, V) O ₄ : Eu that emits a line spectrum having a half width of less than 20 nm. is there.
A red phosphor such as (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn emits light by excitation of a conventional 254 nm mercury emission line, but it can hardly emit light due to a recently developed GaN-based semiconductor with a strong long wavelength light source. However, the excitation source is very limited and is not satisfactory. The white phosphor has a low color rendering property. This emits white light with a blue color near 480 nm and a yellow color near 570 nm, which are in a complementary color relationship. Since the red and green components are insufficient, the color rendering is low. As described above, conventional red and white phosphors containing almost no S and halogen have a problem that they cannot give good color rendering and vividness because the red emission peak is narrow or the wavelength is too short. Alternatively, there is a problem that the red component does not emit light with a light source near 400 nm.

In recent years, a light emitting device that emits white light in which a red or white phosphor containing almost no S and halogen is combined with a GaN-based semiconductor that emits strong near-ultraviolet light at a low voltage has a low power consumption and is long. have been proposed as a light emitting source of life image display device or a lighting device, as an example of the case where phosphor combined is red phosphor, Y ₂ O _3: While Eu may be mentioned, Y ₂
O _3: Eu and the blue, green phosphors, and the color rendering properties of white light obtained when a combination of a near-ultraviolet light emitting source, Y ₂ O _3: emission spectrum of Eu is for line spectrum, similar to the previously described Low for reasons and low emission intensity. As an example of the case where the phosphor to be combined is a white phosphor, Japanese Patent Application Laid-Open No. 2002-359404 discloses a method using a phosphate and / or borate phosphor. However, according to this method, a sufficiently wide emission spectrum reaching the blue to red region cannot be obtained, the color rendering property is low, and a bright emission color cannot be obtained. Other red phosphors include CaSiO ₃ : Pb, Mn, (Zn, Cd) S: Cu, Al, and (Zn, Cd
) S: Ag, etc., but because toxic Cd and Pb are used, it becomes a factor that deteriorates the living environment, and the development of phosphors that do not use such elements has been desired. .

Furthermore, when used in a phosphor combined with a GaN-based semiconductor, the temperature in the vicinity of the phosphor becomes higher than room temperature due to heat generation of the semiconductor, so that the luminance at a temperature higher than room temperature is required to be sufficiently high.
As described above, conventional lighting devices and image display devices incorporating red and white phosphors, which are easy to manufacture and stable, have insufficient deep red component peaks, so that bright and highly color-rendering light is emitted. It was not obtained and was not satisfactory.
JP 2002-359404 A

  The present invention provides high color rendering properties and vividness in view of the above-described prior art, in other words, a bright and deep red component in the 615-645 nm region and a wide emission peak. Red or white phosphors, especially phosphors that emit red or white light with high color rendering properties and intensity in combination with near-ultraviolet light sources, have good temperature characteristics, are easy to manufacture, and are stable. The purpose is to provide a body.

As a result of intensive studies to solve the above problems, the present inventor has given a red emission peak having a large half-value width and a peak top of 615 to 645 nm, or an emergency that spans the blue region as well as the red peak. A phosphor that gives an emission spectrum having a large width and emits strong red or white light when irradiated with light of 350 to 430 nm, specifically, low concentrations of Eu and Mn The present inventors found an M ₂ SiO ₄ type silicate containing Ba and Mg with no Ca or less than a small amount of Ca. In particular, the phosphor of the present invention is strongly emitted by any light source in an enormous wavelength region extending from around 250 nm to around 400 nm, is bright, and is based on a deep red color. And has a characteristic of good temperature characteristics.

  That is, the first aspect of the present invention is a phosphor having a crystal phase having a chemical composition represented by the following general formula [1], the first illuminant that emits light of 350 to 430 nm, and the first In a light emitting device having a second light emitter that generates visible light upon irradiation of light from the light emitter, the second light emitter has a crystal phase having a chemical composition represented by the following general formula [1] A light emitting device characterized in that is a second gist thereof.

(However, M ¹ represents a monovalent element, a divalent element other than Eu, Mn, and Mg, at least one element selected from the group of trivalent elements, and pentavalent elements. is not less proportion of more than 80 mol%, Ba, Ca, the percentage of total occupied Sr not less than 40 mol%, the proportion of Ca to the sum of Ba and Ca (mole ratio) is less than 0.2 .M ² Si and G
A tetravalent element group containing 90 mol% or more of e in total is represented, and Z is at least one element selected from the group consisting of a −1 valent element, a −2 valent element, H, and N. a is 0.0003 ≦ a ≦ 0.01, b is 0 <b <0.075, c and d are 0 <c / (c + d) ≦ 0.8, and a, b, c and d are 1.8 ≦ (A + b + c + d) ≦ 2.2, e and f are numbers satisfying 0 ≦ f / (e + f) ≦ 0.035 and 3.6 ≦ (e + f) ≦ 4.4. )

  According to the present invention, a deep red color or a bright white phosphor having a high color rendering property and a high color rendering property, and a light emission that emits strong visible light even when exceeding room temperature. An apparatus can be provided.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.
The present invention is a phosphor having a crystal phase having a chemical composition of the following general formula [1], a phosphor having a crystal phase having a chemical composition of the following general formula [1], and a phosphor having a crystal phase of 350 to 430 nm. And a light emitting device for irradiating light.

M ¹ in the formula [1] is a monovalent element, a divalent element excluding Eu, Mn, and Mg, a trivalent element,
It represents at least one element selected from the group of pentavalent elements, the proportion of divalent elements is 80 mol% or more, the proportion of the total of Ba, Ca, and Sr is 40 mol% or more, and Ba and It satisfies the condition that the ratio (molar ratio) of Ca to the total of Ca is less than 0.2. When elements other than Ba, Ca, and Sr are specifically described, examples of monovalent elements include Li, Na, K, Rb, and Cs. Examples of divalent elements include V, Cr, Fe, and Co. , Ni, Cu, Zn, Mo, Ru, Pd, Ag, Cd, Sn, Sm, Tm, Yb, W, Re, Os, Ir, Pt, Hg, Pb, and the like. B, Al, Ga, In, and the like, and rare earth elements such as Y, Sc, and the like. Examples of the pentavalent element include, but are not limited to, P, Sb, Bi, and the like. Among the divalent elements, V, Zn, Mo, Sn, Sm, Tm, Yb, W, and Pb are among others.

A total of 20 mol% of monovalent, trivalent, and pentavalent elements is used to aid crystallization of silicate by diffusion in the solid during firing of divalent elements and activators Eu ²⁺ and Mn ²⁺ in M ^1. May be introduced within. In terms of a deep red component or the like, the ratio (molar ratio) of Ca to the total of Ba and Ca is preferably less than 0.1, and more preferably 0. The ratio (molar ratio) of Ca to the total of Ba and Ca must be greater than 0 in terms of obtaining a visible light spectrum with a very high color rendering property in which the blue peak, the green peak, and the red peak are aligned at a sufficient ratio. Is preferable, and 0.1 or more is more preferable.

From the viewpoint of red or white emission intensity, the proportion of the total of Ba, Ca, Sr is preferably 80 mol% or more, more preferably the proportion of the total of Ba, Ca is 80 mol% or more, More preferably, the ratio of the total of Ba, Ca and Sr is 100 mol%.
M ² in the formula [1] represents a tetravalent element group containing 90 mol% or more of Si and Ge in total, but M ² contains 80 mol% or more of Si in terms of red or white emission intensity. It is more preferable that M ² is made of Si. Examples of tetravalent elements other than Si and Ge include Zn, Ti, Hf, and the like, and these may be included within a range that does not impair the performance in terms of red or white emission intensity.

  Z in the formula [1] is at least one element selected from the group consisting of a −1 valent element, a −2 valent element, H, and N. For example, S, which is a −2 valent element similar to oxygen, In addition to Se and Te, it may be −1 valent F, Cl, Br, I, etc., OH group may be contained, and oxygen group is partially changed to ON group or N group. Also good. Z may be contained to such an extent that the fluorescent performance is not affected, that is, the impurity level to the total element ratio is about 2 mol% or less. This corresponds to a molar ratio of Z to (Z + oxygen atom) of 0.035 or less. Therefore, the range of f / (e + f), which is the molar ratio of Z to (Z + oxygen atom), is 0 ≦ f / (e + f) ≦ 0.035. From the viewpoint of phosphor performance, f / (e + f) ≦ 0.01 is preferable, and f / (e + f) = 0 is preferable in normal use.

Regarding the Eu molar ratio a in the formula [1], a is a number satisfying 0.0003 ≦ a ≦ 0.01. When a GaN-based semiconductor is used as the first light emitting source, the surface temperature of the semiconductor chip exceeds 100 ° C. during operation, but in order to efficiently emit the phosphor, when the phosphor is installed near the chip surface, The temperature at the time of operation of the phosphor becomes close to 100 ° C. Therefore, since the actual use temperature of the phosphor is close to 100 ° C., it is desirable to use a phosphor whose luminance does not decrease much even when the temperature rises to 100 ° C. When the molar ratio a of the luminescent center ion Eu ²⁺ is large, Since the luminance is reduced at the above temperature, by setting the molar ratio a to 0.01 or less, the luminance does not decrease even when the temperature is raised to around 100 ° C., and it is possible to prevent the temperature characteristics from being deteriorated. If the molar ratio “a” of the luminescent center ion Eu ²⁺ is too small, the emission intensity tends to decrease, and the lower limit is more preferably a ≧ 0.001, and more preferably a ≧ 0.002.

The Mn molar ratio b in the formula [1] is a factor that determines whether to emit red light or white light. When b is 0, a red peak is not obtained and only a blue or blue-green peak is obtained. However, when b takes a small positive value, a red peak appears in the blue and green peaks, and the whole emits white light, and when b takes a larger positive value, the blue and green peaks become very small and red. The peak is the main. The range of b is 0 <b <0.075 as a red phosphor or a white phosphor. Energy Eu ²⁺ phosphor has excited by the irradiation of the excitation light source is moved to Mn ^2+, it believed that Mn ²⁺ is red-emitting, energy mainly by the composition of M ¹ and M ² Since the degree of movement is slightly different, the boundary value of b for switching from the red phosphor to the white light phosphor is slightly different depending on the composition of M ¹ and M ² . Therefore, the good range of b of red light emission and white light emission cannot be strictly distinguished, but 0.002 ≦ b <0.075 is more preferable from the viewpoint of the intensity of light emission colors including red and white, and 0 0.005 ≦ b <0.075 is more preferable. In the present invention, “white” is to be interpreted in a broad sense, and means that there are two or more maximum values in the emission spectrum, each of which is a broadband emission peak.

Mg in the formula [1] is substituted with M ¹ which is mainly a divalent element, and c / (c + d) which is a ratio of the number of moles of Mg to the total number of moles of Mg and M ¹ is 0 <c / Although (c + d) ≦ 0.8, 0 <c / (c + d) ≦ 0.7 is preferable from the viewpoint of red or white emission intensity.
In the crystal phase Eu _a Mn _b Mg _c M ¹ _d M ² O _e Z _f of the general formula [1], Eu ²⁺ , Mn ²⁺ , and Mg ²⁺ are replaced with M ¹ mainly composed of a divalent element. M ² is mainly occupied by Si and Ge, the anion is mainly oxygen, and the basic composition is that of M ¹ , M ² , and the total molar ratio of oxygen atoms of ² , ¹ , 4 respectively. However, even if some cation deficiency or anion deficiency occurs, the fluorescence performance for this purpose is not greatly affected. Therefore, when the total molar ratio of M ² mainly occupied by Si and Ge is fixed to 1 in the chemical formula, The molar ratio (a + b + c + d) of M ¹ + Eu + Mn + Mg is 1.8 ≦ (
a + b + c + d) ≦ 2.2, and (a + b + c + d) = 2 is particularly preferable. Further, the total molar ratio of the sites on the anion side (e + f) is usually in the range of 3.6 ≦ (e + f) ≦ 4.4, and among them, it is preferable that e = 4 and f = 0. .

The phosphor used in the present invention includes an M ¹ source, an M ² source, an Mg source, and Eu and Mn element source compounds as shown in the general formula [1] described below (A ) Or (B) can be produced by heat-treating the mixture prepared by the mixing method.
(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., pulverization using mortar and pestle, etc., mixer such as ribbon blender, V-type blender and Henschel mixer, or mortar and pestle Dry mixing method combined with mixing.
(B) Using a pulverizer or a mortar and pestle, etc., add water etc. and mix in a slurry or solution state with a pulverizer, mortar and pestle, or evaporating dish and stirrer, spray drying, heating Wet mixing method that is dried by drying or natural drying.

  Among these mixing methods, in particular, in the element source compound of the activator element, it is preferable to use a liquid medium because it is necessary to uniformly mix and disperse a small amount of the compound, and other elements The latter wet method is preferable from the viewpoint of obtaining uniform mixing throughout the source compound, and the heat treatment method is usually 750 to 1500 ° C. in a heat-resistant container such as a crucible or tray made of alumina or quartz. The heating is preferably performed at a temperature of 900 to 1400 ° C. for 10 minutes to 24 hours in a single or mixed atmosphere of a gas such as air, oxygen, carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon. In addition, after heat processing, washing | cleaning, drying, a classification process, etc. are made | formed as needed.

As the heating atmosphere, an atmosphere necessary for obtaining an ion state (valence) in which the activating element contributes to light emission is selected. In the case of divalent Eu and Mn in the present invention, a neutral or reducing atmosphere such as carbon monoxide, nitrogen, hydrogen, and argon is preferable, but it can be selected even under an oxidizing atmosphere such as air and oxygen. It is.
Here, as the element source compounds of the M ¹ source, M ² source, Mg source, and activator element, M ¹ ,
M ² , Mg, and each of the oxides, hydroxides, carbonates, nitrates, sulfates, oxalates of the activating elements,
Carboxylic acid salts, halides and the like can be mentioned, and these are selected in consideration of reactivity to the composite oxide and non-generation of NOx, SOx, etc. during firing.

The Ba listed as M ^1, Ca, the Sr, if specific examples thereof M ¹ source compound, as a Ba source _{compound, BaO, Ba (OH) 2} · 8H 2 O, BaCO 3
, Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) ₂ .2H ₂ O, Ba (OCOCH ₃ ) ₂ , B
aCl _{2 and the} like, and Ca source compounds include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (
NO ₃ ) ₂ · 4H ₂ O, CaSO ₄ · 2H ₂ O, Ca (OCO) ₂ · H ₂ O, Ca (OCOCH ₃ ) ₂ · H ₂ O, CaCl _2, etc. SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (OCO) ₂ .H ₂ O, Sr (OCO
CH ₃ ) ₂ · 0.5H ₂ O, SrCl _{2 and the} like.

Specific examples of the M ² source compounds for the Si and Ge mentioned as M ² include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _4, etc. Examples of the Ge source compound include GeO ₂ , Ge (OH) ₄ , Ge (OCOCH ₃ ) ₄ , and GeCl ₄ .
For Mg, specific examples of Mg source compounds include MgO, Mg (OH) ₂ , MgC
O ₃ , Mg (OH) ₂ .3MgCO ₃ .3H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, MgSO ₄ , Mg (OCO) ₂ .2H ₂ O, Mg (OCOCH ₃ ) ₂ .4H ₂ O , MgCl _{2 and the} like.

Further, with respect to Eu and Mn mentioned as the activation elements, specific examples of the element source compounds include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (OCO) ₆ , EuCl ₂ and EuCl. _Three
Eu (NO ₃ ) ₃ .6H ₂ O, Mn (NO ₃ ) ₂ .6H ₂ O, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄
, MnO, Mn (OH) ₂ , MnCO ₃ , Mn (OCOCH ₃ ) ₂ .2H ₂ O, Mn (OCO
CH ₃ ) ₃ · nH ₂ O, MnCl ₂ · 4H ₂ O and the like.

In the present invention, the first light emitter that irradiates the phosphor with light generates light having a wavelength of 350 to 430 nm. Preferably, a light emitter that generates light having a peak wavelength in the wavelength range of 350 to 430 nm is used. Specific examples of the first light emitter include a light emitting diode (LED) or a laser diode (LD). A laser diode is more preferable because it consumes less power. Of these, GaN LEDs and LDs using GaN compound semiconductors are preferred. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, the GaN system usually has a light emission intensity 100 times or more that of the SiC system. GaN-based LEDs and LDs preferably have an Al _x Ga _Y N light emitting layer, a GaN light emitting layer, or an In _x Ga _Y N light emitting layer. Among the GaN-based LEDs, those having an InXGaYN light-emitting layer are particularly preferred because the emission intensity is very strong, and GaN-based LDs have a multiple quantum well structure of In _x Ga _y N layer and GaN layer. Is particularly preferable because of its very high emission intensity. In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics. A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic constituent elements. The light-emitting layer is made of n-type and p-type Al _x Ga _y N layers, GaN layers, or In _x. Those having a heterostructure sandwiched between Ga _Y N layers and the like have high luminous efficiency, and those having a heterostructure having a quantum well structure have higher luminous efficiency and are more preferable.

  In the present invention, it is particularly preferable to use a surface-emitting type illuminant, particularly a surface-emitting GaN-based laser diode, as the first illuminant because the luminous efficiency of the entire light-emitting device is increased. A surface-emitting type illuminant is an illuminant that emits strong light in the surface direction of a film. In a surface-emitting GaN-based laser diode, the crystal growth of a light-emitting layer or the like is controlled, and a reflective layer or the like is successfully performed. By devising, the light emission in the surface direction can be made stronger than the edge direction of the light emitting layer. When the surface emitting type is used, the light emission cross-sectional area per unit light emission amount can be increased compared to the type that emits light from the edge of the light emitting layer. As a result, the phosphor of the second light emitter is irradiated with the light. Since the irradiation area can be made very large with the same amount of light and the irradiation efficiency can be improved, stronger light emission can be obtained from the phosphor that is the second light emitter.

When a surface-emitting type is used as the first light emitter, the second light emitter is preferably a film. As a result, the cross-sectional area of the light from the surface-emitting type light emitter is sufficiently large. Therefore, when the second light emitter is formed into a film in the direction of the cross section, the irradiation cross-section area of the phosphor from the first light emitter is irradiated. Becomes larger per unit amount of phosphor, so that the intensity of light emitted from the phosphor can be further increased.
Further, when a surface-emitting type is used as the first light emitter and a film-like one is used as the second light emitter, the second light emitter directly in the form of a film on the light-emitting surface of the first light emitter. It is preferable to have a shape in which is contacted. Contact here refers to creating a state in which the first light emitter and the second light emitter are in perfect contact with each other without air or gas. As a result, it is possible to avoid a light amount loss in which light from the first light emitter is reflected by the film surface of the second light emitter and oozes out, so that the light emission efficiency of the entire apparatus can be improved.

FIG. 1 is a schematic perspective view showing the positional relationship between the first light emitter and the second light emitter in an example of the light emitting device of the present invention. In FIG. 1, 1 is a film-like second light emitter having the phosphor, 2 is a surface-emitting GaN-based LD as the first light emitter, and 3 is a substrate. In order to create a state in which they are in contact with each other, the LD 2 and the second light emitter 1 may be formed separately and the surfaces may be brought into contact with each other by an adhesive or other means, or the light emitting surface of the LD 2 A second light-emitting body may be formed (molded) on the top. As a result, the LD 2 and the second light emitter 1 can be brought into contact with each other.

  The light from the first illuminant and the light from the second illuminant are usually directed in all directions. However, when the phosphor powder of the second illuminant is dispersed in the resin, the light is out of the resin. A part of the light is reflected when exiting, so the direction of the light can be adjusted to some extent. Accordingly, since light can be guided to a certain degree in an efficient direction, it is preferable to use a phosphor in which the phosphor powder is dispersed in a resin as the second luminous body. Further, when the phosphor is dispersed in the resin, the total irradiation area of the light from the first light emitter to the second light emitter is increased, so that the light emission intensity from the second light emitter can be increased. It also has the advantage of being able to. Examples of the resin that can be used in this case include various resins such as silicon resin, epoxy resin, polyvinyl resin, polyethylene resin, polypropylene resin, and polyester resin, which are preferable in terms of good dispersibility of the phosphor powder. Is a silicon resin or an epoxy resin. When the powder of the second luminous body is dispersed in the resin, the weight ratio of the powder of the second luminous body to the whole of the resin is usually 10 to 95%, preferably 20 to 90%, more preferably. Is 30-80%. If the phosphor is too much, the luminous efficiency may be reduced due to aggregation of the powder, and if it is too little, the luminous efficiency may be lowered due to light absorption or scattering by the resin.

  The light-emitting device of the present invention includes the phosphor as a wavelength conversion material and a light-emitting element that generates 350-430 nm light, and the phosphor absorbs 350-430 nm light emitted from the light-emitting element. In addition, the phosphor having a good color rendering property and capable of generating high-intensity visible light regardless of the use environment, and the phosphor having the crystal phase of the present invention constituting the light-emitting device has a wavelength of 350 to 430 nm. By emitting light from the first light-emitting body that generates the light, light is emitted in a wavelength region representing red or white. The light-emitting device of the present invention is suitable for a light source such as a backlight source, a light source such as a traffic light, an image display device such as a color liquid crystal display, and a lighting device such as a surface light source.

  The light emitting device of the present invention will be described with reference to the drawings. FIG. 2 is a schematic cross-sectional view showing an embodiment of a light emitting device having a first light emitter (350-430 nm light emitter) and a second light emitter. 4 is a light emitting device, 5 is a mount lead, 6 is an inner lead, 7 is a first light emitter (350-430 nm light emitter), 8 is a phosphor-containing resin portion as a second light emitter, 9 Is a conductive wire, and 10 is a mold member.

  As shown in FIG. 2, the light emitting device as an example of the present invention has a general bullet shape, and a first light emitter made of a GaN-based light emitting diode or the like is disposed in the upper cup of the mount lead 5. (350-430 nm illuminant) 7 is a phosphor formed as a second illuminant by mixing and dispersing the phosphor in a binder such as silicon resin, epoxy resin or acrylic resin, and pouring it into the cup. It is fixed by being covered with the body-containing resin portion 8. On the other hand, the first light emitter 7 and the mount lead 5, and the first light emitter 7 and the inner lead 6 are each electrically connected by a conductive wire 9, and these are entirely covered with a mold member 10 made of epoxy resin or the like, Protected.

  Further, as shown in FIG. 3, the surface emitting illumination device 11 incorporating the light emitting element 1 has a large number of light emission on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. The device 13 is arranged with a power supply and a circuit (not shown) for driving the light emitting device 13 provided outside thereof, and a milky white acrylic plate or the like is provided at a position corresponding to the lid portion of the holding case 12. The diffusion plate 14 is fixed for uniform light emission.

Then, by driving the surface emitting illumination device 11 and applying a voltage to the first light emitter of the light emitting element 13, light of 350 to 430 nm is emitted, and a part of the light emission is used as the second light emitter. The phosphor in the phosphor-containing resin part absorbs and emits visible light, while light emission with high color rendering properties is obtained by mixing with blue light or the like that is not absorbed by the phosphor. 14, is emitted upward in the drawing, and illumination light with uniform brightness is obtained within the surface of the diffusion plate 14 of the holding case 12.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

Ba (NO ₃ ) ₂ aqueous solution, Ca (NO ₃ ) ₂ .4H ₂ O aqueous solution, Mg (NO ₃ ) ₂ .6H ₂ O aqueous solution, Eu (NO ₃ ) ₃ .6H ₂ O aqueous solution, Mn ( NO ₃ ) ₂ · 6H ₂ O aqueous solution and colloidal silica (SiO ₂ ) suspension (Ba (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ · 4H ₂ O, Mg (NO ₃ ) ₂ · 6H ₂ O, Eu (NO ₃ ) ₃ · 6H ₂ O, Mn (NO ₃ ) ₂ · 6H ₂ O, S
An iO ₂ molar ratio of 1.218: 0.23: 0.512: 0.01: 0.03: 1) was mixed in a platinum vessel, dried, and then dried at 1050 ° C. under a nitrogen gas flow containing 4% hydrogen. The phosphor Ba _1.218 Ca _0.23 Mg _0.512 Eu _0.01 Mn _0.03 SiO ₄ (phosphor used for the second luminous body) was manufactured by heating for 2 hours. The emission spectrum was measured when this phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows the wavelength of the peak of the red component, the intensity when the intensity of the peak of the red component of Comparative Example 2 described later is 100 (hereinafter referred to as relative intensity), the half-value width, and room temperature (23 ° C) The luminance ratio at 80 ° C. and 100 ° C. assuming the operating state when the phosphor and the GaN-based light emitting diode are combined and the chromaticity coordinates when the luminance at 1 ° C. is 1 The x value, y value, and the half width of the peak group are shown. Since this phosphor has a sufficiently large intensity and half-width, it gives high color rendering properties and has a peak wavelength in the region of 615 to 645 nm, so that it can emit bright white light containing a bright deep red component. Understand. It can be seen that even when the temperature is around 100 ° C. generated when combined with a GaN-based semiconductor, the luminance is the same as that at room temperature.

The red component peak refers to a peak in a region of 590 nm or more in the emission spectrum. The half width of the peak group is a measure for knowing how widely the emission spectrum is distributed and how high the color rendering is, and as shown in FIG. 4, the intensity of the maximum peak in the emission spectrum. Is defined as the sum of the widths of the wavelength regions having an intensity of more than half.
(Comparative Example 1)
Ba (NO ₃ ) ₂ aqueous solution, Ca (NO ₃ ) ₂ · 4H ₂ O aqueous solution, Mg (NO ₃ ) ₂ · 6H ₂ O aqueous solution, Eu (NO ₃ ) ₃ · 6H ₂ O aqueous solution, and colloidal Silica (SiO ₂ ) suspensions (Ba (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ .4H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, Eu (NO ₃ ) ₃ .6H ₂ O, The phosphor Ba _1.187 Ca is the same as in Example 1 except that the molar ratio of SiO ₂ is 1.187: 0.396: 0.198: 0.2: 0.02: 1). _0.396 Mg _0.198 Eu _0.2 Mn _0.02 SiO ₄ was produced. The emission spectrum was measured when this phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows a combination of the phosphor and a GaN-based light-emitting diode when the red component peak wavelength, relative intensity, half-width, and luminance at room temperature (23 ° C.) are set to 1. The ratio of the luminance under 80 ° C. and 100 ° C., the x value, the y value of the chromaticity coordinates, and the half-value width of the peak group are shown assuming the operating state at the time. It can be seen that when the Eu molar ratio is increased from 0.01 to 0.2, the luminance at 80 ° C. or 100 ° C. decreases compared to that at room temperature.
(Comparative Example 2)
Ba (NO ₃ ) ₂ aqueous solution, Ca (NO ₃ ) ₂ .4H ₂ O aqueous solution, Mg (NO ₃ ) ₂ .6H ₂ O aqueous solution, Eu (NO ₃ ) ₃ .6H ₂ O aqueous solution, Mn ( NO ₃ ) ₂ · 6H ₂ O aqueous solution and colloidal silica (SiO ₂ ) suspension (Ba (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ · 4H ₂ O, Mg (NO ₃ ) ₂ · 6H ₂ O, Eu (NO ₃ ) ₃ · 6H ₂ O, Mn (NO ₃ ) ₂ · 6H ₂ O, S
Phosphor Ba _1.144 Ca in the same manner as in Example 1 except that the molar ratio of iO ₂ is 1.144: 0.216: 0.48: 0.01: 0.15: 1). _0.216 Mg _0.48 Eu _0.01 Mn _0.15 SiO ₄ was produced. The emission spectrum was measured when this phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows a combination of the phosphor and a GaN-based light-emitting diode when the red component peak wavelength, relative intensity, half-width, and luminance at room temperature (23 ° C.) are set to 1. The ratio of the luminance under 80 ° C. and 100 ° C., the x value, the y value of the chromaticity coordinates, and the half-value width of the peak group are shown assuming the operating state at the time. In Example 1, it is understood that when the Mn molar ratio is increased from 0.03 to 0.15, the red light emission intensity is greatly reduced.
(Comparative Example 3)
Ba (NO ₃ ) ₂ aqueous solution, Ca (NO ₃ ) ₂ · 4H ₂ O aqueous solution, Mg (NO ₃ ) ₂ · 6H ₂ O aqueous solution, Eu (NO ₃ ) ₃ · 6H ₂ O aqueous solution, and colloidal Silica (SiO ₂ ) suspensions (Ba (NO ₃ ) ₂ , Ca (NO ₃ ) ₂ .4H ₂ O, Mg (NO ₃ ) ₂ .6H ₂ O, Eu (NO ₃ ) ₃ .6H ₂ O, The phosphor Ba _1.2 Ca _0.2 Mg _0.4 E was used in the same manner as in Example 1 except that the molar ratio of SiO ₂ was 1.2: 0.2: 0.4: 0.2: 1).
u _0.2 SiO ₄ was produced. The emission spectrum was measured when this phosphor was excited at 400 nm, which is the dominant wavelength in the ultraviolet region of a GaN-based light emitting diode. Table 1 shows the x value and y value of the chromaticity coordinates, and the half width of the peak group. It can be seen that no peak of 590 nm or more is observed, and no red peak appears when Mn is not added.

The figure which shows an example of the light-emitting device which made the film-like fluorescent substance contact or shape | mold to the surface emitting type GaN-type diode. It is typical sectional drawing which shows one Example of the light-emitting device comprised from the fluorescent substance in this invention, and a 1st light-emitting body (350-430 nm light-emitting body). The typical sectional view showing an example of the surface emitting illumination device of the present invention. The figure showing the method of measuring the half value width of a peak group.

Explanation of symbols

1; second light emitter 2; surface-emitting GaN-based LD
3; Substrate 4; Light emitting device 5; Mount lead 6; Inner lead 7; First light emitter (light emitter of 350 to 430 nm)
8; Resin part containing phosphor in the present invention 9; Conductive wire 10; Mold member 11; Surface-emitting illumination device 12 incorporating a light-emitting element; Holding case 13; Light-emitting device 14;

Claims (7)

A phosphor having a crystal phase having a chemical composition represented by the following general formula [1].

(However, M ¹ represents a monovalent element, a divalent element other than Eu, Mn, and Mg, at least one element selected from the group of trivalent elements, and pentavalent elements. is not less proportion of more than 80 mol%, Ba, Ca, the percentage of total occupied Sr not less than 40 mol%, the proportion of Ca to the sum of Ba and Ca (mole ratio) is less than 0.2 .M ² Si and G
A tetravalent element group containing 90 mol% or more of e in total is represented, and Z is at least one element selected from the group consisting of a −1 valent element, a −2 valent element, H, and N. a is 0.0003 ≦ a ≦ 0.01, b is 0 <b <0.075, c and d are 0 <c / (c + d) ≦ 0.8, and a, b, c and d are 1.8 ≦ (A + b + c + d) ≦ 2.2, e and f are numbers satisfying 0 ≦ f / (e + f) ≦ 0.035 and 3.6 ≦ (e + f) ≦ 4.4. ) The phosphor according to claim 1, wherein a ratio of the total of Ba, Ca, and Sr in M ¹ is 80 mol% or more. The phosphor according to 1 or 2, wherein the proportion of Si in M ² is 80 mol% or more. In a light-emitting device including a first light-emitting body that generates light of 350 to 430 nm and a second light-emitting body that generates visible light when irradiated with light from the first light-emitting body, the second light-emitting body includes: A light emitting device comprising the phosphor according to any one of claims 1 to 3. The light emitting device according to claim 4, wherein the first light emitter is a laser diode or a light emitting diode. An illumination device comprising the light emitting device according to claim 4. An image display device comprising the light emitting device according to claim 4.

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