Wave-length conversion inorganic member, and method for manufacturing the same

1. A wave-length conversion inorganic member comprising:

a base body; and

an inorganic particle layer on the base body, the inorganic particle layer including particles of an inorganic wave-length conversion substance which is configured to absorb light of a first wave-length and to emit light of a second wave-length different from the first wave-length,

the inorganic particle layer comprising

an agglomerate of a plurality of the particles, wherein each of the plurality of the particles are in contact with at least one of the other particles or the base body; and

a cover layer comprising an inorganic material, and the cover layer continuously covering a surface of the base body and surfaces of the particles,

the inorganic particle layer having an interstice enclosed by the particles, or by the particles and one of the base body and the cover layer,

wherein each of the plurality of the particles of the wave-length conversion substance is bonded to at least one of the other particles or the base body by an inorganic binder,

wherein the inorganic binder is a hydroxide or a carbonate of an alkaline earth metal, and

wherein the base body comprises an inorganic wave-length conversion substance which absorbs the light of the first wave-length and emits light of a third wave-length different from the first wave-length and the second wave-length.

2. The wave-length conversion inorganic member according to claim 1 ,

wherein the base body comprises a translucent material.

3. The wave-length conversion inorganic member according to claim 1 ,

wherein the base body and the inorganic particle layer has a boundary surface therebetween, and

wherein the boundary surface is configured to reflect the light of the first wave-length and the light of the second wave-length.

4. The wave-length conversion inorganic member according to claim 1 , wherein the base body comprises a light source which is configured to emit light of the first wavelength.

5. The wave-length conversion inorganic member according to claim 1 , wherein the inorganic particle layer has a plurality of interstices, and has a density of 1% to 50%.

6. The wave-length conversion inorganic member according to claim 1 ,

wherein the particles of the wave-length conversion substance have an average particle size of 0.1 μm to 100 μm, and

wherein the cover layer has an average thickness of 10 μm to 50 μm.

7. The wave-length conversion inorganic member according to claim 1 ,

wherein the inorganic particle layer has a concave and convex surface formed by variations in particle sizes of the particles of the wave-length conversion substance.

8. The wave-length conversion inorganic member according to claim 1 ,

wherein the cover layer is formed by atomic layer deposition.

9. The wave-length conversion inorganic member according to claim 1 ,

wherein the cover layer contains at least one compound selected from the group consisting of Al2O3, SiO2, ZrO2, HfO2, TiO2, ZnO, Ta2O5, Nb2O5, In2O3, SnO2, TiN, and AlN.

10. The wave-length conversion inorganic member according to claim 1 ,

wherein the wave-length conversion substance contains at least one compound selected from the group consisting of sulfide phosphor, halogen-silicate phosphor, nitride phosphor, and oxynitride phosphor.

11. The wave-length conversion inorganic member according to claim 1 , wherein the interstice is filled with a filler material.

12. The wave-length conversion inorganic member according to claim 11 , wherein the filler material is a gas layer or a solid.

13. The wave-length conversion inorganic member according to claim 11 , wherein the filler material is the same material as a material of the cover layer.