JP2019081894A - Rare earth aluminate phosphor and method for producing the same - Google Patents

Abstract

To provide a rare earth aluminate phosphor capable of increasing a saturation luminance and a method for producing the rare earth aluminate phosphor.SOLUTION: A rare earth aluminate phosphor contains at least one rare earth element Ln selected from a group consisting of Y, La, Lu, Gd and Tb, Ce, Al, and at least one element M1 selected from Ga and Sc as needed. The rare earth aluminate phosphor has a composition of a rare earth aluminate in which a total molar ratio of the rare earth element Ln and Ce is 3, a total molar ratio of Al and the element M1 is a product of 5 and a variable k that is 0.95 or greater and 1.05 or less, and a molar ratio of Ce is a product of a variable n that is 0.003 or greater and 0.017 or less and 3. An emission peak wavelength λ(nm) at the excitation wavelength 450 nm and the variable n satisfy the relational expression: λ≥1590n+531.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rare earth aluminate phosphor and a method of manufacturing the same.

  Light emitting diodes (Light Emitting Diode: hereinafter also referred to as “LED”) and semiconductor laser diodes (Laser Diode: hereinafter also referred to as “LD”) together with light emitting devices for vehicles and general illumination, liquid crystal display devices DESCRIPTION OF RELATED ART As a fluorescent substance used for a backlight and a light source device for projectors, yttrium aluminum garnet type fluorescent substance (It is also called "YAG type fluorescent substance" hereafter) containing rare earths, such as yttrium, is known. In addition, lutetium aluminum garnet-based phosphors containing lutetium (hereinafter also referred to as "LuAG-based phosphors") are also known. In the present specification, a phosphor of an aluminate having a garnet crystal structure containing a rare earth element including a YAG-based phosphor and a LuAG-based phosphor is referred to as a rare earth aluminate phosphor.

  Among the rare earth aluminate phosphors, the Ce-activated rare earth aluminate phosphor is excited by irradiation of particle beams such as electron beam, vacuum ultraviolet light and blue light or electromagnetic waves and emits yellow to green light. . Since the rare earth aluminate phosphor activated with Ce has a short afterglow, a clear image can be obtained. Since the rare earth aluminate phosphor activated with Ce has a short afterglow, it is used, for example, in a light source device for a projector shown in Patent Document 1.

JP, 2015-138168, A

However, in the light emitting device or the light source device, when the light density of the excitation light becomes higher than a certain level, the light emission process of the phosphor can not catch up with the increase of the excitation energy density when the light density of the excitation light The body tends to cause luminance saturation. Since the laser light source has a very high light density, when the laser output is increased, the rare earth aluminate phosphor irradiated with a specific laser output causes luminance saturation, and the emission intensity drops sharply. FIG. 5 shows the relationship between the laser output for irradiating the phosphor and the emission intensity of the phosphor when the semiconductor laser is irradiated to the phosphor, and is an image diagram showing how the luminance of the phosphor with respect to the laser output is saturated. . As shown in FIG. 5, in the rare earth aluminate phosphor activated with Ce, the emission intensity linearly increases when the laser output as excitation light increases, but the emission intensity increases rapidly when the saturation luminance is exceeded. descend. Therefore, there is a demand for a rare earth aluminate phosphor having a linearly large increase in the output of emission intensity with respect to the input of excitation light and having high saturation luminance.
Therefore, an object of the present invention is to provide a rare earth aluminate phosphor that can increase saturation luminance and a method for producing the same.

  The means for solving the problems includes the following aspects.

The first aspect of the present invention is selected from at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, Ce, Al, and optionally Ga and Sc. Contains at least one element M1,
The molar ratio of the total of the rare earth elements Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is the product of 5 and a variable k of 0.95 to 1.05, and the molar ratio of Ce is , A composition of a rare earth aluminate which is the product of a variable n and a value of 0.003 or more and 0.017 or less,
It is a rare earth aluminate phosphor characterized in that an emission peak wavelength λ _p (nm) at an excitation wavelength of 450 nm and the variable n satisfy the relation λ _p 151590 n + 531.

The second aspect of the present invention is a compound containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound containing Ce, a compound containing Al, and, as required, The compound containing at least one element M1 selected from Ga and Sc, the molar ratio of the total of the rare earth elements Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is 5, Ce A first firing step of firing the first raw material mixture prepared by adjusting the feed composition and mixing so that the product of the variable n and the molar ratio is 0.003 or more and 0.017 or less and the first firing product; ,
A compound containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound containing Ce, a compound containing Al, and optionally Ga and In the compound containing at least one element M1 selected from Sc, the molar ratio of the total of the rare earth elements Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is 5, and the molar ratio of Ce The second firing step is to obtain a second fired product by firing a mixture containing the second raw material mixture in which the feed composition is adjusted and mixed such that the product of the variables n and 3 is 0.003 or more and 0.017 or less. A method of producing a rare earth aluminate phosphor, the method comprising

  According to one aspect of the present invention, it is possible to provide a rare earth aluminate phosphor capable of increasing saturation luminance and a method of manufacturing the same.

FIG. 1 shows that the molar ratio of Ce in each composition of the rare earth aluminate phosphor according to Examples 1-1 to 1-3 and the rare earth aluminate phosphor according to Comparative Examples 1-1 to 1-3 is a rare earth element. It is the graph which plotted the relationship between the variable n divided by the molar ratio 3 of the sum total of Ln and Ce, and the emission peak wavelength (nm) of each rare earth aluminate fluorescent substance. FIG. 2 relates to the rare earth aluminate phosphor according to Example 1-2 and the rare earth aluminate phosphor according to Comparative Example 1-2, and the output (LD output) of the laser diode irradiated to the phosphor and each fluorescence It is a graph which shows a relation with luminescence intensity of a body. FIG. 3 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Example 1-2. FIG. 4 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Comparative Example 1-2. FIG. 5 is an image diagram showing the relationship between the output (laser output) of the laser light irradiated to the phosphor and the emission intensity of the phosphor with respect to the input of the laser light.

  Hereinafter, the rare earth aluminate phosphor according to the present invention and the method for producing the same will be described based on the embodiments. However, the embodiment shown below is an illustration for embodying the technical idea of the present invention, and the present invention is not limited to the following rare earth aluminate phosphor and a method of manufacturing the same. The relationship between the color name and the chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, etc. conform to JIS Z8110.

Rare Earth Aluminate Phosphor The rare earth aluminate phosphor according to the first embodiment comprises at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, Ce and Al. And the molar ratio of the total of the rare earth elements Ln and Ce is 3, and the total molar ratio of Al and the element M1 is 5 and 0, at least one element M1 optionally selected from Ga and Sc. It has a composition of a rare earth aluminate which is a product of a variable k of .95 or more and 1.05 or less and a molar ratio of Ce is a product of a variable n of 3 or more and 0.003 or more and 0.017 or less, and an excitation wavelength The emission peak wavelength λ _p (nm) at 450 nm and the variable n satisfy the relational expression λ _p 151590 n + 531.

  The rare earth aluminate phosphor has a variable n of 0.003 or more and 0.017 or less obtained by dividing the molar ratio of Ce by the molar ratio 3 of the total of the rare earth element Ln and Ce in the composition of the phosphor. The emission peak wavelength λp (nm) at an excitation wavelength of 450 nm and the variable n satisfy the relational expression λp ≧ 1590n + 531, and the emission intensity linearly increases with the output of the excitation light irradiated to the phosphor , High saturation brightness. That is, when the emission peak wavelength λp at the excitation wavelength of 450 nm is a constant value, the value of the variable n is the molar ratio of Ce in the composition of the rare earth aluminate phosphor divided by the molar ratio 3 of the total of the rare earth elements Ln and Ce In the rare earth aluminate phosphor having a small value of the variable n so as to satisfy the relational expression λp ≧ 1590 n + 531, the luminance saturation is relaxed and the saturation luminance of the rare earth aluminate phosphor becomes high. In the composition of the rare earth aluminate phosphor, as the variable n decreases, the saturation luminance increases, but the emission peak wavelength of the rare earth aluminate phosphor tends to be short. In the rare earth aluminate phosphor, the light emission peak wavelength λp (nm) and the variable n satisfy the relational expression λp ≧ 1590n + 531. That is, even if the molar ratio of Ce contained in the composition of the phosphor is reduced in order to increase the saturation luminance, it is possible to suppress the shift of the emission peak wavelength to the short wavelength side. In the composition of the rare earth aluminate phosphor, if the variable n is less than 0.003, the activation amount of Ce is too small to obtain sufficient light emission luminance. In the composition of the rare earth aluminate phosphor, when the variable n exceeds 0.017, the activation amount of Ce becomes too large and concentration quenching tends to occur, and the light emission peak wavelength λp and the variable n have a relational expression λp Even when ≧ 1590 n + 531 is satisfied, the saturated luminance may not be able to be increased.

  In the composition of the rare earth aluminate phosphor, the variable n is preferably 0 in order to improve the luminance saturation of the emission intensity with respect to the input of the excitation light when the rare earth aluminate phosphor is used in a light emitting device. It is in the range of 0.003 or more and 0.016 or less, and more preferably in the range of 0.003 or more and 0.015 or less.

The composition of the rare earth aluminate phosphor is preferably represented by the following formula (I-1).
(Ln _1-n Ce _n ) ₃ (Al _1-m M1 _m ) _{5 k} O ₁₂ (I-1)
(In the formula (I-1), Ln is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd and Tb, and M1 is at least one element selected from Ga and Sc And k, n and m are numbers satisfying 0.95 ≦ k ≦ 1.05, 0.003 ≦ n ≦ 0.017, and 0 ≦ m ≦ 0.02, respectively.)
The rare earth aluminate phosphor having the composition represented by the formula (I-1) is one in which the emission peak wavelength λp (nm) at an excitation wavelength of 450 nm and the variable n satisfy the relational expression λp ≧ 1590n + 531, Elongation of the emission intensity with respect to the input of the excitation light irradiated to the rare earth aluminate phosphor is linearly large, and has high saturation luminance.

  In the composition of the rare earth aluminate phosphor, the rare earth element Ln is an element constituting a crystal structure of a garnet structure together with Al and at least one element M1 selected from Ga and Sc as required. In the composition of the rare earth aluminate phosphor, the rare earth element Ln preferably includes at least one selected from the group consisting of Y, Lu and Tb, and more preferably includes at least one selected from Y and Lu, More preferably, Y is included. When the rare earth element Ln contains Y in the composition of the rare earth aluminate phosphor, an emission spectrum including yellow can be obtained.

  In the composition of the rare earth aluminate phosphor, Ce is an activating element, and a variable n is an activating amount of the activating element. In the composition of the rare earth aluminate phosphor, a variable n is 0.003 which is a value obtained by dividing the molar ratio of Ce contained in the rare earth aluminate phosphor by the molar ratio 3 of the total of the rare earth elements Ln and Ce. It is preferable that it is the range of 0.017 or less. In the composition of the rare earth aluminate phosphor, when the emission peak wavelength λp (nm) at the excitation wavelength of 450 nm and the variable n satisfy the relational expression λpp1590n + 531, the variable n satisfies 0.003 ≦ n ≦ 0. .017, preferably 0.003 6 n 0.01 0.016, more preferably 0.003 0.01 n 0.01 0.015.

  In the composition of the rare earth aluminate phosphor, at least one element M1 selected from Ga and Sc contained as necessary forms a crystal structure of a garnet structure with Al. The element M1 more preferably contains Ga. In the composition of the rare earth aluminate phosphor, the variable m is a value obtained by dividing the molar ratio of the element M1 by the molar ratio 5 k of the total of Al and the element M1. The variable m may be 0 or 0 <m ≦ 0.02. In the composition of the rare earth aluminate phosphor, when the variable m is 0 ≦ m ≦ 0.02, it can be a rare earth aluminate phosphor having a stable garnet structure and having a desired light emission luminance. .

  In the composition of the rare earth aluminate phosphor, the variable k is a coefficient of the molar ratio 5 of the total of Al and the element M1, and in the composition of the rare earth aluminate phosphor, the molar ratio of the total of Al and the element M1 is It may be less than 5 or more than 5. The variable k is preferably 0.95 or more and 1.05 or less, more preferably 0.98 or more and 1.02 or less, and still more preferably 0.99 or more and 1.01 or less from the viewpoint of the stability of the crystal structure. .

The rare earth aluminate phosphor preferably has an average particle size (Fisher sub-sieve's number) of 15 μm or more as measured by the FSSS method (Fisher sub-sieve sizer). The rare earth aluminate phosphor has a desired high luminance when the average particle size measured by the FSSS method is 15 μm or more.
The average particle diameter of the rare earth aluminate phosphor measured by the FSSS method is more preferably 16 μm or more, still more preferably 17 μm or more, and still more preferably 18 μm or more. The average particle diameter of the rare earth aluminate phosphor is preferably large, but the saturated luminance to the input of the excitation light irradiated to the rare earth aluminate phosphor is high, and uniform by excitation of laser light having a high light density. In order to obtain a color tone, the average particle diameter of the rare earth aluminate phosphor measured by the FSSS method may be 50 μm or less, preferably 40 μm or less.

  The rare earth aluminate phosphor can have a plurality of layers including the composition of the rare earth aluminate phosphor in a sectional view of phosphor particles. The plurality of layers in the cross-sectional view of the rare earth aluminate phosphor particles are formed by the first baked product obtained by the first baking step and the at least one second manufactured using the first baked product according to the manufacturing method described later. It can be formed by a firing process.

Method for producing rare earth aluminate phosphor The method for producing a rare earth aluminate phosphor according to the second embodiment comprises at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb. A compound containing Ce, a compound containing Ce, a compound containing Al, and a compound containing at least one element M1 optionally selected from Ga and Sc, the molar ratio of the total of the rare earth elements Ln and Ce being 3 , The molar ratio of the total of Al and the element M1 is 5, and the preparation composition is adjusted and mixed so that the molar ratio of Ce is the product of variable n and 0.003 to 0.017, A first firing step of firing the raw material mixture to obtain a first fired product, the first fired product, and at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb Turn A compound containing Ce, a compound containing Al, and a compound containing at least one element M1 optionally selected from Ga and Sc, the molar ratio of the total of the rare earth elements Ln and Ce being 3 , The molar ratio of the total of Al and the element M1 is 5, and the preparation composition is adjusted and mixed so that the molar ratio of Ce is the product of variable n and 0.003 to 0.017 or less And firing at least one second firing step to obtain a second fired product.

Preparation step of first raw material mixture or second raw material mixture The raw material is a compound containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound containing Ce, Al It is possible to use a compound containing, and a compound containing at least one element M1 optionally selected from Ga and Sc. These compounds are used to prepare a first raw material mixture or a second raw material mixture. In the present specification, the first raw material mixture refers to a raw material mixture which does not include the first baked product or the second baked product described later obtained by baking the first raw material mixture. Moreover, in this specification, a 2nd raw material mixture means the raw material mixture containing a 1st baked matter or a 2nd baked matter.
The compound containing rare earth element Ln, the compound containing Ce, the compound containing Al, and the compound containing at least one element M1 selected from Ga and Sc include oxides and metal salts. Examples of metal salts include oxalate, carbonate, chloride, nitrate or sulfate. The compound used as a raw material may be in the form of a hydrate.
As an oxide, specifically, Y ₂ O ₃ , La ₂ O ₃ , Lu ₂ O ₃ , Gd ₂ O ₃ , Tb ₄ O ₇ , CeO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , Sc ₂ O ₃ is mentioned.
Specific examples of the metal salt include YCl ₃ , Y ₂ (C ₂ O ₄ ) ₃ , Y ₂ (CO ₃ ) ₃ , Y (NO ₃ ) ₃ , Y ₂ (SO ₄ ) ₃ , LaCl ₃ and La. _{2 (C 2 O 4) 3} , La 2 (CO 3) 3, La (NO 3) 3, La 2 (SO 4) 3, LuCl 3, Lu 2 (C 2 O 4) 3, Lu (NO 3) ₃ , Lu ₂ (SO ₄ ) ₃ , GdCl ₃ , TbCl ₃ , CeCl ₃ , Ce ₂ (SO ₄ ) ₃ , AlCl ₃ , Al (NO ₃ ) ₃ , Al ₂ (SO ₄ ) ₃ , GaCl ₃ , Ga _{NO 3) 3, ScCl 3,} Sc (NO 3) 3 and the like.

The first raw material mixture or the second raw material mixture has, as a feed composition, a molar ratio of the total of the rare earth elements Ln and Ce of 3, a molar ratio of the total of Al and the element M1 of 5, Ce Each raw material is adjusted so that the molar ratio is a product of variable n and 3 of 0.003 or more and 0.017 or less. Preferably, the first raw material mixture or the second raw material mixture is prepared by adjusting the compound containing Ce so that the molar ratio of Ce is the product of variable n and 3 of 0.003 or more and 0.016 or less. More preferably, the compound containing Ce is adjusted such that the molar ratio of Ce is the product of variable n and 0.003 or more and 0.015 or less.
When the compound containing the element M1 is used as the first raw material mixture or the second raw material mixture, the product of the variables m and 5 in which the molar ratio of the element M1 is 0 or more and 0.02 or less as the feed composition It is preferable to adjust and mix each raw material so that it may become. The first raw material mixture or the second raw material mixture may not contain the compound containing the element M1.

It is preferable that each raw material is mixed so that a 1st raw material mixture or a 2nd raw material mixture may be represented by following formula (I-2) for a preparation composition.
(Ln _1-n Ce _n ) ₃ (Al _1-m M _{1 m} ) ₅ O ₁₂ (I-2)
(Wherein, L n is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd and Tb, and M 1 is at least one element selected from Ga and Sc) And n and m are numbers satisfying 0.003 ≦ n ≦ 0.017 and 0 ≦ m ≦ 0.02, respectively.)
The first raw material mixture or the second raw material mixture is a rare earth aluminate having a desired light emission luminance by mixing the respective raw materials as the feed composition is represented by the formula (I-2). A phosphor can be obtained. The first raw material mixture or the second raw material mixture preferably contains a compound containing Y.

  The first raw material mixture or the second raw material mixture contains 0.5% by mass or more and 10% by mass or less of a compound containing at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Mn as a flux. Is preferred. It is preferable that the first raw material mixture or the second raw material mixture in the first baking step and / or the second baking step contains the compound in an amount of 0.5% by mass or more and 10% by mass or less as the flux. When the first raw material mixture or the second raw material mixture contains a flux, the reaction between the raw materials is promoted, and the solid phase reaction tends to progress more uniformly. This is because the temperature at which the first raw material mixture or the second raw material mixture is fired is approximately the same as or higher than the formation temperature of the liquid phase of the halide used as a flux. Is considered to be promoted.

The compound containing at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Mn, which is used as a flux, is preferably a halide. Among the halides, the compound used as the flux is preferably fluoride and / or chloride, more preferably fluoride. The compound used as the flux is more preferably BaF ₂ . By using BaF ₂ as the flux, the garnet crystal structure of the rare earth aluminate phosphor is stabilized, and the composition of the garnet crystal structure is easily formed. When the total amount of the first raw material mixture or the second raw material mixture containing flux is 100% by mass, the compound used as the flux has a content of 0.5% by mass or more and 10% by mass or less of the compound as the flux Is preferred. If the content of the flux in the first raw material mixture or the second raw material mixture is in the above range, the reaction between the raw materials is further promoted, and the solid phase reaction proceeds more uniformly, and has the target composition. It is easy to obtain rare earth aluminate phosphors. When the total amount of the first raw material mixture or the second raw material mixture containing the flux is 100% by mass, the content of the flux in the first raw material mixture or the second raw material mixture is more preferably 1.0. % By mass or more and 8.0% by mass or less, more preferably 1.5% by mass or more and 7.0% by mass or less.

  The first raw material mixture or the second raw material mixture is adjusted to have a desired feed composition, and after weighing each raw material, a dry grinder such as a ball mill, vibration mill, hammer mill, roll mill, jet mill, etc. It may be ground and mixed using a mortar, or may be ground and mixed using a mortar and a pestle etc. For example, it may be mixed using a mixer such as a ribbon blender, a Henschel mixer, a V-type blender, etc. Grinding and mixing may be performed using both a mixer and a mixer. Also, the mixing may be dry mixing, or may be wet mixing with the addition of a solvent or the like. The mixing is preferably dry mixing. This is because the dry process can reduce the process time more than the wet process, leading to an improvement in productivity.

First Firing Step The first firing step is a step of firing a first raw material mixture to obtain a first fired product. In the present specification, the first fired product refers to a product obtained by firing the first raw material mixture not containing the fired product. In the first firing step, the raw material mixture is placed in a crucible or boat made of a carbon material such as graphite, boron nitride (BN), aluminum oxide (alumina), tungsten (W), or molybdenum (Mo). It can be fired. For the first firing, for example, an electric furnace, a gas furnace or the like can be used.

  The firing temperature in the first firing step is preferably 1400 ° C. or more and 1800 ° C. or less, more preferably 1450 ° C. or more and 1700 ° C. or less, from the viewpoint of the stability of the crystal structure of the first fired product obtained.

  The firing time in the first firing step differs depending on the temperature rising rate, heat treatment atmosphere, etc., and is preferably 1 hour or more, more preferably 3 hours or more, further preferably 5 hours or more after reaching the firing temperature. It is 20 hours or less, more preferably 18 hours or less, and further preferably 15 hours or less. The firing time in the first firing step is preferably 5 hours or more and 20 hours or less after reaching the firing temperature, and more preferably 8 hours or more and 15 hours or less.

The atmosphere in the first firing step is preferably a reducing atmosphere. The reducing atmosphere is preferably a nitrogen atmosphere containing reducing hydrogen gas. In a reducing atmosphere, hydrogen gas is preferably 1% by volume or more, more preferably 5% by volume or more, and still more preferably 10% by volume or more. In the reducing atmosphere, the nitrogen gas is preferably 70% by volume or more, more preferably 80% by volume or more, and still more preferably 90% by volume or more. The first raw material mixture has high reactivity in an atmosphere with high reducing power, and can be fired under atmospheric pressure without pressurization to obtain a first fired product. Also, in an atmosphere with high reducing power By calcining the first raw material mixture, tetravalent Ce (Ce ^{4 +} ) is reduced to trivalent Ce (Ce ^{3 +} ), and the proportion of trivalent Ce that contributes to light emission in the first calcined product Can be obtained.

Dispersion Treatment Step It is preferable that the obtained first baked product is subjected to dispersion treatment including wet dispersion, wet sieving, and sedimentation classification. Specifically, it is preferable to wet-disperse the obtained first baked product, remove coarse particles by wet sieving, and then carry out sedimentation classification to remove fine particles. The sedimentation classification may be performed twice or more, and the number of the sedimentation classification is preferably 20 times or less from the viewpoint of improving the productivity. By the dispersion process, the particle size of the obtained first fired product can be made uniform. Water can be used as an aqueous medium used for wet dispersion. For wet dispersion, a dispersion medium such as alumina balls or zirconia balls may be used. The time of wet dispersion is preferably 4 hours to 50 hours, more preferably 5 hours to 40 hours, in consideration of productivity.

Acid Cleaning Treatment Step The obtained first baked product is preferably subjected to an acid cleaning treatment. It is more preferable that the first baked product is subjected to an acid washing treatment after the dispersion treatment. The first baked product is subjected to an acid cleaning treatment to remove impurities attached to the surface of the first baked product. It is preferable to use an aqueous solution of hydrochloric acid for acid cleaning because it is easy to obtain and inexpensive. The concentration of hydrochloric acid contained in the aqueous hydrochloric acid solution is preferably a concentration that removes impurities on the surface and does not affect the crystal structure of the first baked product, and is preferably 1% by mass to 20% by mass. More preferably, it is 5% by mass or more and 18% by mass or less.

Second firing step The second firing step includes a first fired product, a compound including at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound including Ce, and Al. The compound and the compound containing at least one element M1 optionally selected from Ga and Sc, wherein the molar ratio of the total of the rare earth elements Ln and Ce is 3, and the molar ratio of the total of Al and the element M1 The mixture containing the second raw material mixture is prepared by adjusting the feed composition and mixing so that the molar ratio of Ce is 5 and the product of the variable n of 0.003 or more and 0.017 or less and the variable n is 3. It is a process of obtaining two baked products.

  In the present specification, the second firing step refers to firing the first fired product and the second raw material mixture to obtain a second fired product. The fired product in the second firing step is the first fired product obtained by firing the first raw material mixture, but the second fired obtained by firing the first baked product and the second raw material mixture It may be a thing. The second firing step is performed at least once. The second firing step is a rare earth aluminate which has high saturation luminance when used in a light emitting device and can suppress the shift of the emission peak wavelength to the short wave side even if the molar ratio of Ce in the composition of the phosphor is reduced. In order to obtain a salt phosphor, it is preferable to carry out twice or more. It is more preferable to perform a 2nd baking process twice from a viewpoint of a productivity improvement.

The second baked product obtained by the second baking step forms a layered baked product of one layer by one second baking process with the first baked product as a core. When the second firing step is repeated twice, a second fired product in which the layered fired product of one layer is formed by the first firing step is obtained by using the first fired product as a core, and by the second firing step, With the first baked product as the core, the second baked product of the second layer is formed on the surface of the second baked product of the first layer.
In the second firing step, a second raw material mixture including the first fired product and the raw material mixture is fired to form a layered second fired product of one layer by the second firing step with the first fired product as a core. The second baking process may be performed twice or more, and two or more layers of second baking products may be formed for each second baking process with the first baking product as a core. . In the present specification, when the second baked product is repeated twice or more times, for example, even a baked product obtained by the second baking process is referred to as a second baked product, for example, the third baked second product. Even a fired product obtained by the firing process is referred to as a second fired product.
The obtained rare earth aluminate phosphor is a rare earth aluminate in a sectional view of phosphor particles obtained by the first baked product obtained by the first baking process and at least one second baking process using the first baked product. It can have multiple layers comprising the composition of the salt phosphor.
By performing firing several times to obtain a phosphor having a relatively large particle size, it is possible to increase the crystallinity of the phosphor rather than obtaining a phosphor having a relatively large particle size by firing only once. As such, it is possible to obtain a phosphor suitable as a phosphor for LD, which requires particularly high crystallinity.

  By performing the second firing step using the first fired product obtained by the first firing step as the core, it is speculated that a rare earth phosphor with a relatively large particle diameter in which Ce is diffused in the core can be obtained . When the second firing step is performed with the first fired product as the core, Ce is more diffused in the garnet structure of the first fired product to be the core, and a more homogeneous fired product is obtained in the first fired product core. It is guessed. When Ce is segregated, the local increase in the concentration of Ce may cause adverse effects on the light emission characteristics due to the interaction between the activator Ce and another Ce. The rare earth aluminate phosphor consisting of the second fired product obtained by the manufacturing method according to the second embodiment is a rare earth aluminate fluorescent light without causing an adverse effect on the light emission characteristics due to the local increase of the concentration of Ce. The molar ratio of Ce in the composition of the body can be reduced. Moreover, it is estimated that the second fired product obtained by the manufacturing method according to the second embodiment is more homogeneous without Ce segregating in the core which is the first fired product. Therefore, even when the molar ratio of Ce in the composition is reduced, the light emission peak wavelength is not shortened, that is, the fluctuation of the color tone can be suppressed, and the saturation luminance can be increased. In other words, the saturation luminance can be increased by reducing the molar ratio of Ce with the same color tone. Further, according to the manufacturing method of the second embodiment, a more uniform second baked product can be obtained even if the molar ratio of Ce in the composition is reduced. Therefore, in the rare earth aluminate phosphor made of the second baked product, the variable n and the emission peak wavelength λp (nm) of the rare earth aluminate phosphor at an excitation wavelength of 450 nm satisfy the relational expression λp ≧ 1590n + 531.

  The second raw material mixture used in the second baking step uses a part of the raw material mixture obtained in the preparation step as the first raw material mixture in the first baking step, and the second raw material mixture in the second baking step A part of H may be used as a second raw material mixture. The second raw material mixture is prepared separately from the first raw material mixture obtained in the preparation step, similarly to the first raw material mixture obtained in the preparation step, using the second raw material mixture whose feed composition is adjusted. The second mixture of raw materials newly obtained may be used. It is preferable that the raw material of the 2nd raw material mixture used in a 2nd baking process uses the same raw material as the raw material of the 1st raw material mixture used at the preparation process. The second raw material mixture used in the second firing step is preferably adjusted to be similar to the feed composition of the first raw material mixture in the preparation step. It is preferable that the 2nd raw material mixture used in a 2nd baking process is adjusted so that it may become a preparation composition represented by said Formula (I-2). It is preferable that the 2nd raw material mixture used in a 2nd baking process contains a flux similarly to the 1st raw material mixture obtained in a preparatory process. As the flux, the same flux and amount as the flux contained in the first raw material mixture in the preparation step can be used. The 2nd raw material mixture used in a 2nd baking process can mix each raw material by the method similar to the 1st raw material mixture in a preparatory process. The second firing can be performed by placing a mixture containing the first fired material and the second raw material mixture in a crucible or a boat similar to the first firing.

  In the second firing step, the mass ratio of the first fired product or the second fired product to 100% by mass of the second raw material mixture is preferably in the range of 20% by mass to 83% by mass, and more preferably 22% % Or more and 77% by mass or less, more preferably 25% by mass or more and 67% by mass or less, and still more preferably 29% by mass or more and 59% by mass or less.

  In the second firing step, the mixture containing the first fired product or the second fired product and the second raw material mixture can be placed in a crucible or a boat of the same material as the first firing step to perform the second firing. . For the second firing, for example, an electric furnace, a gas furnace or the like can be used.

  The firing temperature in the second firing step is preferably 1400 ° C. or more and 1800 ° C. or less, more preferably 1450 ° C. or more and 1700 ° C. or less from the viewpoint of the stability of the crystal structure of the second fired product to be obtained.

  The firing time in the second firing step differs depending on the temperature rising rate, heat treatment atmosphere, etc., and is preferably 1 hour or more, more preferably 3 hours or more, further preferably 5 hours or more after reaching the firing temperature. It is 20 hours or less, more preferably 18 hours or less, and further preferably 15 hours or less. The firing time in the second firing step is preferably 5 hours or more and 20 hours or less after reaching the firing temperature, and more preferably 8 hours or more and 15 hours or less.

  The atmosphere in the second firing step is preferably a reducing atmosphere, and the reducing atmosphere is more preferably the second firing in the same atmosphere as the reducing atmosphere in the first firing step.

Dispersion treatment process The second fired product obtained is wet-dispersed in the same manner as the first fired product, and after the coarse particles are removed by wet sieving, it is possible to carry out a dispersion process in which fine particles are removed by sedimentation classification. preferable. The sedimentation classification may be carried out a plurality of times, and the number of sedimentation classification may be carried out twice or more in order to make the particle diameter of the obtained second fired product uniform, and is 20 times or less from the viewpoint of improving productivity. Is preferred. The dispersion treatment step may be performed after the first firing step or may be performed after the second firing step. The dispersion treatment step may be performed only after the second firing step without performing after the first firing step. When the second firing step is performed twice or more, the dispersion treatment may be performed after the second firing step every second firing step performed twice or more, and the second firing step is repeated several times, Dispersion treatment may be performed after the last second firing step.

Acid Cleaning Treatment Step The obtained second baked product is preferably subjected to an acid washing treatment as in the first baked product. It is more preferable that the second baked product is subjected to an acid washing treatment step after the dispersion treatment step. The second baked product is subjected to an acid cleaning treatment to remove impurities attached to the surface of the second baked product. The acid washing step may be performed after the first firing step or may be performed after the second firing step. The acid washing treatment step may be performed only after the second firing step without performing after the first firing step. When the second firing step is performed twice or more, the acid cleaning treatment step may be performed after the second firing step for every second firing step performed twice or more, and a plurality of second firing steps are continuously performed. After the final second baking step, an acid washing treatment step may be performed.

The rare earth aluminate phosphor according to the first embodiment or the rare earth aluminate phosphor obtained by the manufacturing method according to the second embodiment combines the light emitted from the light emitting element with the light emitting element. It becomes possible to construct a light emitting device which emits light of mixed color converted from light from the light emitting element and wavelength-converted by the rare earth aluminate phosphor. As the light emitting element, for example, a light emitting element which emits light in a wavelength range of 350 nm to 500 nm can be used. The light-emitting element, for example, it is possible to use a semiconductor light emitting device using nitride semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1). By using a semiconductor light emitting element as the excitation light source, it is possible to obtain a stable light emitting device that is highly efficient, has high linearity with respect to the input, and is resistant to mechanical shock.

  The rare earth aluminate phosphor according to the first embodiment or the rare earth aluminate phosphor obtained by the manufacturing method according to the second embodiment is emitted from the laser light source in combination with the laser light source, and is a dichroic mirror It is possible to configure a light source device for a projector that converts excitation light collected by a collimating optical system. The rare earth aluminate phosphor has a light emission peak wavelength even when the molar ratio of Ce in the composition is reduced to increase the saturation luminance with respect to the input of excitation light having a large light density like a laser light source. The shift to the short wave side can be suppressed.

  A rare earth aluminate phosphor according to the first embodiment or a rare earth aluminate phosphor obtained by the manufacturing method according to the second embodiment includes a phosphor unit having the rare earth aluminate phosphor. The present invention can be applied to a light source device for a projector provided with a light source. The phosphor unit used in the light source device for a projector has, for example, a phosphor layer including the rare earth aluminate phosphor. The phosphor unit may include a reflective film, a substrate, and an adhesive layer in addition to the phosphor layer containing the rare earth aluminate phosphor. The phosphor unit may have a phosphor layer on a wheel substrate rotatably supported by a motor. It is preferable that the light source used for the light source device for projectors is a semiconductor laser.

  The projector using the light source device for a projector is configured to use a color separation optical system including a dichroic mirror, a reflection mirror, a relay lens, and the like for mixing white colored light emitted from the light source device for the projector. The light components and the blue light components are separated, and the separated light components of each color are made incident on the image forming area of the liquid crystal panel for each color, and the incident color light is modulated according to the image information to form color image light.

  Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples.

Examples 1-1 to 1-3 Preparation step of raw material mixture Yttrium oxide (Y ₂ O ₃ ), cerium oxide (CeO ₂ ), aluminum oxide (Al ₂ O ₃ ), gallium oxide (Ga ₂ O ₃ ) It adjusted and adjusted so that it might become the preparation composition shown to 1. In the feed composition, the raw materials were adjusted so that the molar ratio of Ce was the product of variable n and 3, and variable n was 0.003, 0.008, and 0.015, respectively. Barium fluoride (BaF ₂ ) was added as a flux to each of the adjusted raw materials, and each raw material and the flux were mixed in a ball mill to obtain a first raw material mixture. The content of BaF ₂ in the first raw material mixture is 2.5% by mass with respect to 100% by mass of the first raw material mixture.

First Firing Step The obtained first raw material mixture was put into an alumina crucible and fired at 1500 ° C. for 10 hours in a reducing atmosphere to obtain a first fired product.

Second firing step The obtained first fired product and a second raw material mixture to which barium fluoride (BaF ₂ ) is added as a flux, which is adjusted to have the same feed composition as the feed composition, are subjected to first firing. And the second raw material mixture are mixed in equal proportions such that the mass ratio is 1: 1, and this mixture is put into an alumina crucible and fired at 1500 ° C. for 10 hours in the same reducing atmosphere as the first firing step. A second fired product was obtained. This second firing step was repeated twice. In the second baking step, equal amounts of the second baking product and the second raw material mixture are mixed so that the mass ratio is 1: 1, and the second baking step is performed for the second baking. I got a thing. The fired product obtained in the first second firing step is also a second fired product, and the fired product obtained in the second second firing step is also a second fired product.

Dispersion Treatment Step A second calcined product obtained by repeating the second calcination step twice, alumina balls as a dispersion medium, and pure water were put in a container and dispersed for 30 hours while rotating. Thereafter, coarse particles were removed by wet sieving. Then, sedimentation classification was performed to remove microparticles.

Acid washing treatment step The second baked product obtained by sedimentation classification is acid washed with a hydrochloric acid aqueous solution having a concentration of hydrochloric acid of 17% by mass, then washed with water, separated and dried, and the second baked product after acid washing treatment is carried out It was obtained as the rare earth aluminate phosphor of Examples 1-1 to 1-3.

Comparative Examples 1-1 to 1-3
Preparation step of raw material mixture Yttrium oxide (Y ₂ O ₃ ), cerium oxide (CeO ₂ ), aluminum oxide (Al ₂ O ₃ ), gallium oxide (Ga ₂ O ₃ ) so as to obtain the feed composition shown in Table 1 Adjusted and weighed. In the preparation composition, when the molar ratio of Ce is represented by the product of variable n and 3, the raw materials were adjusted such that variable n was 0.005, 0.01, and 0.017, respectively. Barium fluoride (BaF ₂ ) was added as a flux to each of the adjusted raw materials, and each raw material and the flux were mixed in a ball mill to obtain a first raw material mixture. The content of BaF ₂ in the first raw material mixture is 2.5% by mass with respect to 100% by mass of the first raw material mixture.

Firing Step The obtained first raw material mixture was put into an alumina crucible and fired at 1500 ° C. for 10 hours in a reducing atmosphere to obtain a first fired product.

Dispersion Treatment Step The obtained first baked product, alumina balls as a dispersion medium, and pure water were placed in a container and dispersed for 6 hours while rotating. Thereafter, coarse particles were removed by wet sieving. Then, sedimentation classification was performed to remove microparticles.

Acid washing treatment step The first baked product obtained by sedimentation classification is acid washed with a hydrochloric acid aqueous solution having a concentration of hydrochloric acid of 17% by mass, then washed with water, separated and dried, and the first baked product after acid washing treatment is compared It was obtained as the rare earth aluminate phosphor of Examples 1-1 to 1-3.

Average particle size For baked matter, use a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific), measure a sample of 1 cm ³ min under the environment of temperature 25 ° C. and humidity 70% RH, and use a dedicated tubular container After packing to a dry air at a constant pressure, the specific surface area was read from the differential pressure, and the average particle size was calculated by the FSSS method. The results are shown in Table 1.

Compositional Analysis The obtained phosphors were treated with ICP-AES (Inductively coupled plasma emission analyzer) (product name: Perkin Elmer (Perkin Elmer)) to form each of the elements (Y, Ce) constituting the rare earth aluminate phosphor. The mass percentage (mass%) of Al, Ga, O) was measured, and the molar ratio of each element was calculated from the value of the mass percentage of each element. The molar ratio of Y, Ce, Al, Ga, and O shown in Table 1 is a value calculated based on 3, which is the molar ratio of the total of Y and Ce. The value obtained by dividing the molar ratio of Ce by the molar ratio of the total of Y and Ce is 3 as a variable n. The value obtained by dividing the molar ratio of Ga by the product of the molar ratio 5 of the sum of Al and Ga and the variable k is defined as a variable m. The variable k is a coefficient of 5, and the product of the variables k and 5 is the molar ratio of the sum of Al and the element M1. The variables n, m and k are listed in Table 1. Also, calculated values calculated by applying the variable n to the equation of 1590 n + 531 are shown in Table 1. FIG. 1 shows the light emission peak wavelength λp and the variable n obtained by dividing the molar ratio of Ce in the composition of the rare earth aluminate phosphor according to Examples 1-1 to 1-3 by the molar ratio 3 of the total of Y and Ce. The graph which plotted the relationship and the variable n which divided the molar ratio of Ce in the composition of the rare earth aluminate phosphor according to Comparative Examples 1-1 to 1-3 by the molar ratio 3 of the total of Y and Ce, and the emission peak wavelength It is the graph which plotted the relationship with (nm).

Luminescent Peak Wavelength A rare earth aluminate phosphor according to Examples 1-1 to 1-3, and a rare earth aluminate phosphor according to Comparative Examples 1-1 to 1-3, a quantum efficiency measurement device (manufactured by Otsuka Electronics Co., Ltd.) Each phosphor is irradiated with light with an excitation wavelength of 450 nm using QE-2000), the emission spectrum at room temperature (25 ° C. ± 5 ° C.) is measured, and the wavelength at which the emission spectrum is maximum is the emission peak wavelength (nm) It measured as). The results are shown in Table 1.

Light emission intensity (%)
With respect to the sample containing the rare earth aluminate phosphor according to Example 1-2 and the rare earth aluminate phosphor according to Comparative Example 1-2, a laser beam having a wavelength of 455 nm from the laser diode and a spot diameter of 2.29 The sample was irradiated at 2.53 mm ² , light emitted from the sample was detected by a photodiode through a cut filter, and the light emission intensity of the sample containing each of the rare earth aluminate phosphors was measured by a photodiode monitor unit. The results are shown in FIG.

SEM Image The rare earth aluminate phosphor according to Example 1-2 and the rare earth aluminate phosphor according to Comparative Example 1-2 are embedded in an epoxy resin so that the cross section of the rare earth aluminate phosphor appears The surface is polished with a sandpaper, the surface is finished with a cross section polisher (CP), and a cross section SEM image of each rare earth aluminate phosphor using a scanning electron microscope (SEM) I got FIG. 3 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Example 1-2, and FIG. 4 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Comparative Example 1-2. is there.

  As shown in Table 1, the rare earth aluminate phosphors of Examples 1-1 to 1-3 have a molar ratio of Ce in the composition of these rare earth aluminate phosphors to a molar ratio of the sum of Ce and Y 3 The variable n divided by was 0.003 or more and 0.017 or less, and the emission peak wavelength λp was larger than the calculated value calculated by substituting the variable n into the equation of 1590 n + 531. That is, in the rare earth aluminate phosphors of Examples 1-1 to 1-3, the variable n and the emission peak wavelength λp (nm) of the phosphor at 450 nm satisfy the relational expression λp ≧ 1590n + 531.

  On the other hand, in the rare earth aluminate phosphors of Comparative Examples 1-1 to 1-3, the variable n was obtained by dividing the molar ratio of Ce in the composition of these rare earth aluminate phosphors by the molar ratio 3 of the total of Ce and Y. Although the range of 0.003 or more and 0.017 or less is satisfied, the emission peak wavelength λp is smaller than the calculated value calculated by substituting the variable n into the equation of 1590 n + 531. That is, in the rare earth aluminate phosphors of Comparative Examples 1-1 to 1-3, the relationship between the variable n and the emission peak wavelength λp (nm) of the phosphor at 450 nm is λp <1590n + 531, and the relationship The equation λp ≧ 1590 n + 531 was not satisfied.

  FIG. 1 shows a variable n obtained by dividing the molar ratio of Ce in the composition of the rare earth aluminate phosphor according to Examples 1-1 to 1-3 by the molar ratio 3 of the total of Ce and Y and the respective rare earth aluminate fluorescence The molar ratio of Ce in the composition of the rare earth aluminate phosphor according to Comparative Examples 1-1 to 1-3 is a graph in which the relationship between the emission peak wavelength λp of the body is plotted and the molar ratio of the sum of Ce and Y is 3 It is the graph which plotted the relationship between the variable n remove | divided and the emission peak wavelength (nm) of each rare earth aluminate fluorescent substance. As shown in FIG. 1, even if the emission peak wavelength λp of each phosphor at 450 nm is the same as 537 nm, 544 nm, and 555 nm, the rare earth aluminate according to the example is better than the rare earth aluminate phosphor according to the comparative example. The salt phosphor has a smaller molar ratio of Ce in the composition. Therefore, the saturation luminance can be improved by reducing the molar ratio of Ce. Even when the molar ratio of Ce in the composition of the phosphor is smaller than the molar ratio of Ce in the rare earth aluminate phosphor of the comparative example, the rare earth aluminate phosphor of the example has a short emission peak wavelength. There is no

  FIG. 2 relates to the rare earth aluminate phosphor according to Example 1-2 and the rare earth aluminate phosphor according to Comparative Example 1-2, and the output (LD output) of laser light irradiated to the phosphor and each fluorescence It is a graph which shows a relation with luminescence intensity of a body. As shown in FIG. 2, compared with the rare earth aluminate phosphor according to Comparative Example 1-2, the rare earth aluminate phosphor according to Example 1-2 has a light emission intensity relative to the laser output irradiated to the phosphor. Has a high degree of linearity and high saturation brightness.

  FIG. 3 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Example 1-2. As shown in FIG. 3, in the rare earth aluminate phosphor according to Example 1-2, the first baked product obtained in the first baking step serves as a core, and the second baking step performed twice performs the first baking. Two layers of fired products are formed around the core of the product. As shown in the SEM photograph of FIG. 3, the rare earth aluminate phosphor according to Example 1-2 has three layers of a core, a first layer, and a second layer in a cross-sectional view of phosphor particles, The boundaries of each layer were darker in color. As shown in the SEM photograph of FIG. 3, in the rare earth aluminate phosphor according to Example 1-2, three layers of the core, the first layer, and the second layer can be distinguished in the cross sectional view of the phosphor particle. Although there are some, it is not possible to confirm large shades of color other than the boundaries between the core, the first layer, and the second layer. From this, it can be inferred that the rare earth aluminate phosphor according to Example 1-2 is homogeneous in all of the core, the first layer, and the second layer.

  FIG. 4 is a SEM photograph showing a cross section of the rare earth aluminate phosphor according to Comparative Example 1-2. As shown in FIG. 4, in the cross section of the rare earth aluminate phosphor according to Comparative Example 1-2, a portion where the color is changed can be confirmed on the SEM photograph, and it is estimated that the portion is not homogeneous.

  A rare earth aluminate phosphor according to one aspect of the present invention or a rare earth aluminate phosphor obtained by a method for producing the same is combined with a light emitting element of LED or LD to produce a light emitting device for automotive or general lighting, liquid crystal display It can be used for the backlight of the device and the light source device for the projector.

Claims (15)

At least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, Ce, Al, and optionally at least one element M1 selected from Ga and Sc,
The molar ratio of the total of the rare earth elements Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is the product of 5 and a variable k of 0.95 to 1.05, and the molar ratio of Ce is , A composition of a rare earth aluminate which is the product of a variable n and a value of 0.003 or more and 0.017 or less,
A rare earth aluminate phosphor characterized in that an emission peak wavelength λ _p (nm) at an excitation wavelength of 450 nm and the variable n satisfy the relation λ _p 151590 n + 531. The rare earth aluminate phosphor according to claim 1, wherein the composition is represented by the following formula (I-1).
(Ln _1-n Ce _n ) ₃ (Al _1-m M1 _m ) _{5 k} O ₁₂ (I-1)
(In the formula (I-1), Ln is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd and Tb, and M1 is at least one element selected from Ga and Sc And k, n and m are numbers satisfying 0.95 ≦ k ≦ 1.05, 0.003 ≦ n ≦ 0.017, and 0 ≦ m ≦ 0.02, respectively.)   The rare earth aluminate phosphor according to claim 1 or 2, wherein the Ln contains Y.   The rare earth aluminate phosphor according to any one of claims 1 to 3, wherein the M1 contains Ga.   The rare earth aluminate phosphor according to any one of claims 1 to 4, wherein the average particle size measured by the FSSS method is 15 μm or more.   The rare earth aluminate phosphor according to any one of claims 1 to 5, having a plurality of layers including the composition in a cross sectional view of the rare earth aluminate phosphor particles.   A light source device for a projector, comprising: a phosphor unit having the rare earth aluminate phosphor according to any one of claims 1 to 6; and a light source.   The light source device for a projector according to claim 7, wherein the light source is a semiconductor laser.   A projector using the light source device according to claim 7. A compound containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound containing Ce, a compound containing Al, and optionally at least one selected from Ga and Sc In the compound containing the element M1, the molar ratio of the total of the rare earth element Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is 5, and the molar ratio of Ce is 0.003 or more. A first firing step to obtain a first fired product by firing the first raw material mixture prepared by adjusting the feed composition and mixing so as to be a product of a variable n and a value of 017 or less;
A compound containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd and Tb, a compound containing Ce, a compound containing Al, and optionally Ga and In the compound containing at least one element M1 selected from Sc, the molar ratio of the total of the rare earth elements Ln and Ce is 3, the molar ratio of the total of Al and the element M1 is 5, and the molar ratio of Ce The mixture containing the second raw material mixture prepared by adjusting the feed composition and mixing so that the product of the variable n and the variable n becomes 0.003 or more and 0.017 or less becomes a second baked product A method for producing a rare earth aluminate phosphor, comprising at least one step.   The method for producing a rare earth aluminate phosphor according to claim 10, comprising the step of acid-washing the first fired product and / or the second fired product.   The first raw material mixture in the first baking step and / or the second raw material mixture in the second baking step contain at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Mn as a flux. The manufacturing method of the rare earth aluminate fluorescent substance of Claim 10 or 11 which contains 0.5 to 10 mass% of the compound to contain.   The baking temperature in a said 1st baking process and / or a said 2nd baking process is 1400 degreeC or more and 1800 degrees C or less, The baking time is 5 hours or more and 20 hours or less, Any one of Claim 10 to 12 Of producing rare earth aluminate phosphors.   The method for producing a rare earth aluminate phosphor according to any one of claims 10 to 13, wherein an atmosphere in the first firing step and / or the second firing step is a reducing atmosphere. The manufacturing method of the rare earth aluminate phosphor according to any one of claims 10 to 14, wherein the preparation composition is represented by the following formula (I-2).
(Ln _1-n Ce _n ) ₃ (Al _1-m M _{1 m} ) ₅ O ₁₂ (I-2)
(Wherein, L n is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd and Tb, and M 1 is at least one element selected from Ga and Sc) And n and m are numbers satisfying 0.003 ≦ n ≦ 0.017 and 0 ≦ m ≦ 0.02, respectively.)