Red-emitting phosphors and associated devices

Patent metadata

Field	Value
Publication number	US-9567516-B2
Application number	US-201414303020-A
Country	US
Kind code	B2
Filing date	Jun 12, 2014
Priority date	Jun 12, 2014
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A process for synthesizing a manganese (Mn 4+ ) doped phosphor includes milling particles of the a phosphor precursor of formula I, and contacting the milled particles with a fluorine-containing oxidizing agent at an elevated temperature

A x [MF y ]:Mn 4+   (I)
wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MF y ] ion; y is 5, 6 or 7.

First claim

The invention claimed is:

1. A process for synthesizing a manganese doped phosphor, the process comprising:
dry milling particles of a phosphor precursor of formula I; and
A x [MF y ]:Mn 4+   (I)

contacting the dry milled particles with a fluorine-containing oxidizing agent in gaseous form at an elevated temperature, the fluorine-containing oxidizing agent comprising F 2 , SF 6 , BrF 5 , NH 4 HF 2 , NH 4 F, KF, AlF 3 , SbF 5 , ClF 3 , BrF 3 , KrF, XeF 2 , XeF 4 , NF 3 , SiF 4 , PbF 2 , ZnF 2 , SnF 2 , CdF 2 or combinations thereof; and
wherein,
A is Li, Na, K, Rb, Cs, or a combination thereof;
M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof;
x is 1, 2, or 3 and is equal to the absolute value of the charge of the [MF y ] ion;
y is 5, 6 or 7.

2. The process according to claim 1 , wherein M is Si, Ge, Sn, Ti, Zr, or a combination thereof.

3. The process according to claim 1 , wherein the particles of the phosphor precursor of formula I have a particle size distribution of a D50 value less than about 30 microns after the dry milling step.

4. The process according to claim 1 , wherein the particles of the phosphor precursor of formula I have a particle size distribution of a D50 value ranging from about 10 microns to about 25 microns after the dry milling step.

5. The process according to claim 1 , wherein the fluorine-containing oxidizing agent comprises F 2 .

6. The process according to claim 1 , wherein the dry milled particles are contacted with the fluorine-containing oxidizing agent at a temperature in a range from about 500° C. to about 600° C.

7. The process according to claim 1 , wherein the dry milled particles are contacted with the fluorine-containing oxidizing agent for at least four hours.

8. The process according to claim 1 , additionally comprising contacting the dry milled particles with a saturated solution of a compound of formula II in aqueous hydrofluoric acid after contacting the dry milled particles with the fluorine-containing oxidizing agent
A x [MF y ]  (II).

9. The process according to claim 1 , wherein
A is Na, K, Rb, Cs, or a combination thereof;
M is Si, Ge, Ti, or a combination thereof; and Y is 6.

10. The process according to claim 1 , wherein the phosphor precursor is K 2 SiF 6 :Mn 4+ .

11. A process for synthesizing a manganese doped phosphor, the process comprising:
dry milling particles of a phosphor precursor, wherein the precursor is selected from the group consisting of
(A) A 2 [MF 5 ]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, and combinations thereof; and where M is selected from Al, Ga, In, and combinations thereof;
(B) A 3 [MF 6 ]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, and combinations thereof; and where M is selected from Al, Ga, In, and combinations thereof;
(C) Zn 2 [MF 7 ]:Mn 4+ , where M is selected from Al, Ga, In, and combinations thereof;
(D) A[In 2 F 7 ]:Mn 4+ where A is selected from Li, Na, K, Rb, Cs, and combinations thereof;
(E) A 2 [MF 6 ]:Mn 4+ , where A is selected from Li, Na, K, Rb, Cs, and combinations thereof; and where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof;
(F) E[MF 6 ]:Mn 4+ , where E is selected from Mg, Ca, Sr, Ba, Zn, and combinations thereof; and where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof;
(G) Ba 0.65 Zr 0.35 F 2.70 :Mn 4+ ; and
(H) A 3 [ZrF 7 ]:Mn 4+ where A is selected from Li, Na, K, Rb, Cs and combinations thereof, and
contacting the dry milled particles with a fluorine-containing oxidizing agent in gaseous form at an elevated temperature, the fluorine-containing oxidizing agent comprising F 2 , SF 6 , BrF 5 , NH 4 HF 2 , NH 4 F, KF, AlF 3 , SbF 5 , ClF 3 , BrF 3 , KrF, XeF 2 , XeF 4 , NF 3 , SiF 4 , PbF 2 , ZnF 2 , SnF 2 , CdF 2 or combinations thereof.

Assignees

• Gen Electric

Inventors

• Murphy James Edward
• Setlur Anant Achyut
• Garcia Florencio
• Sista Srinivas Prasad

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

• F21K9/60

  Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction · CPC title

• F21V9/30

  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 title

• C09K11/616 Primary

  with alkali or alkaline earth metals · CPC title