JP2018070431A - Light-wavelength conversion member and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-wavelength conversion member and a light-emitting device that can have both high fluorescence intensity and high color homogeneity.SOLUTION: A light-emitting device 1 is provided with a housing 3, a light-emitting device 5, and light-wavelength conversion member 9. The light-wavelength conversion member 9 comprises a ceramic sintered body as a polycrystalline material in which a crystal particle AlOand a crystal particle having a component represented by chemical formula ABO:Ce are included as main components. More particularly, A and B each in ABOis at least one element selected from the element group below. The at least one element selected from the element group below is distributed between each crystal particle interior and crystal grain boundaries of the ceramic sintered body, and for the elements distributed at each crystal particle interior and crystal grain boundary, the density at the crystal grain boundary is higher than that in each crystal particle interior. A is Sc, Y, or lanthanoid (excluding Ce); and B is Al or Ga.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical wavelength conversion member capable of converting the wavelength of light and a light emitting device including the optical wavelength conversion member.

  In headlamps and various lighting equipment, devices that obtain white color by converting the wavelength of blue light from light emitting diodes (LEDs) and semiconductor lasers (LDs: Laser Diodes) with phosphors have become mainstream. ing.

  As the phosphor, a resin system or a glass system is known, but in recent years, the output of the light source has been increased, and the phosphor has been required to have higher durability. Attention has been focused on ceramic phosphors.

As this ceramic phosphor, a phosphor in which Ce is activated in a garnet structure (A ₃ B ₅ O ₁₂ ) component typified by Y ₃ Al ₅ O ₁₂ : Ce (YAG: Ce) is known.

For example, Patent Document 1 below discloses a technique in which heat resistance and thermal conductivity are improved by compounding YAG: Ce in Al ₂ O ₃ .

Japanese Patent No. 4609319 Japanese Patent No. 5740017

However, in these prior arts, the inclusion of Al ₂ O ₃ has higher thermal conductivity than the YAG: Ce single composition, and as a result, the heat resistance and laser output resistance are improved. There was a serious problem.

For example, since the technique described in Patent Document 1 produces a sintered body by a unidirectional solidification method, it can only produce a composition having a volume ratio of Al ₂ O ₃ / YAG: Ce = 55/45. In addition, the fluorescence characteristics such as fluorescence intensity and color unevenness (color variation) are limited.

Further, in the technique described in Patent Document 2, CeAl ₁₁ O ₁₈ is precipitated in the crystal in order to prevent color unevenness due to Ce concentration unevenness due to Ce evaporation during firing, but CeAl ₁₁ O ₁₈ itself has fluorescent characteristics. Therefore, the presence of the substance impairs the fluorescence characteristics of the entire sintered body.

  Moreover, none of the prior arts has been able to control even the fine grain boundary, and the fluorescent properties such as fluorescence intensity and color unevenness are inferior to conventional resin-based and glass-based phosphors.

  This invention is made | formed in view of the said subject, The objective is to provide the light wavelength conversion member and light-emitting device which can make high fluorescence intensity and high color homogeneity compatible.

(1) In the first aspect of the present invention, Al ₂ O ₃ crystal particles and crystal particles of a component represented by the chemical formula A ₃ B ₅ O ₁₂ : Ce (hereinafter referred to as A ₃ B ₅ O ₁₂ : Ce crystal particles). And a light wavelength conversion member composed of a ceramic sintered body which is a polycrystal having a main component.

In this optical wavelength conversion member, A and B in A ₃ B ₅ O ₁₂ are at least one element selected from the following element group, and each crystal grain in the ceramic sintered body and grain boundaries And at least one element selected from the following element group is distributed, and the element distributed in each crystal grain and in the grain boundary has a grain boundary concentration higher than that in each crystal grain. high.

A: Sc, Y, lanthanoid (excluding Ce)
B: Al, Ga
Thus, in the light wavelength conversion member of the first aspect, the element distributed in each crystal grain and the crystal grain boundary has a higher concentration at the crystal grain boundary than the concentration within each crystal grain. As is clear from the above, high fluorescence intensity and high color homogeneity (that is, small color variation) can be realized.

  Specifically, in the first aspect, since the specific element described above is distributed more in the crystal grain boundary than in the crystal grain and becomes a supply source of the element, the density unevenness accompanying evaporation during firing (therefore the color) It is considered that (variation) can be reduced. This is apparent from the concentration distribution after firing.

  In addition, the presence of the element at the crystal grain boundary alleviates reflection and refraction (birefringence) that occur at the discontinuous interface such as the crystal grain boundary, and is less likely to cause a decrease in translucency due to excessive grain boundary scattering. Become. Therefore, it is considered that high fluorescence intensity can be obtained.

  Moreover, since the light wavelength conversion member of the first aspect has high thermal conductivity due to the above-described configuration, even when the light source has a high output, it is possible to suppress the influence of heat, for example, light Disappearance can be suppressed.

  Furthermore, since this light wavelength conversion member is a ceramic sintered body, its strength is high, and even when light is repeatedly irradiated from a light source, its performance is not easily deteriorated, and furthermore, weather resistance is also excellent. There is an advantage.

In a second aspect of (2) the present _invention, A ₃ B _{5 O} 12: Ce concentration in the crystal particles of the component represented by Ce is, free of 10.0 mol% or less (0 for the element A ).
When the Ce concentration in the A ₃ B ₅ O ₁₂ : Ce crystal particles is 0 mol% with respect to the element A, it is difficult to obtain sufficient fluorescence intensity. On the other hand, when the Ce concentration is higher than 10 mol%, concentration quenching is likely to occur, which may cause a decrease in fluorescence intensity.

Therefore, as in the second aspect, when the Ce concentration in the A ₃ B ₅ O ₁₂ : Ce crystal is 10 mol% or less (not including 0) with respect to the element A, high fluorescence intensity can be realized. Therefore, it is preferable.

(3) In a third aspect of the present invention, a ceramic _A 3 _B 5 _O 12 occupying the sintered body: the proportion of the crystal grains of the component represented by Ce is a 3~70vol%.
Here, when the amount of A ₃ B ₅ O ₁₂ : Ce crystal particles is less than 3 vol%, the amount of A ₃ B ₅ O ₁₂ : Ce crystal particles is small, so that it may be difficult to obtain sufficient fluorescence intensity. On the other hand, when the amount of A ₃ B ₅ O ₁₂ : Ce crystal particles is more than 70 vol%, grain boundary scattering at the heterogeneous interface, that is, the interface between Al ₂ O ₃ crystal particles and A ₃ B ₅ O ₁₂ : Ce crystal particles increases. , It may be difficult to obtain sufficient translucency (that is, the fluorescence intensity decreases).

Therefore, as in the third aspect, when the A ₃ B ₅ O ₁₂ : Ce crystal particles are 3 to 70 vol%, it is preferable because sufficient translucency can be obtained and the emission intensity can be increased. .
(4) 4th aspect of this invention is a light-emitting device provided with the optical wavelength conversion member in any one of 1st-3rd aspect.

The light whose wavelength is converted by the light emitting device of the fourth aspect (specifically, the light wavelength conversion member) (that is, fluorescence) has high fluorescence intensity and high color homogeneity.
In addition, as a light emitting element of a light-emitting device, well-known elements, such as LED and LD, can be used, for example.

<Each configuration of the present invention will be described below>
The “light wavelength conversion member” is a ceramic sintered body having the above-described configuration, and each crystal particle and its grain boundary may contain inevitable impurities.

The “main component” indicates that the largest amount (volume) exists in the light wavelength conversion member.
-The above "A ₃ B ₅ O ₁₂ : Ce" indicates that Ce is a solid solution substitution in a part of A in A ₃ B ₅ O _12. By having such a structure, The compound exhibits fluorescence characteristics.

  -As said "concentration", the various parameter | index which shows the ratio of content, such as mol%, weight% (wt%), volume% (vol%), can be employ | adopted, for example.

It is sectional drawing which shows the cross section which fractured | ruptured the light-emitting device provided with the light wavelength conversion member in the thickness direction. (A) is a BF-STEM image of the sample of No. 3, (b) is a graph which shows the change of the density | concentration by the line analysis with respect to the sample of (a). (A) is a BF-STEM image of the sample of No. 8, and (b) is a graph showing a change in concentration by line analysis for the sample of (a). (A) is a BF-STEM image of the sample of No. 18, and (b) is a graph showing the change in concentration by line analysis for the sample of (a). (A) is a BF-STEM image of the sample of No. 20, and (b) is a graph showing a change in concentration by line analysis for the sample of (a).

Next, embodiments of the light wavelength conversion member and the light emitting device of the present invention will be described.
[1. Embodiment]
[1-1. Light emitting device]
First, the light-emitting device provided with the light wavelength conversion member will be described.

  As shown in FIG. 1, a light emitting device 1 of the present embodiment includes a box-shaped ceramic package (container) 3 such as alumina, and a light emitting element 5 such as an LD disposed inside the container 3. And a plate-like light wavelength conversion member 9 disposed so as to cover the opening 7 of the container 3.

  In the light emitting device 1, the light emitted from the light emitting element 5 is transmitted through the light wavelength conversion member 9 having translucency, and a part of the light is wavelength-converted inside the light wavelength conversion member 9 to emit light. To do. That is, the light wavelength conversion member 9 emits fluorescence having a wavelength different from the wavelength of the light emitted from the light emitting element 5.

For example, blue light emitted from the LD is wavelength-converted by the light wavelength conversion member 9, so that white light as a whole is irradiated from the light wavelength conversion member 9 to the outside (for example, upward in FIG. 1).
[1-2. Optical wavelength conversion member]
Next, the light wavelength conversion member 9 will be described.

The light wavelength conversion member 9 of the present embodiment includes Al ₂ O ₃ crystal particles and crystal particles of a component represented by the chemical formula A ₃ B ₅ O ₁₂ : Ce (ie, A ₃ B ₅ O ₁₂ : Ce crystal particles). It is composed of a ceramic sintered body which is a polycrystalline body as a main component.

In this light wavelength conversion member 9, A and B in A ₃ B ₅ O ₁₂ are at least one element selected from the following element group. In addition, at least one element selected from the following element group is distributed between each crystal grain of the ceramic sintered body and the crystal grain boundary, and the element distributed within each crystal grain and the crystal grain boundary Has a higher grain boundary concentration than the concentration in each crystal grain.

A: Sc, Y, lanthanoid (excluding Ce)
B: Al, Ga
Further, in the light wavelength conversion member 9 of the present embodiment, the concentration of Ce in the A ₃ B ₅ O ₁₂ : Ce crystal particles can be 10.0 mol% or less (excluding 0) with respect to the element A. .

Furthermore, the optical wavelength conversion member 9 of this embodiment, _A 3 _B 5 _O 12 occupying the ceramic sintered body: as a percentage of Ce crystal grains can be employed 3~70vol%.
[1-3. effect]
Next, effects of the embodiment will be described.

  In the light wavelength conversion member 9 of the present embodiment, the element distributed in each crystal grain and the crystal grain boundary has a higher crystal grain boundary concentration than the concentration in each crystal grain. (That is, the color variation is small).

  Moreover, since the light wavelength conversion member 9 of this embodiment has high thermal conductivity, even when the light source has a high output, it suppresses the influence of heat, for example, suppresses the loss of light. Can do.

  Furthermore, since the light wavelength conversion member 9 of this embodiment is a ceramic sintered body, the strength is high, and even when light is repeatedly irradiated from the light source, the performance is not easily deteriorated, and in addition, the weather resistance is improved. Also has the advantage of being superior.

In addition, when the Ce concentration in the A ₃ B ₅ O ₁₂ : Ce crystal particles is 10 mol% or less (not including 0) with respect to the element A, it is preferable because high fluorescence intensity can be realized.
Furthermore, when the ratio of A ₃ B ₅ O ₁₂ : Ce crystal particles in the ceramic sintered body is _{3 to} 70 vol%, there is an advantage that sufficient translucency is obtained and the emission intensity is increased. is there.

Therefore, the light emitting device 1 provided with the light wavelength conversion member 9 has an effect of generating fluorescence having high fluorescence intensity and high color uniformity.
[2. Example]
Next, specific examples will be described.
[2-1. Examples 1 to 3]
<Example 1>
Under the conditions shown in Table 1 below, samples of ceramic sintered bodies No. 1 to No. 4 were produced. Of the samples, Nos. 1 to 3 are samples within the scope of the present invention, and No. 4 is a sample outside the scope of the present invention (comparative example).

Specifically, for each sample, the ratio of YAG (Y ₃ Al ₅ O ₁₂ ) in the ceramic sintered body (that is, the ceramic sintered body constituting the light wavelength conversion member) is 21 vol%. In addition, Al ₂ O ₃ (average particle size 0.3 μm), Y ₂ O ₃ (average particle size 1.2 μm), CeO ₂ (average particle size) so that the Ce concentration is 1 mol% with respect to Y in YAG. Diameter 1.5 μm).

This was put into a ball mill together with an organic solvent and a predetermined amount of a dispersant (2 wt% in terms of solid matter with respect to the raw material powder), and pulverized and mixed for 12 hours.
The mixing and grinding was performed according to the following procedure.

First, each powder was produced by any one of the following methods (1) to (4).
(1) Crushing and mixing for 10 hr only with Al ₂ O ₃
(2) 10 hr pulverization and mixing only with Al ₂ O ₃ and CeO ₂
(3) 10 hr pulverization and mixing only with Y ₂ O ₃ and CeO ₂
(4) Al ₂ O ₃ , Y ₂ O ₃ , CeO ₂ for 10 hr pulverized and mixed Then, the powders of (1) to (4) were mixed and pulverized under the following conditions to prepare each slurry of AD .

A: Slurry in which powders of (1) and (4) were mixed and mixed for 2 hours B: Slurry in which powders of (2) and (4) were mixed and mixed for 2 hours,
C: Slurry obtained by mixing the powders of (2), (3) and (4) and adding and mixing for 2 hr D: Slurry obtained by mixing and grinding the powder of (4) for 2 hr
Next, as shown in Table 1 below, a sheet molded body was produced by the doctor blade method using each of the obtained slurries. The sheet compact was degreased and fired in an air atmosphere at a firing temperature of 1450 ° C. to 1750 ° C. and a holding time of 3 to 20 hours. As a result, No. 1 to 4 ceramic sintered body samples were obtained. The size of the ceramic sintered body is 20 mm square x 0.5 mm thickness.

  As the dispersant, for example, polydisperse dispersant SN Dispersant 5468 manufactured by San Nopco, or Marialim AKM-053 manufactured by Nippon Oil & Fats Co., Ltd. can be used.

Next, the following characteristics (a) to (e) were investigated for the obtained ceramic sintered body in the same manner as in other examples described later. The results are shown in Table 1 below.
(A) Relative Density The relative density of the obtained ceramic sintered body was calculated by measuring the density by the Archimedes method and converting the measured density to the relative density.

(B) Grain boundary component For each sample, a focused ion beam device (FIB device: Focused Ion Beam system) is used to measure 100 nm from an arbitrary portion of the ceramic sintered body (for example, the central portion of the sintered body). Four slices were cut out. The object of observation was an arbitrary surface (for example, the central portion of the thin piece) in the thin piece.

  And the arbitrary surface in each sample was observed with the scanning transmission electron microscope (STEM: Scanning Transmission Electron Microscope), and the crystal grain boundary was confirmed.

  Next, in each sample in which the crystal grain boundary is confirmed, the concentration of Ce element in the crystal grain and the crystal grain boundary is measured by an energy dispersive X-ray spectrometer (EDS: Energy Dispersive X-ray Spectrometer). The presence or absence of elements was confirmed.

  Specifically, as shown in FIGS. 2 to 5 to be described later, in order to examine the concentration of Ce element in the crystal grain and the crystal grain boundary, linearly so as to include the crystal grain boundary and the inside of the crystal grain on both sides thereof. A predetermined range (that is, analysis distance) was set, and the concentration of Ce element in the range was continuously measured (so-called line analysis was performed).

(C) Fluorescence intensity A sample processed to 13 mm square x 0.5 mm thickness is irradiated with blue LD light having a wavelength of 465 nm to a width of 0.5 mm with a lens, and the transmitted light is collected with the lens. The emission intensity was measured with a power sensor. At this time, the output power density was set to 40 W / mm ² . The strength was evaluated by a relative value when the strength of the YAG: Ce single crystal was 100.

(E) Color variation The color variation was evaluated by measuring chromaticity variation with a color illuminometer.
Specifically, blue LD light having a wavelength of 462 nm is condensed with a lens to a width of 0.4 mm with respect to a sample processed into a 20 mm square × thickness of 0.5 mm, and this is irradiated and transmitted from the opposite surface. The chromaticity of the incoming light was measured with a color illuminometer.

  Irradiation was carried out by setting an 18 mm square region at the center of the irradiation surface (sample surface) of the sample, and performing 3 mm intervals in the region, and evaluating the variation (ΔX) in the chromaticity (X direction). Here, the variation (ΔX) is the maximum value of deviation of chromaticity (X direction).

  Of the results obtained for each sample as described above, the fluorescence intensity and color variation can be evaluated according to the following evaluation criteria. Other examples can be similarly evaluated.

The fluorescence intensity is considered to be preferably 120 or more. Regarding color variation, ΔX <0.015 is considered preferable.
Below, about the present Example 1, the evaluation etc. based on the said evaluation criteria are demonstrated.

In any sample of Example 1, the relative density was 99% or more, and the sample was sufficiently densified.
Further, as shown in Table 1, Nos. 1 to 3 in which more Ce elements are distributed in the crystal grain boundaries than each crystal grain have high fluorescence intensity and small color variation, both of which are good results. It became. On the other hand, No. 4 with a small concentration difference of Ce had low fluorescence intensity and large color variation.

In Table 1, “Al ₂ O ₃ —Al ₂ O ₃ ” indicates a grain boundary between Al ₂ O ₃ crystal particles and Al ₂ O ₃ crystal particles, and “Al ₂ O ₃ -A ₃ B ₅ “O ₁₂ ” indicates a grain boundary between Al ₂ O ₃ crystal particles and A ₃ B ₅ O ₁₂ : Ce crystal particles, and “A ₃ B ₅ O ₁₂ -A ₃ B ₅ O ₁₂ ” indicates A ₃ B ₅ O _12: Ce crystal grains and _a 3 _B 5 _O 12: shows the grain boundary of the Ce crystal grains. In each grain boundary, “present” means that the maximum Ce concentration peak in the line analysis is at the grain boundary, that is, the Ce concentration in the grain boundary is higher than the Ce concentration in each crystal grain. ing.

<Example 2>
As shown in Table 1 below, samples of ceramic sintered bodies (samples Nos. 5 to 14) were produced by the same manufacturing method as in Example 1 and evaluated in the same manner.

Here, the raw material compounding ratio was changed so that the Ce concentration with respect to Y in A ₃ B ₅ O ₁₂ (YAG) of the ceramic sintered body was 0 to 15 mol%.
As a result, all samples were sufficiently densified with a relative density of 99% or more.

It was also found that Ce elements were distributed more in the grain boundaries than in the crystal grains.
And No. 6-12 in which Ce density | concentration is 10 mol% or less (however, it is not 0) brought a result with favorable fluorescence intensity and color variation.

On the other hand, No. 5 containing no Ce could not measure fluorescence intensity and color variation.
In addition, Nos. 13 and 14 with high Ce concentration had low fluorescence intensity.
<Example 3>
As shown in Table 1 below, samples of ceramic sintered bodies (samples Nos. 15 to 22) were prepared and evaluated in the same manner as in Example 1.

However, the raw material compounding ratio was changed so that the amount of A ₃ B ₅ O ₁₂ : Ce (YAG: Ce amount) in the ceramic sintered body was 1 to 80 vol%.
As a result, all samples were sufficiently densified with a relative density of 99% or more.

It was also found that Ce elements were distributed more in the grain boundaries than in the crystal grains.
And No. 16-21 in which the amount of YAG: Ce is in the range of 1 to 70 vol% gave good results in both fluorescence intensity and color variation.

On the other hand, No. 15 with a small amount of YAG: Ce and No. 22 with a large amount of YAG: Ce had low fluorescence intensity and slightly increased color variation.
<Example 4>
With the same manufacturing method as in Example 1, as shown in Table 1 below, ceramic sintered body samples (samples Nos. 23 to 43) were prepared and evaluated in the same manner.

However, not only Y ₂ O ₃ powder at the time of preparation, but also Lu ₂ O ₃ (average particle size 1.3 μm) or Yb ₂ O ₃ (average particle size 1.5 μm), Gd ₂ O ₃ (average particle size 1.5 μm) ), Tb ₂ O ₃ (average particle size: 1.6 μm), and Ga ₂ O ₃ (average particle size: 1.3 μm) at least one powder so that a predetermined A ₃ B ₅ O ₁₂ : Ce can be synthesized. The blending ratio was changed.

As a result, all samples were sufficiently densified with a relative density of 99% or more.
It was also found that Ce elements were distributed more in the grain boundaries than in the crystal grains.

  In all samples, both the fluorescence intensity and the color variation were satisfactory.

[2-2. Line analysis]
Here, the above-described line analysis and the result will be described.
Fig.2 (a) is a BF-STEM image (magnification 200,000 times) of the sample of No.3. Here, as shown in FIG. 2 (a), with respect to the range of horizontal lines crossing the range of “YAG (ie, YAG crystal particles) —grain boundary—Al ₂ O ₃ (ie, Al ₂ O ₃ crystal particles)” The line analysis was performed.

The result is shown in FIG. 2B, and it can be seen that the Ce concentration is maximum at the crystal grain boundaries as compared with the crystal grains on both sides.
The horizontal axis of the graph of FIG. 2B is a position on the crystal grain boundary from a position A1 in YAG (that is, YAG crystal grain) as a position on a straight line crossing the crystal grain boundary shown in FIG. Each position from A2 to position A3 in Al ₂ O ₃ (ie, Al ₂ O ₃ crystal particles) is shown. The distance from the position A1 to the position A3 is about 100 nm. On the other hand, the vertical axis represents the concentration of Ce. Hereinafter, for other line analysis, the range of line analysis is not “A1, A2, A3” but “B1, B2, B3”, “C1, C2, C3”, “D1, D2, D3” The point is the same, though different.

FIG. 3A is a BF-STEM image (magnification 200,000 times) of the sample No. 8. Here, as shown in FIG. 3 (a), - for a range of horizontal lines across the _"Al 2 _{O 3} crystal grain boundary _-Al 2 _{O 3"} range (B1~B2~B3), the line Analysis Went.

The result is shown in FIG. 3B, and it can be seen that the Ce concentration is maximum in the crystal grain boundaries as compared with the crystal grains on both sides.
4A is a BF-STEM image (magnification 200,000 times) of the sample No. 18. FIG. Here, as shown in FIG. 4 (a), for a range of horizontal lines across the range of "YAG- grain boundaries _-Al 2 _{O 3"} (C1~C2~C3), it was subjected to the line Analysis .

The result is shown in FIG. 4B, and it can be seen that the Ce concentration is maximum in the crystal grain boundaries as compared with the inside of the crystal grains on both sides.
FIG. 5A is a BF-STEM image (magnification of 200,000 times) of the No. 20 sample. Here, as shown to Fig.5 (a), the said line analysis was performed with respect to the range (D1-D2-D3) of the horizontal line which crosses the range of "YAG-grain boundary-YAG".

The result is shown in FIG. 5B, and it can be seen that the Ce concentration is maximum in the crystal grain boundaries as compared with the crystal grains on both sides.
[3. Other Embodiments]
It goes without saying that the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the present invention.

  (1) For example, in the above embodiment, the atmospheric pressure firing method in the air was used as the firing method, but in addition, a vacuum atmosphere firing method, a reducing atmosphere firing method, a hot press (HP) method, hot isotropy, etc. A sample having equivalent performance can also be produced by a pressure and pressure (HIP) method or a firing method combining these methods.

(2) Examples of uses of the light wavelength conversion member and the light emitting device include various uses such as phosphors, light wavelength conversion devices, headlamps, illumination, and optical devices such as projectors.
(3) The configurations of the above embodiments can be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 5 ... Light emitting element 9 ... Light wavelength conversion member

Claims (4)

A light wavelength conversion member composed of a ceramic sintered body that is a polycrystalline body mainly composed of Al ₂ O ₃ crystal particles and crystal particles of a component represented by the chemical formula A ₃ B ₅ O ₁₂ : Ce. ,
A and B in the A ₃ B ₅ O ₁₂ are at least one element selected from the following element group;
In addition, at least one element selected from the following element group is distributed between the crystal grains of the ceramic sintered body and the crystal grain boundaries, and the crystal grains and the crystal grain boundaries The element distributed in the light wavelength conversion member, wherein the concentration of the crystal grain boundary is higher than the concentration in each crystal grain.
A: Sc, Y, lanthanoid (excluding Ce)
B: Al, Ga The concentration of Ce in the crystal grains of the component represented by A ₃ B ₅ O ₁₂ : Ce is 10.0 mol% or less (excluding 0) with respect to the element A. Item 4. The light wavelength conversion member according to Item 1. _3. The light wavelength conversion according to claim 1, wherein a ratio of the crystal particles of the component represented by A ₃ B ₅ O ₁₂ : Ce in the ceramic sintered body is _{3 to} 70 vol%. Element.   The light-emitting device provided with the light wavelength conversion member of any one of the said Claims 1-3.