JP2012214592A - Method for producing silicate fluorophor, and fluorophor formed by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing strontium silicate-based fluorophor for a white LED in which the phase purity is ≥90 wt.%.SOLUTION: The method for producing the fluorophor to be expressed by the composition formula 1: (SrMEu)SiO(where, 0.001≤x≤0.1, and 0≤y≤0.2, and M represents a bivalent metal.) includes at least three steps, i.e. a step 1 in which a fluorophor raw material is subjected to the wet mixing, an aggregated mixture obtained by drying and removing its solvent is cracked, and a calcination product is produced by the heat treatment in the first stage at temperatures of 1,150-1,250°C under an air atmosphere, and successively, by the heat treatment in the second stage at temperatures of 1,450-1,550°C under an air atmosphere; a step 2 of a classifying step in which the calcinated product is subjected to dry grinding, and only the particles of the particle size of 32-100 μm are taken out; and a step 3 of a heat treatment step in which the powder consisting of taken-out particles is subjected to heat treatment at temperatures of 1,450-1,550°C for 1-10 hours in an inert gas flow containing Hby 2-12 vol.% in a weakly reducing atmosphere.

Description

The present invention relates to a method for producing Eu2 ⁺ -activated strontium silicate phosphors that exhibit high-luminance orange light emission by photoexcitation in the ultraviolet to visible range.

The white LED is generally composed of a blue LED and a yellow phosphor. Up to now, it has been actively developed as an LCD backlight light source for small devices, but as a next-generation application, lighting applications are cited. Existing phosphors for white LEDs include YAG: Ce ³⁺ that exhibits yellow fluorescence by blue excitation, (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺ , Sr ₃ SiO ₅ that exhibits green to yellow fluorescence: Eu ²⁺ (in terms of composition formula, (Sr _1-x Eu _x ) ₃ SiO ₅ ) is known, and a phosphor with higher luminance is desired.

In order to produce a phosphor using Ce ³⁺ , Eu ²⁺ , or Tb ³⁺ with unstable valence as an activator, heat treatment is generally performed in a weakly reducing atmosphere with an inert gas containing several percent of H _2. It is. However, when manufacturing a strontium silicate phosphor, Eu ³⁺ is not reduced and does not become Eu ²⁺ by heat treatment in the air or in an oxidizing atmosphere, so that substitution to Sr ²⁺ sites does not occur, and an inert atmosphere It is known that Eu ²⁺ is not sufficiently replaced with Sr ²⁺ sites even in the heat treatment below, and a high-luminance phosphor cannot be obtained.

For example, Patent Document 1 describes that after mixing raw materials, heat treatment is performed in a reducing atmosphere of N ₂ to which 5% H ₂ is added at 1100 to 1400 ° C. for 3 to 5 hours. Patent Document 2 also describes that the raw material mixture is heat-treated in a reducing atmosphere. In Patent Document 3, it is described that a raw material is used as a precursor obtained by wet reaction, and is heat-treated in a reducing atmosphere.

However, as described in the above-mentioned patent document, when heat treatment is performed in one step in a reducing atmosphere, during the heat treatment in the reducing atmosphere, decomposition of raw materials, solid phase reaction of SrO and SiO ₂ , Eu ²⁺ Sr ²⁺ site Since the reaction is made nonuniform and the reaction becomes non-uniform, there is a problem that an impurity phase is easily generated.

On the other hand, since the obtained phosphor is coarsened or sintered by heat treatment, pulverization is generally performed to obtain a phosphor having a predetermined particle size.
However, it is known that when the phosphor is pulverized, defects in the crystal increase and luminance decreases (see Non-Patent Document 1).

As a method of improving the coarse particle size and reaction nonuniformity of the phosphor, a method of performing the heat treatment twice or more has been proposed (see Patent Document 4).
For example, a method is shown in which a hydrate precursor is synthesized by wet synthesis, followed by spray heat treatment in the air, and then heat treatment in a reducing atmosphere. However, in this method, it is considered that a phosphor crystal is formed by a solid-phase reaction occurring in a heat treatment in a reducing atmosphere, and it is assumed that the size of the particles is not small.

Moreover, in order to perform reaction more uniformly, after removing the organic substance by the heat processing in air | atmosphere, the method of sintering under reducing atmosphere is shown (refer patent document 5).
Also in this method, since the heat treatment temperature in the atmosphere is about several hundreds of degrees Celsius (for example, 500 ° C.), it is estimated that the formation of the phosphor crystal occurs during the heat treatment in a reducing atmosphere.

JP 2006-36943 A JP-T-2006-514152 JP 2007-131843 A JP 2003-206480 A Japanese Patent No. 4185162

Development of the latest LED materials Technical Information Association (2007) p. 178

  An object of the present invention is to provide a method for producing a high-intensity strontium silicate phosphor by optimizing heat treatment conditions in a method for producing a phosphor for white LED. Another object of the present invention is to provide a phosphor having a strontium silicate phosphor having a phase purity of 90 wt% or more as determined by Rietveld analysis of X-ray diffraction.

In order to solve such a problem, the present inventors have conducted extensive research, and as a result, by heat-treating the raw material mixture in the atmosphere at a predetermined two-stage temperature in advance, the phase purity of Sr ₃ SiO ₅ is increased. Found that you can. Furthermore, the obtained calcined product is pulverized, classified to a predetermined particle size, and then the phosphor obtained by heat treatment in a weakly reducing atmosphere is not sintered, so there is no need for crushing and there are no crystal defects. It has been found that it does not occur and is a phosphor having a predetermined particle size because the calcined material is classified before heat treatment.
Therefore, the strontium silicate phosphor obtained through the above steps has high phase purity of Sr ₃ SiO ₅ , few crystal defects, and a predetermined particle size, and therefore has higher brightness than before. It came to the headline and this invention.

The first invention of the present invention is a composition formula 1 “(Sr _{1- xy My} Eu _x ) ₃ SiO ₅ (where 0.001 ≦ x ≦ 0.1, 0 ≦ y ≦ 0.2, In the method for producing a phosphor represented by “M is a divalent metal)”, the phosphor is produced through at least the following three steps.
Step 1: The phosphor raw material is weighed so as to have the composition represented by the composition formula 1, and after performing wet mixing using a solvent, the solvent is dried and removed, and the resulting agglomerated mixture is crushed and then in the atmosphere. , Heat treatment at 1150 to 1250 ° C., followed by heat treatment at 1450 to 1550 ° C. in the air to obtain a calcined product.
Step 2: A step of taking out the particles having a particle size of 32 to 100 μm by dry pulverization and classification of the calcined product obtained in Step 1.
Step 3: a powder consisting of taking out particles, as the weak reducing atmosphere, an inert gas flow in the addition of 2～12Vol% of _{H 2} gas, at a temperature of 1450-1550 ° C., a heat treatment of 10 hours Process.

In the second invention of the present invention, the metal represented by M in the composition formula 1 “(Sr _{1- xy My} Eu _x ) ₃ SiO ₅ ” in the first invention is selected from alkaline earth metals. It is a method for producing a phosphor, which is made of one or more kinds of metals.

  A third invention of the present invention is a phosphor characterized in that the phase purity of the phosphor according to the first or second invention is 90 wt% or more as a quantitative value of X-ray diffraction by Rietveld analysis. is there.

According to the present invention, the particle size is 32 to 100 μm, the phase purity represented by the composition formula 1 of “(Sr _{1- xy My} Eu _x ) ₃ SiO ₅ ” is as high as 90 wt% or more, and high brightness. The phosphor for white LED can be manufactured and obtained, and has an industrially remarkable effect.

It is a figure which shows the excitation spectrum and emission spectrum of the fluorescent substance sample produced in Example 1 of this invention.

Hereinafter, the phosphor manufacturing process in the embodiment of the present invention will be described.
[Step 1]
In step 1, compounds such as carbonates, nitrates, oxalates and hydroxides can be used as raw materials for each element.
As for Sr, a carbonate which is inexpensive and relatively low in toxicity is desirable, and it is desirable to use an oxide which is inexpensive and less harmful as a raw material for Eu and Si. Here, the addition amount x of Eu as an activator is preferably in the range of 0.001 ≦ x ≦ 0.1.

If Eu is not added, the phosphor does not emit light, and if the addition amount increases, the emission intensity decreases due to concentration quenching. In order to change the emission color of the phosphor, a part of Sr may be replaced with another element.
The element to be replaced may be a divalent metal, preferably an alkaline earth metal, and more preferably Ba, Ca, or Mg. Moreover, not only one type of element to be replaced but two or more types may be combined.
As for the element amount, it is desirable that y is 0.2 or less. If the amount exceeds this, the emission intensity decreases, which is not preferable.

These raw materials are weighed in a stoichiometric ratio so as to have the composition represented by the composition formula 1, and wet mixed using a solvent.
As a solvent, it is required that each raw material does not dissolve and that it is easy to remove by evaporation at a relatively low temperature. Alcohols such as methanol, ethanol, propanol, butanol, acetone, methyl ethyl ketone, etc. Ketones, ethers such as diethyl ether and tetrahydrofuran, and esters such as ethyl acetate and butyl acetate can be used. However, the present invention is not limited to these, and a mixture of two or more types may be used. .
Among these, it is preferable to use ethanol as a low harmful solvent.

For removing the solvent from the mixture, drying is performed at 80 to 200 ° C. using an oven or the like. Since the obtained dried product is agglomerated, it is crushed using a mortar.
The pulverized dry matter is put in an alumina container, placed in an electric furnace, heat-treated at 1150 to 1250 ° C. in the air, and subsequently heat-treated at a temperature of 1450 to 1550 ° C. in the air. can get. Note that after heat treatment at 1150 to 1250 ° C., the temperature may be lowered once, and then heat treatment may be performed again at 1450 to 1550 ° C. In addition, in order to promote sintering and crystallization of the calcined product, flux (for example, Mg, Ca, Sr, Ba, Zn fluorides, chlorides, bromides, iodides and other halides) may be added.
Here, in the obtained calcined product, in addition to the case of using SrCO ₃ as a raw material, when a compound containing an organic functional group is used, CO ₂ generated by thermal decomposition of the organic functional group during the heat treatment. Are obtained from SrCO ₃ produced by reacting with a raw material strontium compound.

The first stage of the heat treatment in the air is aimed at decomposing SrCO ₃ and the second stage is aimed at forming a Sr ₃ SiO ₅ crystal phase.
Therefore, when the temperature at the first stage is lower than 1150 ° C., decomposition of SrCO ₃ is not promoted, and SrCO ₃ remains even after heat treatment at 1450 to 1550 ° C. Therefore, SrSiO ₃ which is a different phase of Sr ₃ SiO _{5 This} is not preferable because _three phases are generated. Further, the crystallization of _Sr 3 SiO ₅ starts while the SrCO ₃ higher than 1250 ° C. is not _degraded, to such SrSiO _3-phase a secondary phase Sr 3 SiO ₅ is produced, also not preferable.

On the other hand, the temperature of the second stage heat treatment is lower than 1450 ° _C., Sr 3 purity of _Sr 3 SiO ₅ crystal phase for solid-phase reaction to SiO ₅ is not accelerated is _lowered, Sr 2 SiO ₄ or SrSiO _3, also Since Sr (OH) ₂ due to unreacted SrO remains as a different phase, it is not preferable. When the heat treatment temperature is higher than 1550 ° C., the Sr ₃ SiO ₅ crystal is melted, which is not preferable because it adheres to a container or the like and the yield decreases.

The purity of the Sr ₃ SiO ₅ crystal phase obtained by the atmospheric heat treatment performed in these two steps is quantified by X-ray diffraction by Rietveld analysis.
In this Rietveld analysis method, the diffraction pattern calculated based on the approximate structure model is applied to the measured diffraction pattern, the crystal structure parameters and the lattice constant are refined, and the mass ratio of multiple crystal phases can be obtained semi-quantitatively. .

The purity of the Sr ₃ SiO ₅ crystal phase of the calcined product after heat treatment in the air is desirably 90 wt% or more, more desirably 95 wt% or more, and even more desirably 98 wt% or more.
Note that, by heat treating the calcined product in a weak reducing atmosphere, Eu ²⁺ is dissolved in the Sr ²⁺ site, so that the phase purity of the calcined product is the same as the phase purity of the phosphor. Even if a part of Sr is replaced with another element, there is no problem as long as the Sr ₃ SiO ₅ crystal phase is not destroyed.

[Step 2]
Next, in step 2, the calcined material produced in step 1 is dry-pulverized.
In the dry pulverization, it is desirable to carry out by a method with little damage to the particles such as mortar pulverization in order to avoid excessive breakage and damage in the crystal particles.

Next, the pulverized powder is classified to a particle size of 32 to 100 μm using a vibration sieve. As this classification method, as long as the method does not damage the particles, other airflow classification may be used. The particle size of the particles obtained by classification is preferably 32 to 100 μm.
A particle size of less than 32 μm is not preferable because damage due to pulverization is large and the ratio of surface defects to the particles increases, resulting in low luminance. On the contrary, when the particle diameter is larger than 100 μm, there is no great difference in luminance, but it is not preferable because it is immediately settled when dispersed in a resin when applied to an LED.

[Step 3]
In step 3, the powder particles of the calcined product classified and taken out in step 2 are placed in a Mo container and placed in an electric furnace. When a general alumina or Pt container is used, it reacts at the interface with the powder sample of the calcined product, and a high-luminance phosphor cannot be obtained. Therefore, examples of suitable materials for containers that have high heat resistance, can withstand weakly reducing atmospheres, and do not react with powder samples include W and Mo. It is good to use.

As the weak reducing atmosphere to be used, _{2 to} 12 vol% of H ₂ gas is used as the weak reducing atmosphere, added to the inert gas, and the inert gas containing the weak reducing atmosphere is allowed to flow, and 1450 to 1550 ° C. The heat treatment is performed at the temperature.
If the H ₂ gas concentration is too high or too low, a high-luminance phosphor cannot be obtained. If the hydrogen concentration is too high, the Sr ₃ SiO ₅ crystal itself is reduced and colored, resulting in low luminance. Conversely, if the hydrogen concentration is too low, Eu ³⁺ is not sufficiently reduced, and Sr ²⁺ Since the substitution to the site does not occur sufficiently, a phosphor with high brightness cannot be obtained.

When the heat treatment temperature is lower than 1450 ° C., Eu ³⁺ as an activator is not sufficiently reduced, and substitution to Sr ²⁺ sites does not occur sufficiently, so that a high-luminance phosphor cannot be obtained. On the other hand, if the heat treatment temperature is higher than 1550 ° C., the sample melts and does not become phosphor powder.

Furthermore, the heat treatment time is performed for 1 to 10 hours. When the time is shorter than 1 hour, Eu ²⁺ is not sufficiently replaced with the Sr ²⁺ site, and a high-luminance phosphor cannot be obtained. On the other hand, if the heat treatment time is longer than 10 hours, sintering proceeds and the sample adheres to the container, resulting in poor recovery. Further, the particles are bonded to each other, and the effect of pulverization and classification in step 2 is lost. Therefore, the heat treatment time is preferably about 3 hours. If it is desired to perform heat treatment for a longer time, it is preferable to cool the furnace once and then perform the heat treatment again. Note that since the solid-phase reaction is sufficiently completed in Step 1, the particles do not become coarse even if the heat treatment is repeated.

By the above three steps, the Sr ₃ SiO ₅ crystal phase has a high purity and is not pulverized after the final heat treatment, so that it is not damaged by pulverization and has a particle size of 32 to 100 μm. Can be manufactured.

  Next, the phosphor manufacturing method of the present invention will be described in more detail using an example which is an example of the above embodiment.

116.7 g of SrCO ₃ , 2.1 g of Eu ₂ O ₃ and 16.1 g of SiO ₂ (weighed so that “(Sr _0.985 Eu _0.015 ) ₃ SiO ₅ )” in composition formula 1) The mixture was wet mixed with ethanol for 2 hours, dried in an oven at 120 ° C. for 2 hours, and then crushed in a mortar.
The obtained dry powder is put in an alumina crucible and placed in an electric furnace, and in the air, the first stage heat treatment is performed at 1200 ° C. for 3 hours, followed by the second stage heat treatment at 1500 ° C. for 3 hours. A calcined product was produced.
The prepared calcined product is pulverized in an alumina mortar, classified with a sieve having an opening of 32 μm and 100 μm, and the powder in the range of 32 to 100 μm is placed in a Mo container and placed in an electric furnace, and is placed at 1500 ° C. 3 A phosphor sample was formed by heat-treating in a weakly reducing atmosphere while flowing Ar gas containing 4 vol% of hydrogen gas (H ₂ ) for a time.

As for the phase purity of the calcined product, the diffraction pattern of the calcined product is measured using an X-ray diffractometer (Spectres, X'Pert-PRO / MPD), and the phase purity of Sr ₃ SiO ₅ is determined by Rietveld analysis. Asked.
The results are shown in Table 1.

About the obtained fluorescent substance sample, the emission spectrum in excitation wavelength 455nm was measured using the fluorescence spectrophotometer (the JASCO make, FP-6500), and the peak area was made into YAG: Ce (Phosphor Technology Ltd., model number. QMK58) was determined as the PL relative intensity.
The results are shown in Table 1. In addition, if PL relative intensity | strength was 1.5 times or more of YAG: Ce, it determined with high brightness | luminance.

FIG. 1 also shows the excitation spectrum and emission spectrum of the phosphor sample obtained. The excitation spectrum is normalized with a value at an excitation wavelength of 455 nm. The emission spectrum is normalized by the value of the maximum peak wavelength.
From FIG. 1, it can be seen that a wide range of excitation and absorption from the ultraviolet region to the blue region is observed, and a phosphor applicable to a white LED that exhibits orange light emission with an emission wavelength of 584 nm can be manufactured.

  In addition, as a reference example, each characteristic when the classification condition of the sample produced in Example 1 is larger than 100 μm (Reference Example 1) and less than 32 μm (Reference Example 2) is shown in Table 1.

A phosphor sample was prepared in the same manner as in Example 1 except that 138.8 g of strontium oxalate (SrC ₂ O ₄ ) was used as the Sr raw material instead of SrCO ₃ . Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the first stage baking temperature was 1150 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was produced in the same manner as in Example 1 except that the first stage baking temperature was 1250 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the second stage baking temperature was 1450 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the second stage baking temperature was 1550 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the temperature of the weak reducing atmosphere heat treatment was changed to 1450 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the temperature of the weak reducing atmosphere heat treatment was changed to 1550 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the hydrogen concentration in the Ar gas during the heat treatment in the weak reducing atmosphere was changed to 2 vol%. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the hydrogen concentration in the Ar gas during the heat treatment in the weak reducing atmosphere was changed to 12 vol%. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment time for the weak reducing atmosphere was changed to 1 hour. Table 1 shows the evaluation results of the obtained phosphor sample.

  A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment time for the weak reducing atmosphere was 10 hours. Table 1 shows the evaluation results of the obtained phosphor sample.

97.3 g of SrCO ₃ , 19.4 g of BaCO ₃ , 1.3 g of Eu ₂ O ₃ , and 15.3 g of SiO ₂ (in the composition formula 1, “(Sr _0.86 Ba _0.13 Eu _0.01 )” ₃ SiO ₅ ) ”. Thereafter, the same process as in Example 1 was performed to prepare a phosphor sample. By adding Ba, a phosphor exhibiting deep orange emission with an emission wavelength of 602 nm at an excitation wavelength of 455 nm was obtained. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 1)
A two-stage heat treatment was performed in the atmosphere under the same formulation and conditions as in Example 1 to obtain a calcined product. The obtained calcined product was directly heat-treated in a weakly reducing atmosphere under the same conditions as in Example 1 without classification, and the obtained powder was pulverized in a mortar to produce a phosphor sample. The evaluation results of the phosphor sample are shown in Table 1.

(Comparative Example 2)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment temperature in the first step was set to 1100 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 3)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment temperature in the first step was set to 1300 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 4)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment temperature in the second step was 1400 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 5)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment temperature in the second stage was 1600 ° C. In Comparative Example 5, the sample melted and fixed after heat treatment at 1600 ° C. in the atmosphere, and a phosphor sample was not obtained.

(Comparative Example 6)
A phosphor sample was prepared in the same manner as in Example 1 except that the temperature of the heat treatment in the weak reducing atmosphere was 1400 ° C. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 7)
A phosphor sample was produced in the same manner as in Example 1 except that the temperature of the weakly reducing atmosphere heat treatment was changed to 1580 ° C. In Comparative Example 7, the sample melted after heat treatment at 1580 ° C. in a weak reducing atmosphere, and a phosphor sample could not be obtained.

(Comparative Example 8)
A phosphor sample was prepared in the same manner as in Example 1 except that the hydrogen concentration in the Ar gas during the heat treatment in the weak reducing atmosphere was 1 vol%. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 9)
A phosphor sample was prepared in the same manner as in Example 1 except that the hydrogen concentration in the Ar gas during the heat treatment in the weak reducing atmosphere was 16 vol%. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 10)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment time of the weakly reducing atmosphere heat treatment was changed to 0.5 hour. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 11)
A phosphor sample was prepared in the same manner as in Example 1 except that the heat treatment time of the weak reducing atmosphere heat treatment was 12 hours. However, after 12 hours of the weak reducing atmosphere heat treatment, the sample adhered to the container. The phosphor sample according to Comparative Example 11 was not obtained.

(Comparative Example 12)
Wet mixing and drying were performed under the same formulation and conditions as in Example 1 to obtain a dry powder. The obtained dry powder was heat-treated at 1500 ° C. for 3 hours in a weakly reducing atmosphere while flowing Ar gas containing 4 vol% of H ₂ to obtain a phosphor sample. Table 1 shows the evaluation results of the obtained phosphor sample.

(Comparative Example 13)
Wet mixing and drying were performed under the same formulation and conditions as in Example 1 to obtain a dry powder. The obtained dry powder was heat-treated at 1500 ° C. in the air to obtain a dry powder. The obtained dry powder was heat-treated at 1500 ° C. for 3 hours in a weakly reducing atmosphere while flowing Ar gas containing 4 vol% of H ₂ to obtain a phosphor sample. Table 1 shows the evaluation results of the obtained phosphor sample.

Claims (3)

In composition formula 1 “(Sr _{1- xy My} Eu _x ) ₃ SiO ₅ (where 0.001 ≦ x ≦ 0.1, 0 ≦ y ≦ 0.2, M is a divalent metal)” In the method for producing the phosphor shown,
It is manufactured through at least the following three steps.
Step 1: The phosphor raw material weighed so as to have the composition represented by composition formula 1 is wet-mixed using a solvent, and then the solvent is dried and removed, and the resulting agglomerated mixture is crushed, A step of performing a first heat treatment at a temperature of 1150 to 1250 ° C., and subsequently performing a second heat treatment at a temperature of 1450 to 1550 ° C. in the air to obtain a calcined product.
Step 2: A step of dry pulverizing the calcined product obtained in Step 1 and then classifying it to take out only particles having a particle size of 32 to 100 μm.
Process 3: Heat treatment at a temperature of 1450 to 1550 ° C. for 1 to 10 hours in an inert gas flow containing ₂ to 12 vol% of H ₂ gas as a weakly reducing atmosphere for the powder composed of the particles taken out in the process 2 Process. The metal represented by M in the composition formula 1 “(Sr _{1- xy My} Eu _x ) ₃ SiO ₅ ” is one or more metals selected from alkaline earth metals. A method for producing the phosphor according to 1.   The phosphor formed using the production method according to claim 1 or 2, wherein the phase purity of the phosphor is 90 wt% or more as a quantitative value of X-ray diffraction by Rietveld analysis.

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