Fluorescent substance containing nitrogen, method for manufacturing the same, and light-emitting device

• US 7,414,272 B2
• Filed: 07/13/2005
• Issued: 08/19/2008
• Est. Priority Date: 07/14/2004
• Status: Active Grant

• Current Assignee: Toshiba Lighting & Technology Corporation (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Lighting & Technology Corporation (Toshiba Corporation), Toshiba Materials Company Limited (Toshiba Corporation)
• Inventors: Tamatani, Masaaki, Hiramatsu, Ryosuke, Shida, Naomi, Ootsuka, Kazuaki, Tsutsui, Yoshihito, Uetake, Hisayo
• Primary Examiner(s): NGUYEN, CUONG QUANG
• Application Number:
  US11/179,575
• Publication Number:
  US 20060011936A1
• Time in Patent Office: 1,133 Days
• Field of Search: 257 87-103
• US Class Current: 257/99
• CPC Class Codes: C01B 21/0602 with two or more other elements chosen from metals, silicon or boron
• CPC Class Codes: C01P 2002/54 one element only
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77217 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Disclosed is a method for manufacturing a nitrogen-containing fluorescent substance comprising accommodating an oxide fluorescent substance containing two or more elements in a receptacle made of a material containing carbon, and sintering the oxide fluorescent substance in a mixed gas atmosphere containing nitrogen gas.

Claims

1. A method for manufacturing a nitrogen-containing fluorescent substance comprising:

accommodating an oxide fluorescent substance comprising two or more metal elements in a receptacle made of a material comprising carbon; and

sintering the oxide fluorescent substance accommodated in the receptacle made of a material comprising carbon in a mixed gas atmosphere comprising nitrogen gas to produce a nitrogen-containing fluorescent substance.

2. The method according to claim 1, wherein the receptacle comprises silicon carbide.

3. The method according to claim 1, wherein the mixed gas atmosphere is a reducing mixed gas atmosphere.

4. The method according to claim 1, wherein the mixed gas atmosphere further comprises hydrogen gas.

5. The method according to claim 4, wherein the mixing ratio of the hydrogen gas to the nitrogen gas (H₂:

N₂) is 10;

90-70;

30.

6. The method according to claim 1, wherein the oxide fluorescent substance has a composition represented by the following general formula (1):

M₂SiO₄;

Z 

 

(1)

(wherein M is at least one selected from the group consisting of Sr, Ba and Ca; and

Z is at least one activator selected from the group consisting of Eu and Ce).

7. The method according to claim 1, wherein the nitrogen-containing fluorescent substance has a composition represented by the following general formula (2):

M₂Si₅N₈;

Z 

 

(2)

(wherein M is at least one selected from the group consisting of Sr, Ba and Ca; and

Z is at least one activator selected from the group consisting of Eu and Ce).

8. The method according to claim 1, wherein the sintering is performed for 2 to 10 hours at a temperature of 1600°

C. or more.

9. The method according to claim 1, wherein the sintering is performed at first for 1 to 3 hours at a temperature ranging from 800°

C. to 1400°

C. and then for 1 to 9 hours at a temperature of 1600°

C. or more.

10. The method according to claim 1, wherein the receptacle material comprises silicon carbide and carbon.

11. The method according to claim 1, wherein the receptacle material consists of silicon carbide.

12. The method according to claim 1, wherein the receptacle material consists of carbon.

13. A method for manufacturing a nitrogen-containing fluorescent substance comprising:

sintering an oxide fluorescent substance represented by the following general formula (1) in a mixed gas atmosphere containing nitrogen gas, thereby converting at least part of the oxide fluorescent substance into a nitrogen-containing fluorescent substance represented by the following general formula (2);

M₂SiO₄;

Z 

 

(1)

M₂Si₅N₈;

Z 

 

(2)

(wherein M is at least one selected from the group consisting of Sr, Ba and Ca; and

Z is at least one activator selected from the group consisting of Eu and Ce).

14. The method according to claim 13, further comprising accommodating the oxide fluorescent substance in a receptacle made of a material containing carbon before sintering the oxide fluorescent substance.

15. The method according to claim 14, wherein the receptacle comprises silicon carbide or carbon.

16. The method according to claim 13, wherein the mixed gas atmosphere is a reducing mixed gas atmosphere.

17. The method according to claim 13, wherein the mixed gas atmosphere is an atmosphere containing hydrogen gas.

18. The method according to claim 17, wherein the mixing ratio of the hydrogen gas to the nitrogen gas (H₂:

N₂) is 10;

90-70;

30.

19. The method according to claim 13, wherein the sintering is performed for 2 to 10 hours at a temperature of 1600°

C. or more.