Method of producing nitride fluorescent material

• US 10,563,124 B2
• Filed: 06/28/2017
• Issued: 02/18/2020
• Est. Priority Date: 06/30/2016
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Hosokawa, Shoji, Kuramoto, Daiki
• Primary Examiner(s): Koslow, C Melissa
• Application Number:
  US15/635,751
• Publication Number:
  US 20180002600A1
• Time in Patent Office: 965 Days
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides

Abstract

A method of producing a nitride fluorescent material having relatively high light emission intensity is provided. The method of producing a nitride fluorescent material includes preparing a calcined product having a composition containing at least one first element selected from the group consisting of Ba, Sr, Ca, and Mg, at least one second element selected from the group consisting of Eu, Ce, Tb, and Mn, and Si and N, and bringing the calcined product into contact with a fluorine-containing substance at a temperature in a range of −20° C. or higher and lower than 150° C.

Claims

1. A method of producing a nitride fluorescent material, comprising:

preparing a calcined product having a composition that contains at least one first element selected from the group consisting of Ba, Sr, Ca, and Mg, at least one second element selected from the group consisting of Eu, Ce, Tb, and Mn, and Si and N, and

bringing the calcined product into contact with a fluorine-containing substance at a temperature in a range of −

20°

C. or higher and lower than 150°

C.,

wherein the fluorine-containing substance is at least one fluorine-based gas selected from the group consisting of F₂, CHF₃, CF₄, SiF₄, and NF₃.

2. The method of producing a nitride fluorescent material according to claim 1, wherein the at least one first element includes Ba.

3. The method of producing a nitride fluorescent material according to claim 1, wherein the temperature at which the calcined product is brought into contact with the fluorine-containing substance is at a temperature in a range of 0°

C. or higher and lower than 140°

C.

4. The method of producing a nitride fluorescent material according to claim 1, wherein the fluorine content in the nitride fluorescent material is in a range of 1% by mass or more and 10% by mass or less.

5. The method of producing a nitride fluorescent material according to claim 1, wherein the calcined product has a composition represented by the following formula (I):

(M1<sub>1−

y</sub>M2_y)₂Si₅N₈ 

 

(I)

wherein M1 represents at least one element selected from the group consisting of Ba, Sr, Ca, and Mg, M2 represents at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and y is a number satisfying 0.001≤

y<

0.5.

6. The method of producing a nitride fluorescent material according to claim 1, wherein the calcined product has a composition represented by the following formula (II):

(Ba<sub>1−

x−

y</sub>M12_xM2_y)₂Si₅N₈ 

 

(II)

wherein M12 represents at least one element selected from the group consisting of Sr, Ca and Mg, M2 represents at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and x and y each are numbers satisfying 0.0≤

x<

1.0, 0.001≤

y<

0.5, and 0.001≤

x+y<

1.0.

7. The method of producing a nitride fluorescent material according to claim 1, wherein the calcined product is brought into contact with the fluorine-containing substance in an inert gas atmosphere.

8. The method of producing a nitride fluorescent material according to claim 1, wherein the fluorine-containing substance is fluorine gas.

9. The method of producing a nitride fluorescent material according to claim 1, wherein a reflectance at wavelength 450 nm of the nitride fluorescent material is 12% or less.

10. A method of producing a nitride fluorescent material, comprising:

preparing a calcined product having a composition that contains at least one first element selected from the group consisting of Ba, Sr, Ca, and Mg, at least one second element selected from the group consisting of Eu, Ce, Tb, and Mn, and Si and N, and

bringing the calcined product into contact with a fluorine-containing substance at a temperature in a range of −

20°

C. or higher and lower than 150°

C.,

wherein the calcined product is brought into contact with the fluorine-containing substance in an inert gas atmosphere.

11. The method of producing a nitride fluorescent material according to claim 10, wherein the at least one first element includes Ba.

12. The method of producing a nitride fluorescent material according to claim 10, wherein the temperature at which the calcined product is brought into contact with the fluorine-containing substance is at a temperature in a range of 0°

C. or higher and lower than 140°

C.

13. The method of producing a nitride fluorescent material according to claim 10, wherein the fluorine content in the nitride fluorescent material is in a range of 1% by mass or more and 10% by mass or less.

14. The method of producing a nitride fluorescent material according to claim 10, wherein the calcined product has a composition represented by the following formula (I):

(M1<sub>1−

y</sub>M2_y)₂Si₅N₈ 

 

(I)

wherein M1 represents at least one element selected from the group consisting of Ba, Sr, Ca, and Mg, M2 represents at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and y is a number satisfying 0.001≤

y<

0.5.

15. The method of producing a nitride fluorescent material according to claim 10, wherein the calcined product has a composition represented by the following formula (II):

(Ba<sub>1−

x−

y</sub>M12_xM2_y)₂Si₅N₈ 

 

(II)

wherein M12 represents at least one element selected from the group consisting of Sr, Ca and Mg, M2 represents at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and x and y each are numbers satisfying 0.0≤

x<

1.0, 0.001y≤

0.5, and 0.001≤

x+y<

1.0.

16. The method of producing a nitride fluorescent material according to claim 10, wherein the fluorine-containing substance is fluorine gas.

17. The method of producing a nitride fluorescent material according to claim 10, wherein a reflectance at wavelength 450 nm of the nitride fluorescent material is 12% or less.