Green-emitting phosphor particles, method for manufacturing green-emitting phosphor particles, color conversion sheet, light-emitting device, and image display device assembly

• US 10,047,931 B2
• Filed: 11/09/2015
• Issued: 08/14/2018
• Est. Priority Date: 05/10/2010
• Status: Active Grant

• Current Assignee: Dexerials Corporation
• Original Assignee: Dexerials Corporation
• Inventors: Izawa, Takamasa, Kusunoki, Tsuneo, Igarashi, Takahiro
• Primary Examiner(s): Koslow, C Melissa
• Application Number:
  US14/936,033
• Publication Number:
  US 20160061418A1
• Time in Patent Office: 1,009 Days
• 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 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 M_1-xGa₂S₄;

Eu_x (where 0.10≤

x≤

0.20, and M is at least one of Sr, Ca, and Ba) and

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

2. The color conversion sheet according to claim 1,

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

3. The color conversion sheet according to claim 2,

wherein the sheet emits white light when blue light enters the sheet.

4. 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 M_1-xGa₂S₄;

Eu_x (where 0.10≤

x≤

0.20, and M is at least one of Sr, Ca, and Ba) and

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

5. The light-emitting device according to claim 4,

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

6. The light-emitting device according to claim 4,

wherein the phosphor particles are layered and 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.

7. The light-emitting device according to claim 6,

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

8. 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 M_1-xGa₂S₄;

Eu_x (where 0.10≤

x≤

0.20, and M is at least one of Sr, Ca, and Ba), and

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

9. The image display device assembly according to claim 8,

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

10. The image display device assembly according to claim 8,

wherein the phosphor particles are layered and 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.

11. The image display device assembly according to claim 10,

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

12. Green-emitting phosphor particles comprising M_1-xGa₂S₄:

Eu_x (where 0.10≤

x≤

0.20, and M is at least one of Sr, Ca, and Ba),

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

13. The green-emitting phosphor particles according to claim 12,

wherein the median diameter is 1 μ

m to 7 μ

m.