Phosphor, manufacture thereof, light-emitting device, and image display device

Patent metadata

Field	Value
Publication number	US-9062252-B2
Application number	US-201213690340-A
Country	US
Kind code	B2
Filing date	Nov 30, 2012
Priority date	Nov 7, 2011
Publication date	Jun 23, 2015
Grant date	Jun 23, 2015

Abstract

Provided is a chemically-thermally stable phosphor having different emission characteristics from the conventional and exhibiting high emission intensity with an LED of 470 nm or less. A phosphor of the present invention includes an inorganic crystal of a crystal represented by Sr 1 Si 3 Al 2 O 4 N 4 , another inorganic crystal represented by A 1 (D,E) 5 X 8 and having the same crystal structure as Sr 1 Si 3 Al 2 O 4 N 4 , and/or a solid-solution crystal thereof, all with M (one or more kinds of elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) being solid-solved, wherein A is one or more kinds selected from Mg, Ca, Sr and Ba; D is one or more kinds selected from Si, Ge, Sn, Ti, Zr and Hf; E is one or more kinds selected from B, Al, Ga, In, Sc, Y and La; and X is one or more kinds selected from O, N and F.

First claim

What is claimed is:

1. A phosphor comprising: an inorganic compound comprising:
an inorganic crystal constituted of a crystal represented by Sr 1 Si 3 Al 2 O 4 N 4 and an M element being solid-solved into the inorganic crystal, wherein M is one or more kinds of elements selected from a group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb; or
another inorganic crystal represented by A 1 (D,E) 5 X 8 and having a same crystal structure as the crystal represented by the Sr 1 Si 3 Al 2 O 4 N 4 , and the M element being solid-solved into the another inorganic crystal, wherein A is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, and Ba, D is one or more kinds of elements selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf, E is one or more kinds of elements selected from the group consisting of B, Al, Ga, In, Sc, Y, and La, and X is one or more kinds of elements selected from the group consisting of O, N, and F; or
a solid-solution crystal of the inorganic crystal or the another inorganic crystal.

2. The phosphor according to claim 1 ,
wherein the another inorganic crystal is a crystal represented by A 1 Si 3 Al 2 O 4 N 4 .

3. The phosphor according to claim 2 ,
wherein the A element includes either or both of Sr and Ba, the D element includes Si, the E element includes Al, the X element includes N, and the X element further includes O if necessary.

4. The phosphor according to claim 1 ,
wherein the M element includes Eu.

5. The phosphor according to claim 1 ,
wherein the inorganic crystal is a crystal in a monoclinic system.

6. The phosphor according to claim 1 ,
wherein the inorganic crystal is a crystal in a monoclinic system and has a symmetry in a space group P2 1 , and lattice constants a, b, and c have values in following ranges:
a= 0.72516±0.05 nm;

b= 0.93431±0.05 nm; and

c= 1.08761±0.05 nm, and

wherein “±0.05” is a tolerance.

7. The phosphor according to claim 1 ,
wherein the another inorganic crystal is Ba 1 Si 3 Al 2 O 4 N 4 or (Sr, Ba) 1 Si 3 Al 2 O 4 N 4 .

8. The phosphor according to claim 1 ,
wherein the another inorganic crystal is represented by a composition formula:
(Sr,Ba) 1 Si 3−x Al 2+x O 4+x N 4−x ,

wherein −1≦x≦2.

9. The phosphor according to claim 1 ,
wherein the inorganic compound consists of a crystal represented by:
A 1 Si 3−x Al 2+x O 4+x N 4−x ,

wherein −1≦x≦2, and Eu is solid-solved therein.

10. The phosphor according to claim 9 ,
wherein the A element is a combination of Sr and Ba.

11. The phosphor according to claim 10 ,
wherein the inorganic crystal is represented, using parameters x and y, by:
Eu y (Sr,Ba) 1 Si 3−x Al 2+x O 4+x N 4−x

wherein −1≦x≦2, and 0.0001≦y≦0.5.

12. The phosphor according to claim 9 ,
wherein the x is equal to 0.

13. The phosphor according to claim 9 , wherein:
the A element is a combination of Sr and Ba,
the x is equal to 0, and
fluorescence of a blue color having 440 nm or more to 520 nm or less is emitted upon irradiation of light having 295 to 420 nm.

14. The phosphor according to claim 1 ,
wherein the inorganic compound includes a single crystal particle or an aggregate thereof having a mean particle diameter of 0.1 μm or more to 20 μm or less.

15. The phosphor according to claim 1 ,
wherein a sum of Fe, Co, and Ni impurity elements does not exceed 500 ppm.

16. The phosphor according to claim 1 , further comprising an amorphous phase or a crystal phase that is different from the inorganic compound in addition to the inorganic compound,
wherein a content amount of the inorganic compound is equal to or more than 20 mass %.

17. The phosphor according to claim 16 ,
wherein the amorphous phase or the crystal phase that is different from the inorganic compound is an inorganic substance having electronic conductivity.

18. The phosphor according to claim 17 ,
wherein the inorganic substance having the electrical conductivity is oxide, oxynitride, nitride, or a combination thereof, any one of which includes one or two or more kinds of elements selected from a group consisting of Zn, Al, Ga, In, and Sn.

19. The phosphor according to claim 16 ,
wherein the amorphous phase or the crystal phase that is different from the inorganic compound is another phosphor.

20. The phosphor according to claim 1 ,
wherein the phosphor emits fluorescent having a peak in a wavelength range of 440 nm to 520 nm upon irradiation of an excitation source.

21. The phosphor according to claim 20 ,
wherein the excitation source is a vacuum ultraviolet ray, an ultraviolet ray, or visible light, each of which has a wavelength that is in each specific range among from 100 nm to 420 nm, or an electron beam or an X-ray.

22. The phosphor according to claim 1 ,
wherein a color of light emitted upon irradiation of an excitation source satisfies, in terms of values of (x, y) of CIE 1931 chromaticity coordinates, conditions:
0.05 ≦x≦ 0.3; and
0.02 ≦y≦ 0.4.

23. A method of manufacturing a phosphor, the method comprising: the step of
firing a mixture of raw material in a temperature range of 1,200° C. or higher to 2,200° C. or lower in an inert atmosphere including nitrogen;
wherein the phosphor comprises: an inorganic compound comprising:
an inorganic crystal constituted of a crystal represented by Sr 1 Si 3 Al 2 O 4 N 4 and an M element being solid-solved into the inorganic crystal, wherein M is one or more kinds of elements selected from a group consisting of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb; or
another inorganic crystal represented by A 1 (D,E) 5 X 8 and having a same crystal structure as the crystal represented by the Sr 1 Si 3 Al 2 O 4 N 4 , and the M element being solid-solved into the another inorganic crystal, wherein A is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, and Ba, D is one or more kinds of elements selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf, E is one or more kinds of elements selected from the group consisting of B, Al, Ga, In, Sc, Y, and La, and X is one or more kinds of elements selected from the group consisting of O, N, and F; or
a solid-solution crystal of the inorganic crystal or the another inorganic crystal.

24. The method of manufacturing the phosphor according to claim 23 ,
wherein the mixture of raw material includes at least nitride or oxide of europium; nitride, oxide, or carbonate of strontium and/or nitride, oxide, or carbonate of barium; silicon oxide or silicon nitride; and aluminum oxide or aluminum nitride.

25. The method of manufacturing the phosphor according to claim 23 , wherein the inert atmosphere including nitrogen is a nitrogen gas atmosphere in a pressure range of 0.1 MPa or higher to 100 MPa or lower.

26. The method of manufacturing the phosphor according to claim 23 ,
wherein the step of firing is performed after the raw material in a form of powder or aggregate are filled in a container as being maintained with a filling rate of 40% or less in a bulk density.

27. The method of manufacturing the phosphor according to claim 23 ,
wherein a mean particle diameter of powder particles or aggregates of the raw material is 500 μm or less.

28. The method of manufacturing the phosphor according to claim 23 ,
wherein a mean particle diameter of aggregates of the raw mat

Assignees

• Hirosaki Naoto
• Takeda Takashi
• Funahashi Shiro
• Nat Inst For Materials Science

Inventors

• Hirosaki Naoto
• Takeda Takashi
• Funahashi Shiro

Classifications

• H10W90/756

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/01515

  Forming coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title