Color stable red-emitting phosphors

Patent metadata

Field	Value
Publication number	US-9580648-B2
Application number	US-201414285746-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	Mar 15, 2013
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A color stable Mn4+ doped phosphor of formula I,

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; and
wherein % intensity loss of the phosphor after exposure to light flux of at least 80 w/cm 2 at a temperature of at least 50° C. for at least 21 hours is ≦4%.

First claim

The invention claimed is:

1. A process for synthesizing a Mn 4+ doped phosphor, the process comprising contacting a precursor at an elevated temperature with a fluorine-containing oxidizing agent in gaseous form, 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) 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;
(F) Ba 0.65 Zr 0.35 F 2.70 : Mn 4+ ; and
(G) A 3 [ZrF 7 ]: Mn 4+ where A is selected from Li, Na, K, Rb, Cs and combinations thereof.

2. A process according to claim 1 , wherein the elevated temperature is any temperature in a range from about 500° C. to about 600° C.

Assignees

• Gen Electric

Inventors

• Murphy James Edward
• Setlur Anant Achyut
• Garcia Florencio
• Lyons Robert Joseph
• Chowdhury Ashfaqul Islam
• Karkada Nagaveni
• Nammalwar Prasanth Kumar

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

• C09K11/616 Primary

  with alkali or alkaline earth metals · CPC title

• H01L33/502

  Electricity · mapped topic

• H10H20/8512

  Wavelength conversion materials · CPC title