GREEN-EMITTING PHOSPHOR PARTICLES, METHOD FOR MANUFACTURING GREEN-EMITTING PHOSPHOR PARTICLES, COLOR CONVERSION SHEET, LIGHT-EMITTING DEVICE, AND IMAGE DISPLAY DEVICE ASSEMBLY

• US 20160061418A1
• Filed: 11/09/2015
• Published: 03/03/2016
• Est. Priority Date: 05/10/2010
• Status: Active Grant

• Current Assignee: Dexerials Corporation
• Original Assignee: Dexerials Corporation
• Inventors: IZAWA, Takamasa, KUSUNOKI, Tsuneo, IGARASHI, Takahiro
• Granted Patent: US 10,047,931 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C09K 11/7731 with alkaline earth metals
• CPC Class Codes: C09K 11/7741 Sulfates
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: G02B 5/201 in the form of arrays
• 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 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 2924/00014 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 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

A method for manufacturing green-emitting phosphor particles including the steps of producing a powder containing europium and strontium from a solution containing a europium compound and a strontium compound, mixing the resulting powder and a powdered gallium compound, and performing firing.

Claims

1. A method for manufacturing green-emitting phosphor particles comprising the steps of:

producing a powder containing europium and strontium from a solution containing a europium compound and a strontium compound;

mixing the resulting powder and a powdered gallium compound; and

performing firing.

2. The method for manufacturing green-emitting phosphor particles according to claim 1,

wherein the powder comprising (Sr,Eu)SO₃ is produced by dropping a sulfite into the solution containing a europium compound and a strontium compound.

3. The method for manufacturing green-emitting phosphor particles according to claim 1,

wherein the mixing of the powder and the powdered gallium compound is performed by using a ball mill.

6. The method for manufacturing green-emitting phosphor particles according to claim 1,

wherein the firing is performed in a hydrogen sulfide gas atmosphere.

7. The method for manufacturing green-emitting phosphor particles according to claim 1,

wherein the green-emitting phosphor particles comprise Sr_1-xGa₂S₄:

Eu_x (where 0.10≦

x≦

0.20) and

the value of (internal quantum efficiency/absorption efficiency) is 0.7 or more.

4. A method for manufacturing green-emitting phosphor particles comprising the steps of:

producing a powder by

adding a powdered gallium compound to a solution containing a europium compound and a strontium compound and

adding a salt to precipitate the europium compound and the strontium compound; and

firing the resulting powder.

5. The method for manufacturing green-emitting phosphor particles according to claim 4,

wherein the powder comprising Sr, Eu, and Ga is produced by

adding the powdered gallium compound to the solution containing a europium compound and a strontium compound and

dropping a sulfite.

8. A color conversion sheet comprising:

a first transparent base member;

a second transparent base member; and

a color conversion layer sandwiched between the first transparent base member and the second transparent base member,

wherein the color conversion layer is formed from at least green-emitting phosphor particles and

the green-emitting phosphor particles are composed of (Sr,Ba,Ca)_1-xGa₂S₄;

Eu_x (where 0.10≦

x≦

0.20) and

the value of (internal quantum efficiency/absorption efficiency) is 0.7 or more.

9. The color conversion sheet according to claim 8,

wherein the color conversion layer comprises green-emitting phosphor particles and red-emitting particles.

10. The color conversion sheet according to claim 9,

wherein blue light is incident and white light is emitted.

11. A light-emitting device comprising:

(a) a light source; and

(b) phosphor particles which are excited by the light emitted from the light source,

wherein the phosphor particles are composed of at least green-emitting phosphor particles and

the green-emitting phosphor particles are composed of (Sr,Ba,Ca)_1-xGa₂S₄;

Eu_x (where 0.10≦

x≦

0.20) and

the value of (internal quantum efficiency/absorption efficiency) is 0.7 or more.

12. The light-emitting device according to claim 11,

wherein the phosphor particles comprise green-emitting phosphor particles and red-emitting particles.

13. The light-emitting device according to claim 11,

wherein layered phosphor particles are disposed on a first surface of a transparent base member and

the light source is disposed opposing to a second surface opposite to the first surface of the transparent base member.

14. The light-emitting device according to claim 13,

wherein the phosphor particles are covered with the second transparent base member.

15. An image display device assembly comprising;

(A) an image display device; and

(B) a light-emitting device to illuminate the image display device from the back,

wherein the light-emitting device includes

(a) a light source; and

(b) phosphor particles which are excited by the light emitted from the light source,

the phosphor particles are composed of at least green-emitting phosphor particles,

the green-emitting phosphor particles are composed of (Sr,Ba,Ca)_1-xGa₂S₄;

Eu_x (where 0.10≦

x≦

0.20), and

the value of (internal quantum efficiency/absorption efficiency) is 0.7 or more.

16. The image display device assembly according to claim 15,

wherein the phosphor particles comprise green-emitting phosphor particles and red-emitting particles.

17. The image display device assembly according to claim 15,

wherein layered phosphor particles are disposed on a first surface of a transparent base member and

the light source is disposed opposing to a second surface opposite to the first surface of the transparent base member.

18. The image display device assembly according to claim 17,

wherein the phosphor particles are covered with a second transparent base member.

19. Green-emitting phosphor particles comprising (Sr,Ba,Ca)_1-xGa₂S₄:

Eu_x (where 0.10≦

x≦

0.20),

wherein the value of (internal quantum efficiency/absorption efficiency) is 0.7 or more.

20. The green-emitting phosphor particles according to claim 19,

wherein the median diameter is 1 μ

m to 7 μ

m.