JP2006232949A - Method for treating phosphor particle, light emitting device, and phosphor particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for treating phosphor particles capable of enhancing not only dispersibility in a resin but also fluorescence characteristics. <P>SOLUTION: When the surface of a phosphor particle is coated with a metal oxide, the phosphor particle is brought into contact with a treatment solution containing a metal complex ion which comprises a metal composing the metal oxide as a central metal and fluorine as a ligand and water. A fluoride ion produced by the reaction of the metal complex ion with water can etch the surface of the phosphor particle to remove defective parts on the surface of the phosphor particle and disintegrate phosphor particles forming aggregates by necking. Subsequently, the surface of the phosphor particle can be coated with the metal oxide produced by the reaction of the metal complex ion with water on the surface of the phosphor particle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for treating phosphor particles in which the surface of phosphor particles is coated with a metal oxide, a light emitting device using phosphor particles coated with a metal oxide, and a phosphor particle coated with a metal oxide. Is.

  2. Description of the Related Art Conventionally, a color image display device, an electrical decoration, a signal lamp, a lighting device, and the like are configured by collecting and arranging light sources that emit light of various wavelengths. As the light source, a semiconductor light emitting element such as a light emitting diode (LED) or a semiconductor laser (LD) is used alone, or a combination of the light emitting element and a phosphor is used. When a phosphor is used in combination with a light-emitting element, a phosphor that is excited by light from the light-emitting element and emits fluorescence of various wavelengths is selected and used. Thus, in the light-emitting device formed by combining the phosphor with the light-emitting element, a so-called white LED that outputs white light can be formed by selecting the emission color of the phosphor. Etc. are expected to be used.

  When the phosphor is used in combination with the light emitting element as described above, the phosphor powder is generally mixed with the transparent resin and dispersed in the transparent resin. In this way, when the phosphor powder is dispersed in the resin, if the particle size of the phosphor particles is large, it will settle during curing of the resin due to its own weight. There was a problem.

  Therefore, it has been studied to improve dispersibility by dispersing phosphor particles prepared in fine particles having a particle size of 300 nm or less in a transparent resin. As a method for preparing such phosphor particles having a particle size of 300 nm or less, there are a coprecipitation method, an alkoxide method, and the like. In preparing the phosphor particles by these methods, in order to exhibit the performance of the phosphor. Sintering at a temperature of 1000 ° C. or higher may be necessary. When sintering is performed in this manner, necking of small particles occurs, phosphor particles aggregate to a particle size of 1 μm or more, dispersibility There was a problem that it was difficult to improve. In addition, as a result of necking, the particle size of the phosphor particles becomes non-uniform, and there is a problem that the high filling of the resin is limited. In addition, when the phosphor particles are prepared to have a particle size of 300 nm or less, there is a problem that a decrease in luminous efficiency due to surface defects becomes remarkable due to an increase in the surface area.

As a method for solving these problems, the phosphor particles prepared by the coprecipitation method or the alkoxide method as described above are sintered, and then the phosphor particles are etched to form a necking portion between small particles. A method for producing phosphor particles having a particle size of 300 nm or less has been studied. Furthermore, as a method of reducing defects on the surface of the phosphor particles, the surface of the phosphor particles is etched by SiO ₂ after etching the surface of the phosphor particles and removing a defective portion on the surface, and then using a metal alkoxide or the like. A method of coating with a metal oxide such as non-patent document 1 has been proposed.
Tetsuhiko Isobe, Kiyoshi Kurokawa, Keiji Fujimoto “Progress of Research and Development on IIB-VIB Group Nanocrystal Phosphors”, Applied Physics, Physics Society, 2003, Vol. 72, No. 12, p1516-1521

  However, when the metal oxide is coated on the surface of the phosphor particles using the metal alkoxide as described above, it is necessary to perform a process of forming a metal oxide film after the phosphor particles are removed by etching. When the phosphor particles are taken out, defects tend to occur again on the surface of the phosphor particles. Therefore, even if the surface of the phosphor particles is coated with a metal oxide film, the fluorescence characteristics tend to deteriorate. was there. Also, the metal oxide film tends to be unevenly formed on the surface of the phosphor particles, and the surface of the phosphor particles cannot be completely covered with the metal oxide, and defects are easily generated again on the uncoated surface. Similarly, there was a tendency that the fluorescence characteristics deteriorated. In order to completely cover the surface of the phosphor particles with the metal oxide, it is necessary to increase the thickness of the metal oxide film. At this time, however, the degree of light entering and exiting the phosphor particles is reduced, and the fluorescence is reduced. There was a problem that the characteristics deteriorated.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a method for treating phosphor particles capable of enhancing the dispersibility in a resin and enhancing the fluorescence characteristics. An object of the present invention is to provide a light emitting device using the treated phosphor particles.

  In the method for treating phosphor particles according to claim 1 of the present invention, when the surface of the phosphor particles is coated with a metal oxide, the metal complex having a metal constituting the metal oxide as a central atom and fluorine as a ligand. A treatment solution containing ions and water is brought into contact with phosphor particles.

  According to a second aspect of the present invention, in the first aspect, the phosphor particles are formed of a metal oxide.

According to a third aspect of the present invention, in the first or second aspect, the metal complex ion is SiF ₆ ²⁻ .

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the treatment solution contains a Si complex ion having fluorine as a ligand, a Ti complex ion having fluorine as a ligand, and fluorine. It contains at least two or more metal complex ions selected from a Y complex ion as a ligand and a Zr complex ion having fluorine as a ligand.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the metal oxide covering the surface of the phosphor particles is formed with a thickness of 2 to 5 nm.

  The invention of claim 6 is characterized in that, in any one of claims 1 to 5, the concentration of metal complex ions in the treatment solution is 0.01 to 0.2 mol / L.

  A light-emitting device according to claim 7 of the present invention is processed by the light-emitting element having an emission peak at an emission wavelength of 300 nm to 480 nm and the method according to any one of claims 1 to 6 that emits light by absorbing light from the light-emitting element. And a fluorescent material in which the phosphor particles are dispersed in a resin.

  A phosphor particle according to an eighth aspect of the present invention is characterized in that the surface is coated with a metal oxide by the method of any one of the first to sixth aspects.

  According to the present invention, a metal complex ion is brought into contact with phosphor particles by bringing a metal complex ion having a metal constituting the metal oxide as a central atom and fluorine as a ligand into contact with a treatment solution containing water. Fluoride ions produced by reaction with the phosphor particles can be etched on the surface of the phosphor particles to remove defective portions on the surface of the phosphor particles. The surface of the phosphor particles can be coated with a metal oxide generated by the reaction of metal complex ions with water on the surface of the phosphor particles. As a result, the surface of the phosphor particles can be coated with the metal oxide without causing defects again on the surface of the phosphor particles, and the fluorescence characteristics of the phosphor particles can be enhanced. Dispersibility can be improved.

  Hereinafter, the best mode for carrying out the present invention will be described.

In the present invention, when the surface of the phosphor particles is coated with a metal oxide film, the metal oxide preferably has a light transmittance of 85% or more at a wavelength of 250 nm or more. Specifically, a metal oxide selected from SiO ₂ , TiO ₂ , Al ₂ O ₃ , Sc ₂ O ₃ , GeO ₂ , Y ₂ O ₃ , ZrO ₂ , SnO ₂ , or the like, or these metal oxides The composite metal oxide comprised from 2 or more types of these can be mentioned.

The composition of the phosphor particles is arbitrarily set according to the excitation wavelength and emission wavelength. When a white light emitting device is formed in combination with an LED light emitting element, blue light excitation yellow phosphor, ultraviolet light excitation blue A phosphor, an ultraviolet light-excited green phosphor, an ultraviolet light-excited red phosphor, or the like can be used. Specifically, YAG: Ce is used as a blue light-excited yellow phosphor, BaMgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, and ultraviolet light are used as an ultraviolet light-excited blue phosphor. as photoexcitation green phosphor (Zn, Cd) S: Cu , Al and _{BaMgAl 10 O 17: Eu, Mn} , ultraviolet excitation red phosphor as _{Ln 2 O 2 S: Eu (} Ln = Y, La, Gd, Lu, Sc ) And YVO ₄ : Eu.

  The particle diameter of the phosphor particles is preferably in the range of 5 to 300 nm in consideration of dispersibility in the resin. If the particle size is too large, sedimentation in the resin is observed, and the dispersibility tends to deteriorate. On the other hand, if the particle size is too small, it is difficult to remove defects on the surface of the phosphor particles, and there is a tendency for the fluorescence characteristics to deteriorate significantly. Phosphors are generally manufactured by a solid phase method, but phosphor particles having a particle size of 5 to 300 nm can be obtained by a method such as a coprecipitation method or an alkoxide method.

  When the surface of the phosphor particles is coated with the metal oxide film as described above, in the present invention, a metal complex having a metal ion constituting the metal oxide as a central atom and fluorine as a ligand. The treatment can be performed by using a treatment solution containing ions and water and bringing the treatment solution into contact with the surface of the phosphor particles. Specific examples of such metal complex ions include Si complex ions having fluorine as a ligand, Ti complex ions having fluorine as a ligand, Sc complex ions having fluorine as a ligand, and fluorine. Examples thereof include a Ge complex ion having a ligand, a Y complex ion having fluorine as a ligand, a Zr complex ion having fluorine as a ligand, and an Sn complex ion having fluorine as a ligand.

  Here, in a treatment solution containing a metal complex ion and water, the metal complex ion having fluorine as a ligand and water react as follows.

MF _x ^{(x-2n) −} + nH ₂ O⇔MO _n + nF ⁻ +2 nH ⁺
(Where M is a metal ion, x is the coordination number of fluorine to the metal ion, n = (valence of metal ion / 2))
In order to advance the reaction to the right side of this reaction formula, boric acid can be added to the treatment solution containing metal complex ions and water.

When phosphor particles are treated with a treatment solution containing metal complex ions having fluorine as a ligand and water, first, fluoride ions (F ⁻⁾ generated by the reaction of metal complex ions with water as described above. ) Acts on the surface of the phosphor particles, and defects on the surface of the phosphor particles are removed by etching. At this time, when preparing phosphor particles having a particle size of 5 to 300 nm by a method such as a coprecipitation method or an alkoxide method, a firing treatment may be performed at a temperature of 1000 ° C. or higher in order to obtain sufficient fluorescence characteristics. The body particles are necked to form aggregates having a diameter of about 1 to 100 μm, but the necking part is etched by the action of fluoride ions and can be dissociated into phosphor particles having a particle diameter of 5 to 300 nm. is there. The degree of etching varies depending on the composition of the phosphor particle base material, the concentration of metal complex ions in the treatment solution, the temperature of the treatment solution, the treatment time, and the like, but is usually about 1 to 10 nm from the surface.

Next, a metal oxide (MO _n ) film formed by reacting the metal complex ions with water as described above is formed on the surface of the phosphor particles thus etched. The reaction for forming the metal oxide film is likely to occur at the interface between the phosphor particles and the treatment solution, and the metal oxide is deposited so as to uniformly cover the surface of the phosphor particles, and is uniform on the surface of the phosphor particles. A metal oxide film can be formed. The thickness of the metal oxide film can be controlled by the contact time between the phosphor particles and the treatment solution, and a metal oxide film having a uniform thickness can be formed in the range of about 2 to 50 nm. is there.

  Here, the etching reaction and the reaction for forming the metal oxide film are performed in a series of reactions in the treatment solution. Therefore, the metal oxide film is formed on the surface of the phosphor particles from which defects have been removed by etching. Can be formed. And by covering the surface of the phosphor particles with the metal oxide coating in this way, it is possible to suppress the occurrence of defects again on the surface of the phosphor particles, and to improve the fluorescence characteristics of the phosphor particles. It can be held.

  As described above, when the phosphor particles are treated with a treatment solution containing a metal complex ion having fluorine as a ligand and water, the concentration of the metal complex ion having fluorine as a ligand in the treatment solution is 0.01. The range of -0.2 mol / L is preferable, and the range of 0.04-0.1 mol / L is more preferable. When the concentration of metal complex ions is low, the fluoride ion concentration produced by the reaction of metal complex ions with fluorine as a ligand and water is low, so the etching ability of the surface of the phosphor particles decreases, and the phosphor Defects on the surface of the particles cannot be sufficiently removed, there is a possibility that the fluorescence characteristics may be deteriorated, and the phosphor particles do not reach dissociation of aggregates linked by necking, and the phosphor particles to the resin There is a possibility that the dispersibility of the resin may decrease. Conversely, when the concentration of the metal complex ion is high, the reaction between the metal complex ion having fluorine as a ligand and water proceeds rapidly, so that a metal oxide film is locally formed on the surface of the phosphor particles. It is easy to form a uniform metal oxide film, and there is a possibility that defects are locally generated on the surface of the phosphor particles and the fluorescence characteristics are deteriorated. Therefore, in the present invention, the concentration of the metal complex ion having fluorine as a ligand is preferably within the above range.

  In addition, the metal oxide film can be formed in the above range. However, as the thickness of the metal oxide film formed on the surface of the phosphor particles increases, the light of the light emitting element is fluorescent as described later. When fluorescent light is generated by irradiating the body particles, light from the light emitting element is blocked by the metal oxide film and cannot enter the interior of the phosphor particles, which may deteriorate the fluorescence characteristics. For this reason, the thickness of the metal oxide film formed on the surface of the phosphor particles is preferably as thin as possible. And like this invention, when processing a fluorescent substance particle with the process solution containing a metal complex ion and water and forming a metal oxide film, it is possible to form a metal oxide film thinly with a thickness of 5 nm or less Thus, it is possible to prevent the light from entering the inside of the phosphor particles from being blocked by the metal oxide film, and to prevent the fluorescence characteristics from deteriorating. However, if the thickness of the metal oxide film is too thin, the surface of the phosphor particles cannot be completely covered with the metal oxide film, and defects may occur again on the surface of the phosphor particles, which may reduce the fluorescence characteristics. In order to form the metal oxide film uniformly, the thickness of the metal oxide film needs to be 2 nm or more. Therefore, in the present invention, the thickness of the metal oxide film is particularly preferably in the range of 2 to 5 nm.

Various phosphors exemplified above can be used as the phosphor particles, and among these, phosphor particles formed of a metal oxide are preferably used. Specifically, as phosphor particles of metal oxide, YAG: Ce, BaMgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn, Ln ₂ O ₂ S: Eu (Ln = Y, La, Gd, Lu, Sc), YVO ₄ : Eu, and the like can be given.

  The etching action by the fluoride ion generated by the reaction of the metal complex ion having fluorine as a ligand and water has a property of acting more effectively on the metal oxide. Therefore, when the phosphor particles are composed of the metal oxide in this way, the etching effectively acts on the phosphor particles, and it becomes easy to dissociate the aggregate in which the phosphor particles are connected by necking, It is also easy to remove defects on the surface of the phosphor particles. In addition, a metal oxide film formed by the reaction of metal complex ions having fluorine as a ligand with water has a property of being more uniformly and densely formed on the surface of the metal oxide. Therefore, when the phosphor particles are composed of a metal oxide, a uniform and dense metal oxide film can be formed on the surface of the phosphor particles, and the uncoated portion on the surface of the phosphor particles It is possible to more effectively prevent the occurrence of defects again on the surface of the phosphor particles.

In addition, as the metal complex ions having the metal constituting the metal oxide as a central atom and fluorine as a ligand, various types exemplified above can be used, and among them, SiF ₆ ²⁻ is particularly preferable. preferable. In the treatment solution containing the metal complex ion SiF ₆ ²⁻ and water, SiF ₆ ²⁻ and water react as follows.

SiF ₆ ²⁻ + 2H ₂ O⇔SiO ₂ + 6F ⁻ + 4H ⁺
When the treating the surface of the phosphor particles in the processing solution containing SiF ₆ ^2-and water, although the surface of the phosphor particles SiO ₂ film is formed as the oxide film after the etching, SiO ₂ coating Since the denseness is high, it is possible to more effectively prevent the surface of the phosphor particles from being reduced and the defects on the surface of the phosphor particles being reduced.

  Furthermore, as a metal complex ion having a metal constituting the metal oxide as a central atom and fluorine as a ligand, a plurality of types of metal complex ions can be mixed and used at an arbitrary blending ratio. Thus, when multiple kinds of metal complex ions are contained in the treatment solution, the metal oxide film formed on the surface of the phosphor particles is a composite metal oxide film, and the constituent metal element ratio of the composite metal oxide is Since it can be determined by the content ratio of the metal complex ions in the treatment solution, a composite metal oxide film having an arbitrary composition can be easily formed. Thus, when using multiple types of metal complex ions as metal complex ions, Si complex ions having fluorine as a ligand, Ti complex ions having fluorine as a ligand, and Y having fluorine as a ligand. It is preferable to use two or more metal complex ions selected from complex ions and Zr complex ions having fluorine as a ligand. By using these metal complex ions, a uniform and dense complex metal oxide can be formed.

  Here, when the light emitted from the light emitting element is irradiated to the fluorescent light-emitting material prepared by dispersing the fluorescent material particles in the resin as will be described later, due to the difference in the refractive index at the interface between the resin and the fluorescent material particles. Although the reflected light increases, the light that penetrates into the phosphor particles decreases, and the fluorescence characteristics tend to deteriorate, but the refractive index of the resin and the refraction of the phosphor particles are at the interface between the resin and the phosphor particles. When a layer having an intermediate refractive index is formed, reflected light is reduced and fluorescence characteristics can be improved. Therefore, when forming a composite metal oxide film on the surface of phosphor particles using a treatment solution containing multiple types of metal complex ions and water as described above, the type and blending ratio of the metal complex ions are adjusted. Thus, by forming the refractive index of the composite metal oxide film formed on the surface of the phosphor particles between the refractive index of the resin and the refractive index of the phosphor particles, the reflected light can be reduced, and the fluorescence can be reduced. The characteristics can be improved.

  The phosphor particles subjected to the surface treatment as described above are used by being mixed with a transparent resin such as a silicone resin and dispersed in the resin, and a light emitting device having an emission peak at an emission wavelength of 300 nm to 480 nm; A light-emitting device can be formed in combination. Examples of the light emitting element having an emission peak at an emission wavelength of 300 nm to 480 nm include an LED chip that emits ultraviolet light or blue light by a gallium nitride compound semiconductor.

  FIG. 1A shows an example of a light emitting device. A light emitting element 3 such as an LED is mounted on the bottom of a mounting recess 2 of a mounting substrate 1, and a transparent resin in which phosphor particles are dispersed is applied to the mounting recess 2. By filling and curing, the light emitting element 3 is sealed and covered with a fluorescent light emitting body 4 made of a resin in which fluorescent particles are dispersed. The number of mounted light emitting elements 3 may be one or plural. In the light emitting device thus formed, part of the light emitted from the light emitting element 3 is transmitted through the fluorescent light emitter 4 and emitted to the outside, and the other part is emitted from the fluorescent light emitter 4. It is absorbed as primary radiation by the phosphor particles inside. Alternatively, almost the entire light emitted from the light emitting element 3 is absorbed by the phosphor particles. The phosphor particles are excited by absorbing the primary radiation, emit light at a wavelength longer than that of the primary radiation, and are emitted to the outside. At this time, a light emitting device that emits white light can be formed by selecting the type of phosphor particles to be included in the fluorescent light emitter 4 and the light emission wavelength of the light emitting element 3. As described above, the fluorescent light emitter 4 is formed by sealing the light emitting element 3 with the resin in which the phosphor particles are dispersed, and the fluorescent light emitter 4 is formed by molding the resin in which the phosphor particles are dispersed into a plate shape. 1, and the plate-like fluorescent light emitter 4 is arranged on the light emitting element 3 to form a light emitting device, and the light from the light emitting element 3 is transmitted to the fluorescent light emitter 4 as shown in FIG. It can also be made to pass through.

  Here, in preparing the phosphor 4 by curing the resin in which the phosphor particles are dispersed, if the particle size of the phosphor particles is large, the phosphor particles settle due to their own weight within the time when the resin is cured, Although the dispersion of the phosphor particles in the fluorescent light emitter 4 becomes non-uniform, the wavelength conversion by the phosphor particles in the fluorescent light emitter 4 becomes non-uniform, and color unevenness occurs in the light emission of the fluorescent light emitter 4. By treating the phosphor particles with the treatment solution containing the metal complex ion having fluorine as a ligand and water as described above, the aggregates of the phosphor particles can be dissociated into small particles. Accordingly, the dispersibility of the phosphor particles in the resin is improved, and the phosphor particles do not settle while the resin is cured, and light can be emitted without color unevenness. In addition, phosphor particles tend to have defects on the surface due to the reduction in particle size, and there is a tendency for the phosphor properties to deteriorate. By treating with the treatment solution containing the phosphor particles, the defects of the phosphor particles are removed and the phosphor particles are coated with a metal oxide so that the defects do not occur again. Can be prevented. Therefore, the light emitting device using the phosphor particles treated according to the present invention is uniform in wavelength conversion by the phosphor particles in the phosphor 4, and can emit light without color unevenness.

  Next, the present invention will be specifically described with reference to examples.

Example 1
Yttrium nitrate _{(Y (NO 3) 3 ·} 6H 2 O) and 2.7 g, aluminum chloride _{(AlCl 3 · 6H 2 O)} 3.0g, cerium nitrate _{(Ce (NO 3) 3 ·} 6H 2 O) 0 .2 g and dissolved in 100 ml of pure water, 70 mL of a 1 mol / L aqueous ammonia solution was slowly added dropwise to this mixed solution while stirring and allowed to react overnight. After completion of the reaction, the mixture was washed with filtered water, and the obtained powder was heated and dried at 100 ° C. in a dryer. Further, this powder was sintered at 1300 ° C. for 2 hours to obtain YAG: Ce phosphor particles. The average particle diameter of the YAG: Ce phosphor particles was 100 nm.

Next, the YAG: Ce phosphor particles described above were mixed with 50 mL of the processing solution prepared to have the aqueous solution concentration shown in Table 1, and reacted by stirring for 20 minutes at room temperature to form an etching process and formation of a SiO ₂ film. After the treatment, it was washed with filtered water and dried with a dryer at 100 ° C. to obtain YAG: Ce phosphor particles having a SiO ₂ coating on the surface.

20 parts by mass of the SiO ₂ -coated YAG: Ce phosphor particles were mixed and dispersed with respect to 100 parts by mass of a silicone resin (“KE106” manufactured by Shin-Etsu Silicone Co., Ltd.). Then, a resin in which the phosphor particles are dispersed is sealed and cured on the LED light emitting element (emission wavelength: 460 nm) mounted on the mounting substrate, thereby producing a white LED light emitting device (see FIG. 1).

  The output light from the white LED light-emitting device thus obtained was white light having no color unevenness and a color temperature of about 4730 K, and its efficiency was 25 ml / W.

(Example 2)
The treatment solution 50mL prepared so that the concentration of the aqueous solution of Table 1, YAG was prepared in the same manner as in Example 1 were mixed with Ce phosphor particles, the reaction stirred for 20 minutes at room temperature, an etching treatment and SiO ₂ after performing the formation process of -TiO ₂ coating, filtered washed with water and dried at a 100 ° C. _oven, YAG was coated SiO 2 -TiO ₂ film on the surface: to obtain a Ce phosphor particles.

Then, using this SiO ₂ —TiO ₂ coated YAG: Ce phosphor particles, a white LED light emitting device was produced in the same manner as in Example 1. The output light from the white LED light-emitting device thus obtained was white light with no color unevenness and a color temperature of about 4730 K, and its efficiency was 26 ml / W.

(Comparative example)
YAG: Ce phosphor particles prepared in the same manner as in Example 1 were mixed with an HF aqueous solution diluted with HF to be 0.1% by mass, stirred at room temperature for 1 hour, and subjected to an etching treatment to perform etching. After completion, it was washed with filtered water. Next, the YAG: Ce phosphor particles were dispersed in 50 ml of isopropanol in which 1.0 g of tetraethoxysilane was dissolved, and the mixture was stirred at room temperature for 1 hour to react to form a SiO ₂ film. After completion of the reaction, it was washed with filtered water and dried with a dryer at 100 ° C. to obtain YAG: Ce phosphor particles with a SiO ₂ coating on the surface.

A white LED light-emitting device was produced in the same manner as in Example 1 using the SiO ₂ -coated YAG: Ce phosphor particles. The output light from the white LED light-emitting device thus obtained was white light having a color temperature of about 4730 K. Color unevenness was observed in several places, and the efficiency was 22 ml / W.

An example of a light-emitting device is shown, and (a) and (b) are cross-sectional views, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting board 3 Light emitting element 4 Fluorescent light emitter

Claims (8)

  When coating the surface of the phosphor particles with a metal oxide, a treatment solution containing a metal complex ion having a metal constituting the metal oxide as a central atom and fluorine as a ligand and water is brought into contact with the phosphor particles. And a method for treating phosphor particles.   The method for treating phosphor particles according to claim 1, wherein the phosphor particles are formed of a metal oxide. The method for treating phosphor particles according to claim 1, wherein the metal complex ion is SiF ₆ ²⁻ .   The treatment solution includes a Si complex ion having fluorine as a ligand, a Ti complex ion having fluorine as a ligand, a Y complex ion having fluorine as a ligand, and Zr having fluorine as a ligand. The method for treating phosphor particles according to any one of claims 1 to 3, comprising at least two or more metal complex ions selected from complex ions.   The method for treating phosphor particles according to any one of claims 1 to 4, wherein a metal oxide covering the surface of the phosphor particles is formed to a thickness of 2 to 5 nm.   The method for treating phosphor particles according to claim 1, wherein the treatment solution has a metal complex ion concentration of 0.01 to 0.2 mol / L.   A light emitting device having an emission peak at an emission wavelength of 300 nm to 480 nm, and a fluorescent light emission in which phosphor particles treated by the method of any one of claims 1 to 6 that emit light by absorbing the light of the light emitting device are dispersed in a resin A light emitting device comprising a body. A phosphor particle, the surface of which is coated with a metal oxide by the method according to claim 1.

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