Oxynitride phosphor powder and method for producing same

Patent metadata

Field	Value
Publication number	US-10125313-B2
Application number	US-201515115943-A
Country	US
Kind code	B2
Filing date	Feb 2, 2015
Priority date	Feb 3, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

An oxynitride phosphor powder has a fluorescence peak wavelength of 587 to 630 nm and a high external quantum efficiency. A method of producing the oxynitride phosphor powder containing Li at 50 to 10,000 ppm includes mixing silicon nitride powder, a substance serving as an aluminum source, a substance serving as a calcium source and a substance serving as an europium source; firing the mixture at 1500 to 2000° C. in an inert gas atmosphere or a reducing gas atmosphere to obtain a fired oxynitride phosphor composed mainly of Ca-containing α-SiAlON, as an intermediate; and heat treating the fired oxynitride phosphor at a temperature of 1450° C. to less than the firing temperature, in an inert gas atmosphere or in a reducing gas atmosphere in the presence of Li.

First claim

What is claimed is:

1. A method of producing an oxynitride phosphor powder containing Li at 50 to 10,000 ppm, comprising:
mixing silicon nitride powder, a substance serving as an aluminum source, a substance serving as a calcium source and a substance serving as an europium source to form a mixture;
firing the mixture at 1500 to 2000° C. in an inert gas atmosphere or in a reducing gas atmosphere to obtain a fired oxynitride phosphor composed mainly of Ca-containing α-SiAlON not containing Li, as an intermediate; and
heat treating the fired oxynitride phosphor at a temperature of 1450° C. to less than the firing temperature, in an inert gas atmosphere or in a reducing gas atmosphere in the presence of Li.

2. An oxynitride phosphor powder obtained by mixing silicon nitride powder, a substance serving as an aluminum source, a substance serving as a calcium source and a substance serving as an europium source to form a mixture, firing the mixture at 1500 to 2000° C. in an inert gas atmosphere or in a reducing gas atmosphere to obtain a fired oxynitride phosphor composed mainly of Ca-containing α-SiAlON not containing Li, as an intermediate, and heat treating the fired oxynitride phosphor at a temperature of 1450° C. to less than the firing temperature, in an inert gas atmosphere or in a reducing gas atmosphere in the presence of Li, the powder containing 50 to 10,000 ppm of Li and having a surface Li content of 50% or greater.

3. An oxynitride phosphor powder comprising Ca-containing α-SiAlON and aluminum nitride, and 50 to 10,000 ppm of Li and having a surface Li content of 50% or greater.

4. The oxynitride phosphor powder according to claim 3 , wherein a compositional formula of the Ca-containing α-SiAlON and aluminum nitride is as follows:
Ca x1 EU x2 Si 12−(y+z) Al (y+z) O z N 16−z

wherein 1.60≤x1+x2≤3.00, 0.10≤x2/x1≤1.20, 4.0≤y≤7.0, 0≤z≤0.5.

5. The oxynitride phosphor powder according to claim 4 , wherein the aluminum nitride content is greater than 0 mass % and less than 36 mass %.

6. The oxynitride phosphor powder according to claim 4 , wherein excitation with light having a wavelength of 450 nm causes emission of fluorescence with a peak wavelength in a wavelength range of 605 nm to 630 nm, an external quantum efficiency thereof being 50% or greater.

7. The oxynitride phosphor powder according to claim 3 , wherein the aluminum nitride content is greater than 0 mass % and less than 36 mass %.

8. The oxynitride phosphor powder according to claim 7 , wherein excitation with light having a wavelength of 450 nm causes emission of fluorescence with a peak wavelength in a wavelength range of 605 nm to 630 nm, an external quantum efficiency thereof being 50% or greater.

9. The oxynitride phosphor powder according to claim 3 , wherein excitation with light having a wavelength of 450 nm causes emission of fluorescence with a peak wavelength in a wavelength range of 605 nm to 630 nm, an external quantum efficiency thereof being 50% or greater.

10. An oxynitride phosphor powder obtained by mixing silicon nitride powder, a substance serving as an aluminum source, a substance serving as a calcium source and a substance serving as an europium source to form a mixture, firing the mixture at 1500 to 2000° C. in an inert gas atmosphere or in a reducing gas atmosphere to obtain a fired oxynitride phosphor comprising Ca-containing α-SiAlON not containing Li and aluminum nitride, as an intermediate, and heat treating the fired oxynitride phosphor at a temperature of 1450° C. to less than the firing temperature, in an inert gas atmosphere or in a reducing gas atmosphere in the presence of Li, the powder containing 50 to 10,000 ppm of Li and having a surface Li content of 50% or greater.

11. A light-emitting device employing the oxynitride phosphor powder according to claim 10 .

12. A light-emitting device employing the oxynitride phosphor powder according to claim 3 .

13. A light-emitting device employing the oxynitride phosphor powder according to claim 4 .

14. A light-emitting device employing the oxynitride phosphor powder according to claim 7 .

15. A light-emitting device employing the oxynitride phosphor powder according to claim 9 .

16. A light-emitting device employing the oxynitride phosphor powder according to claim 10 .

Assignees

• Ube Industries

Inventors

• Sumino Mao
• Ueda Takayuki
• Iwashita Kazuki
• Fujinaga Masataka
• Jida Shinsuke

Classifications

• C09K11/0883

  Arsenides; Nitrides; Phosphides · CPC title

• C09K11/55 Primary

  containing beryllium, magnesium, alkali metals or alkaline earth metals · CPC title

• C09K11/77348 Primary

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• C09K11/7734 Primary

  Aluminates · CPC title

• H01L33/502

  Electricity · mapped topic