Process for preparing red-emitting phosphors

Patent metadata

Field	Value
Publication number	US-9546318-B2
Application number	US-201414267449-A
Country	US
Kind code	B2
Filing date	May 1, 2014
Priority date	May 1, 2014
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A process for preparing a Mn 4+ doped phosphor of formula I

A x [MF y ]:Mn +4   I

includes contacting a mixture of a compound of formula A x [MF y ], a compound of formula AX, and a Mn +n source comprising a fluoromanganese compound, with a fluorine-containing oxidizing agent in gaseous form, at an elevated temperature, to form the Mn 4+ doped phosphor;

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 F, Cl, Br, I, HF 2 , or a combination thereof; x is the absolute value of the charge of the [MF y ] ion; y is 5, 6 or 7; and n is 2, 3, or 4.

First claim

The invention claimed is:

1. A process for preparing a Mn 4+ doped phosphor of formula I,
A x [MF y ]:Mn +4    I

the process comprising contacting a mixture of a compound of formula A x [MF y ], a compound of formula AX, and a Mn +n source comprising a fluoromanganese compound, with a fluorine-containing oxidizing agent in gaseous form, at an elevated temperature, to form the Mn 4+ doped phosphor; 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 F, Cl, Br, I, HF 2 , 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; and
n is 2, 3, or 4.

2. A process according to claim 1 , wherein the Mn 4+ doped phosphor is K 2 SiF 6 :Mn 4+ .

3. A process according to claim 1 , wherein the compound of formula A x [MF y ] is K 2 SiF 6 .

4. A process according to claim 1 , wherein the compound of formula AX is KF, KHF 2 , or a combination thereof.

5. A process according to claim 1 , wherein the Mn +n source is selected from K 2 MnF 6 , K 2 MnF 5 .H 2 O, KMnF 4 , K 2 MnF 4 , KMnF 3 , MnF 2 , MnF 3 , MnF 4 , and combinations thereof.

6. A process according to claim 1 , wherein the Mn +n source is K 2 MnF 6 , MnF 2 , MnF 3 , or a combination thereof.

7. A process according to claim 1 , wherein the fluorine-containing oxidizing agent is F 2 .

8. A process according to claim 1 , additionally comprising treating the phosphor in particulate form with a saturated solution of a composition of formula II in aqueous hydrofluoric acid, after contacting with the fluorine-containing oxidizing agent
A x [MF y ]   II.

9. A process for preparing a Mn 4+ doped phosphor, the process comprising contacting a mixture of a host compound of the phosphor, a compound of formula AX or EX 2 , and a Mn +n source comprising a fluoromanganese compound; with a fluorine-containing oxidizing agent in gaseous form, at an elevated temperature, to form the Mn 4+ doped phosphor;
wherein the host compound is selected from the group consisting of
(a) A 2 [MF 5 ], where M is selected from Al, Ga, In, and combinations thereof;
(b) A 3 [MF 6 ], where M is selected from Al, Ga, In, and combinations thereof;
(c) Zn 2 [MF 7 ], where M is selected from Al, Ga, In, and combinations thereof;
(d) A[In 2 F 7 ];
(e) A 2 [MF 6 ], where M is selected from Ge, Si, Sn, Ti, Zr, and combinations thereof;
(f) E[MF 6 ], 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 ; and
(h) A 3 [ZrF 7 ]; and combinations thereof in solid solution;
A is Li, Na, K, Rb, Cs, or a combination thereof.

10. A process according to claim 9 , wherein the fluorine-containing oxidizing agent is F 2 .

11. A process for preparing a Mn 4+ doped phosphor of formula I,
A x [MF y ]:Mn +4    I

the process comprising contacting a mixture of a phosphor precursor and a flux compound selected from compounds of formula AX, EX 2 , MF 2 , or MF 3 , or a combination thereof, with a fluorine-containing oxidizing agent in gaseous form at an elevated temperature, to form the Mn 4+ doped phosphor;

wherein
A is Li, Na, K, Rb, Cs, or a combination thereof;
E is Mg, Ca, Sr, Ba, Zn, and combinations 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 F, CI, Br, I, HF 2 ,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; and
y is 5, 6 or 7.

12. A process according to claim 11 , wherein the flux compound is of formula AX.

13. A process according to claim 12 , wherein the compound of formula AX is KF, KHF 2 , or a combination thereof.

Assignees

• Gen Electric

Inventors

• Murphy James Edward
• Lyons Robert Joseph
• Setlur Jr Anant Achyut

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

• C09K11/77

  containing rare earth metals · CPC title

• C09K11/617 Primary

  Silicates · CPC title

• C09K11/616

  with alkali or alkaline earth metals · CPC title