Processes for preparing color stable red-emitting phosphor particles having small particle size

Patent metadata

Field	Value
Publication number	US-12528985-B2
Application number	US-202418611080-A
Country	US
Kind code	B2
Filing date	Mar 20, 2024
Priority date	Dec 13, 2016
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

A process for preparing a Mn +4 doped phosphor of formula I A x [MF y ]:Mn +4 I includes combining a first solution comprising a source of A and a second solution comprising H 2 MF 6 in the presence of a source of Mn, 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, 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 a value of a Hammett acidity function of the first solution is at least −0.9. Particles produced by the process may have a particle size distribution with a D 50 particle size of less than 10 μm.

First claim

The invention claimed is:

1 . A Mn +4 doped phosphor of formula I

A
x

[

MF
y

]

:

Mn

+
4

I

the phosphor comprising a monodisperse population of particles having a particle size distribution comprising a D50 particle size of less than about 10 μm;
wherein A is Li, Na, K, Rb, Cs, or a combination thereof;
M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof;
x is an absolute value of a charge of the [MF y ] ion;
y is 5, 6 or 7; and
wherein the phosphor has a quantum efficiency of greater than 85% under blue excitation.

2 . The Mn +4 doped phosphor according to claim 1 , wherein the phosphor has an aspect ratio of a plurality of particles of the monodisperse population of less than or equal to 3/1.

3 . The Mn +4 doped phosphor according to claim 1 , wherein the phosphor has an amount of manganese from about 1.2 mol % to about 21 mol %.

4 . The Mn +4 doped phosphor according to claim 1 , wherein a span of the particle size distribution is less than 1.1.

5 . The Mn +4 doped phosphor according to claim 1 , wherein the phosphor is coated with a manganese-free shell.

6 . The Mn +4 doped phosphor according to claim 5 , wherein the manganese-free shell comprises a metal fluoride.

7 . The Mn +4 doped phosphor according to claim 5 , wherein the manganese-free shell is disposed on the phosphor.

8 . The Mn +4 doped phosphor according to claim 6 , wherein the metal fluoride is KMgF 3 .

9 . The Mn +4 doped phosphor according to claim 1 , wherein M is Si and A is Na or K.

10 . The Mn +4 doped phosphor according to claim 1 , wherein the phosphor comprises a D50 particle size from 5 μm to 8 μm.

11 . A Mn +4 doped phosphor of formula I

A
x

[

MF
y

]

:

Mn

+
4

I

the phosphor comprising a monodisperse population of particles having a particle size distribution comprising a D50 particle size of less than about 10 μm,
wherein the phosphor is coated with a manganese-free shell,
wherein A is Li, Na, K, Rb, Cs, or a combination thereof;
M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof;
x is an absolute value of a charge of the [MF y ] ion;
y is 5, 6 or 7.

12 . The Mn +4 doped phosphor according to claim 11 , wherein the manganese-free shell comprises a metal fluoride.

13 . The Mn +4 doped phosphor according to claim 12 , wherein the metal fluoride is KMgF 3 .

14 . The Mn +4 doped phosphor according to claim 11 , wherein the phosphor has an aspect ratio of a plurality of particles of the monodisperse population of less than or equal to 3/1.

15 . The Mn +4 doped phosphor according to claim 11 , wherein the phosphor has an amount of manganese from about 1.2 mol % to about 21 mol %.

16 . The Mn +4 doped phosphor according to claim 11 , wherein a span of the particle size distribution is less than 1.1.

17 . The Mn +4 doped phosphor according to claim 11 , wherein the manganese-free shell is disposed on the phosphor.

18 . The Mn +4 doped phosphor according to claim 11 , wherein M is Si and A is Na or K.

19 . The Mn +4 doped phosphor according to claim 11 , wherein the phosphor has a quantum efficiency of greater than 85% under blue excitation.

20 . The Mn +4 doped phosphor according to claim 11 , wherein the phosphor comprises a D50 particle size from 5 μm to 8 μm.

21 . A phosphor composition comprising the Mn +4 doped phosphor according to claim 1 and further comprising one or more materials selected from the group consisting of other phosphors, quantum dot materials, scattering particles, electroluminescent polymers and dyes.

22 . The phosphor composition according to claim 21 , wherein the Mn +4 doped phosphor has an aspect ratio of a plurality of particles of the monodisperse population of less than or equal to 3/1.

23 . The phosphor composition according to claim 21 , wherein the M n+4 doped phosphor has an amount of manganese from about 1.2 mol % to about 21 mol %.

24 . The phosphor composition according to claim 21 , wherein a span of the particle size distribution is less than 1.1.

25 . The phosphor composition according to claim 21 , wherein the Mn +4 doped phosphor is coated with a manganese-free shell.

26 . The phosphor composition according to claim 25 , wherein the manganese-free shell comprises a metal fluoride.

27 . The phosphor composition according to claim 25 , wherein the manganese-free shell is disposed on the Mn +4 doped phosphor.

28 . The phosphor composition according to claim 26 , wherein the metal fluoride is KMgF 3 .

29 . The phosphor composition according to claim 21 , wherein M is Si and A is Na or K.

30 . The phosphor composition according to claim 21 , wherein the Mn +4 doped phosphor has a quantum efficiency of greater than 85% under blue excitation.

31 . The phosphor composition according to claim 21 , wherein the other phosphors comprise β-SiAlON or a yellow phosphor.

32 . The phosphor composition according to claim 21 , wherein the one or more materials comprises quantum dots.

33 . A silicone slurry composition comprising an Mn +4 doped phosphor of formula I suspended in the slurry,

A
x

[

MF
y

]

:

Mn

+
4

Assignees

• Current Lighting Solutions Llc

Inventors

• Murphy James Edward
• Sista Srinivas Prasad
• Camardello Samuel Joseph

Classifications

• H10H20/8506

  Containers · CPC title

• H10H20/857

  Interconnections, e.g. lead-frames, bond wires or solder balls · CPC title

• H10H20/856

  Reflecting means · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title

• C09K11/616 Primary

  with alkali or alkaline earth metals · CPC title