(Oxy)nitride phosphor powder and method of producing same

Patent metadata

Field	Value
Publication number	US-9828545-B2
Application number	US-201414781132-A
Country	US
Kind code	B2
Filing date	Mar 28, 2014
Priority date	Mar 29, 2013
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

An (oxy)nitride phosphor powder has a fluorescence peak wavelength of 610 to 625 nm and also has higher external quantum efficiency than the conventional one. The (oxy)nitride phosphor powder includes an α-type SiAlON and aluminum nitride, represented by the compositional formula: Ca x1 Eu x2 Si 12−(y+z) Al (y+z) O z N 16−z wherein x1, x2, y, z fulfill the following formulae: 1.60≦x1+x2≦2.90, 0.18≦x2/x1≦0.70, 4.0≦y≦6.5, 0.0≦z≦1.0. The powder can additionally contain Li in an amount of 50 to 10000 ppm. The content of the aluminum nitride may be more than 0 mass % to less than 33 mass %.

First claim

The invention claimed is:

1. An (oxy)nitride phosphor powder containing an α-SiAlON crystal phase and aluminum nitride crystal phase, represented by the composition formula:
Ca x1 Eu x2 Si 12−(y+z) Al (y+z) O z N 16−z

wherein x1, x2, y and z are 1.60≦x1+x2≦2.90, 0.18≦x2/x1≦0.70, 4.0≦y≦6.5 and 0.0≦z≦1.0.

2. The (oxy)nitride phosphor powder according to claim 1 , wherein the content of aluminum nitride crystal phase is from more than 0 mass % to less than 33 mass %.

3. The (oxy)nitride phosphor powder according to claim 1 , further containing from 50 to 10,000 ppm of Li.

4. The (oxy)nitride phosphor powder according to claim 1 , wherein a fluorescence having a peak wavelength in a wavelength region of 610 to 625 nm is emitted by excitation with light having a wavelength of 450 nm and an external quantum efficiency in the light emission is 50% or more.

5. The (oxy)nitride phosphor powder according to claim 1 , wherein a 50% diameter (D 50 ) in a particle size distribution curve measured by a laser diffraction/scattering particle size distribution measuring apparatus is 10.0 to 20.0 μm and specific surface area is 0.2 to 0.6 m 2 /g.

6. A method of producing the (oxy)nitride phosphor powder according to claim 1 , comprising:
a first step of mixing a silicon source substance, an aluminum source substance, a calcium source substance, and a europium source substance to provide a composition represented by the composition formula:
Ca x1 Eu x2 Si 12−(y+z) Al (y+z) O z N 16−z

wherein x1, x2, y and z are
1.60≦x1+x2≦2.90,
0.18≦x2/x1≦0.70,
4.0≦y≦6.5,
0.0≦z≦1.0, followed by firing at a temperature of 1,500 to 2,000° C. in an inert gas atmosphere to obtain a fired (oxy)nitride represented by the formula above, and
a second step of heat-treating the fired (oxy)nitride, wherein the heat treatment in the second step is performed at a temperature of 1,100 to 1,600° C. in an inert gas atmosphere or a reducing atmosphere.

7. A method of producing the (oxy)nitride phosphor powder according to claim 1 , comprising:
a first step of mixing a silicon source substance, an aluminum source substance, a calcium source substance, and a europium source substance to provide a composition represented by the composition formula:
Ca x1 Eu x2 Si 12−(y+z) Al (y+z) O z N 16−z

wherein x1, x2, y and z are
1.60≦x1+x2≦2.90,
0.18≦x2/x1≦0.70,
4.0≦y≦6.5,
0.0≦z≦1.0, followed by firing at a temperature of 1,500 to 2,000° C. in an inert gas atmosphere to obtain a fired (oxy)nitride represented by the formula above, and
a second step of heat-treating the fired (oxy)nitride, wherein the heat treatment in the second step is performed in the presence of Li at a temperature of 1,450° C. to less than the firing temperature in an inert gas atmosphere or a reducing atmosphere.

8. The method according to claim 6 , wherein the silicon source substance is a silicon nitride powder and the silicon nitride powder has an oxygen content of 0.2 to 0.9 mass %, an average particle size of 1.0 to 12.0 μm and a specific surface area of 0.2 to 3.0 m 2 /g.

9. The method according to claim 7 , wherein the silicon source substance is a silicon nitride powder and the silicon nitride powder has an oxygen content of 0.2 to 0.9 mass %, an average particle size of 1.0 to 12.0 μm and a specific surface area of 0.2 to 3.0 m 2 /g.

Assignees

• Ube Industries
• Ube Industries

Inventors

• Sumino Mao
• Iwashita Kazuki
• Sakai Takuma
• Fujinaga Masataka
• Jida Shinsuke

Classifications

• C09K11/77348 Primary

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• C01B21/06 Primary

  Binary compounds of nitrogen with metals, with silicon, or with boron, {or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron}(azides C01B21/08) · CPC title

• C09K11/7734 Primary

  Aluminates · CPC title