Phosphor, Production Method Thereof and Light Emitting Instrument

• US 20080001126A1
• Filed: 09/16/2005
• Published: 01/03/2008
• Est. Priority Date: 09/22/2004
• Status: Abandoned Application

• Current Assignee: National Institute for Materials Science
• Original Assignee: National Institute for Materials Science
• Inventors: Hirosaki, Naoto
• Application Number:
  US11/663,461
• Publication Number:
  US 20080001126A1
• Time in Patent Office: Days
• US Class Current: 252/519.51
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3852 Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
• CPC Class Codes: C04B 2235/3865 Aluminium nitrides
• CPC Class Codes: C04B 2235/3878 Alpha silicon nitrides
• CPC Class Codes: C04B 2235/3895 Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/5409 expressed by specific surface values
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/761 Unit-cell parameters, e.g. lattice constants
• CPC Class Codes: C04B 2235/766 Trigonal symmetry, e.g. alpha-Si3N4 or alpha-Sialon
• CPC Class Codes: C04B 2235/767 Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites
• CPC Class Codes: C04B 35/584 based on silicon nitride
• CPC Class Codes: C04B 35/597 based on silicon oxynitride, e.g. SIALONS
• CPC Class Codes: C04B 35/6262 of calcined, sintered clinker or ceramics
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: H01J 29/20 characterised by the luminescent material
• CPC Class Codes: H01L 2224/45144 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/8592 : Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials

Abstract

The present invention aims at providing a chemically stabilized inorganic phosphor having an orange or red emission characteristic at higher luminance, and a light emitting instrument adopting the phosphor, for a lighting instrument excellent in color rendering property and for an image displaying apparatus excellent in durability. The solving means resides in provision of a fundamental phosphor comprising:

• • a crystal represented by A₂Si_5−xAl_xO_xN_8−x (A is a mixture of one kind or two or more kinds of element(s) selected from Mg, Ca, Sr, and Ba; and x is a value between 0.05 inclusive and 0.8 inclusive); and a metallic element M (M is one kind or two or more kinds of element(s) selected from Mn, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb) dissolved, in a solid state, in the crystal.

Claims

1. A phosphor, wherein the phosphor includes, as a main component, an inorganic compound comprising:

a crystal represented by A₂Si<sub>5−

x</sub>Al_xO_xN<sub>8−

x</sub> (A is a mixture of one kind or two or more kinds of element(s) selected from Mg, Ca, Sr, and Ba; and

x is a value between 0.05 inclusive and 0.8 inclusive); and

a metallic element M (M is one kind or two or more kinds of element(s) selected from Mn, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb) dissolved, in a solid state, in the crystal.

2. The phosphor of claim 1, wherein x is a value between 0.05 inclusive and 0.5 inclusive.

3. The phosphor of claim 1, wherein the inorganic compound comprises a solid solution crystal represented by A₂₋

ySi<sub>5−

x</sub>Al_xO_xN<sub>8−

x</sub>;

M_y, and y is a value in a range of 0.001≦

y≦

0.5.

4. The phosphor of claim 1, wherein the inorganic compound includes at least Eu as the metallic element M.

5. The phosphor of claim 1, wherein the metallic element M is Eu and the metallic element A is Sr or Ca.

7. The phosphor of claim 1, wherein the inorganic compound comprises a solid solution crystal represented by Sr_aCa_bSi₅₋

xAl_xO_xN<sub>8−

x</sub>;

Eu_y, and values of “

a” and

“

b”

are within ranges, respectively, defined by;

a+b=2−

y, and
0.2≦

a/(a+b)≦

1.8.

8. The phosphor of claim 1, wherein the inorganic compound is a powder having an averaged particle size between 0.1 μ

m inclusive and 20 μ

m inclusive.

9. The phosphor of claim 1, wherein the phosphor further includes an additional crystal phase or amorphous phase in addition to the inorganic compound;

and that the inorganic compound is included at a content of 10 mass % or more.

10. The phosphor of claim 9, wherein the content of the inorganic compound is 50 mass % or more.

11. The phosphor of claim 10, wherein the additional crystal phase or amorphous phase is an inorganic substance having electroconductivity.

12. The phosphor of claim 11, wherein the inorganic substance having electroconductivity is oxide, oxynitride, nitride, or a mixture thereof including at least one kind element selected from Zn, Ga, In, and Sn.

13. The phosphor of claim 1, wherein the phosphor emits orange or red fluorescence at a wavelength between 570 nm inclusive and 700 nm inclusive, by irradiation of an excitation source comprising ultraviolet light, or visible light, between 100 nm inclusive and 550 nm inclusive, or electron beam.

14. The phosphor of claim 13, wherein the phosphor emits fluorescence having (x, y) values on CIE chromaticity coordinates satisfying a condition of 0.4≦

x≦

0.7, upon irradiation by the excitation source.

15. A production method of the phosphor of claim 1, wherein the method comprises the step of:

firing a starting material mixture in a nitrogen atmosphere at a pressure between 0.1 MPa inclusive and 100 MPa inclusive at a temperature range between 1,200°

C. inclusive and 2,200°

C. inclusive,

wherein the starting material mixture is a mixture of metallic compounds, and is capable of constituting a composition comprising M, A, Si, Al, O, and N (M is one kind or two or more kinds of element(s) selected from Mn, Ce, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb; and

A is one kind or two or more kinds of element(s) selected from Mg, Ca, Sr, and Ba).

25. A lighting instrument constituted of a light-emitting source and a phosphor, wherein the phosphor includes the phosphor of claim 1.

26. The lighting instrument of claim 25, wherein the light-emitting source is an LED for emitting light at a wavelength of 330 to 500 nm.

27. The lighting instrument of claim 25, wherein the light-emitting source is an LED for emitting light at a wavelength between 330 and 420 nm;

and

the phosphor further includes;

a blue-aimed phosphor having an emission peak at a wavelength between 420 nm inclusive and 500 nm inclusive by the light; and

a green-aimed phosphor having an emission peak at a wavelength between 500 nm inclusive and 570 nm inclusive by the light.

28. The lighting instrument of claim 25, wherein the light-emitting source is an LED for emitting light at a wavelength between 420 and 500 nm;

and

phosphor further includes a green-aimed phosphor having an emission peak at a wavelength between 500 nm inclusive and 570 nm inclusive by the light.

29. The lighting instrument of claim 25, wherein the light-emitting source is an LED for emitting light at a wavelength between 420 and 500 nm;

and

the phosphor further includes a yellow-aimed phosphor having an emission peak at a wavelength between 550 nm inclusive and 600 nm inclusive by the light.

32. An image displaying apparatus constituted of an excitation source and a phosphor, wherein the phosphor includes the phosphor of claim 1.

6. (canceled)

16-24. -24. (canceled)

30-31. -31. (canceled)

33-34. -34. (canceled)