Phosphor and manufacturing method for the same, and light source

• US 7,476,338 B2
• Filed: 08/26/2005
• Issued: 01/13/2009
• Est. Priority Date: 08/27/2004
• Status: Active Grant

• Current Assignee: Citizen Electronics Company Limited
• Original Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited), Nichia Corporation
• Inventors: Gotoh, Masahiro, Nagatomi, Akira, Yamashita, Shuji, Sakane, Kenji, Ikuta, Tetsuya
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US11/211,751
• Publication Number:
  US 20060065878A1
• Time in Patent Office: 1,236 Days
• Field of Search: 252/301.4 F, 252/301.4 H, 252/301.6 F, 313/503, 257/98
• US Class Current: 252/301.40F
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

To provide a phosphor having an emission spectrum with a broad peak in a range from yellow color to red color (580 nm to 680 nm) and an excellent excitation band on the longer wavelength side from near ultraviolet/ultraviolet of excitation light to visible light (250 nm to 550 nm), and having an improved emission intensity. The phosphor is provided, which is given by a general composition formula expressed by MmAaBbOoNn:Z, (wherein element M is more than one kind of element having bivalent valency, element A is more than one kind of element having tervalent valency selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, element B is more than one kind of element having tetravalent valency, O is oxygen, N is nitrogen, and element Z is more than one kind of element selected from rare earth elements or transitional metal elements, satisfying m>0, a>0, b>0 o≧0, and n=2/3m+a+4/3b−2/3o), and further containing boron and/or fluorine.

Claims

1. A phosphor, which is given by a general composition formula expressed by MmAaDbOoNn:

Z, (wherein element M is at least one kind of element having bivalent valency, element A is at least one kind of element having tervalent valency selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, element D is at least one kind of element having tetravalent valency, O is oxygen, N is nitrogen, and element Z is at least one kind of element selected from rare earth elements or transitional metal elements, expressed by m=a=b=1, and n=2/3M+a+4/3b−

2/3o), and further containing boron and/or fluorine

wherein a content of the boron not less than 0.001 wt % and not more than 3.0 wt %.

2. The phosphor according to claim 1, wherein o=0.

3. The phosphor according to claim 1, wherein the element M is at least one kind of element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, the element A is at least one kind of element selected from the group consisting of Al and Ga, the element D is Si and/or Ge, and the element Z is at least one kind of element selected from the rare earth elements and the transitional metal elements.

4. The phosphor according to claim 1, wherein the element M is Ca, the element A is Al, the element D is Si, and the element Z is Eu.

5. The phosphor according to claim 1, wherein the content of the element Fe is smaller than 200 ppm.

6. The phosphor according to claim 1, wherein the phosphor is in a powdery state.

7. The phosphor according to claim 6, wherein an average particle size of the phosphor is not more than 20 μ

m and not less than 0.1 μ

m.

8. The phosphor according to claim 6, wherein a specific surface area of the phosphor powder is not more than 50 m²/g and not less than 0.1 m²/g.

9. A phosphor, which is given by a general composition formula expressed by MmAaDbOoNn:

Z, (wherein element M is at least one kind of element having bivalent valency, element A is at least one kind of element having tervalent valency selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, element D is at least one kind of element having tetravalent valency, O is oxygen, N is nitrogen, and element Z is at least one kind of element selected from rare earth elements or transitional metal elements, expressed by m=a=b=1, and n=2/3M+a+4/3b−

2/3o), and further containing boron and/or fluorine

wherein the content of the fluorine is not less than 0.1 wt % and not more than 3.0 wt %.

10. The phosphor according to claim 9, wherein o=0.

11. The phosphor according to claim 9, wherein the element M is at least one kind of element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn, the element A is at least one kind of element selected from the group consisting of Al and Ga, the element D is Si and/or Ge, and the element Z is at least one kind of element selected from the rare earth elements and the transitional metal elements.

12. The phosphor according to claim 9, wherein the element M is Ca, the element A is Al, the element D is Si, and the element Z is Eu.

13. The phosphor according to claim 9, wherein the content of the element Fe is smaller than 200 ppm.

14. The phosphor according to claim 9, wherein the phosphor is in a powdery state.

15. A manufacturing method of a phosphor,

the phosphor containing a phosphor crystal which is given by a general composition formula expressed by MmAaDbOoNn:

Z, (wherein element M is at least one kind of element having bivalent valency, element A is at least one kind of element having tervalent valency selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, element D is at least one kind of element having tetravalent valency, O is oxygen, N is nitrogen, and element Z is at least one kind of element selected from rare earth elements or transitional metal elements, and further containing boron and/or fluorine expressed by m=a=b=1, and n=2/3m+a+4/3b−

2/3o),

said method comprising the steps of;

weighting and mixing the raw materials in an inert atmosphere to manufacture a mixture;

firing this mixture to manufacture a fired substance; and

pulverizing this fired substance to manufacture the phosphor,

wherein a boron compound and/or a fluorine compound are further added to a raw material of the phosphor expressed by the composition formula MmAaDbOoNn;

Z,

wherein the compound containing the element M, the compound containing the element A, the compound containing the element D, and the compound containing the element Z or a simple substance of the element Z, and the boron compound containing 100 ppm or less content of Fe and/or the fluorine compound containing 100 ppm or less content of Fe are used.

16. The manufacturing method of the phosphor according to claim 15, wherein a nitride of group II expressed by a general formula M₃N₂ containing 100 ppm or less of element Fe (wherein the element M is at least one kind of element selected from the group consisting of Mg, Ca, Sr, Ba, and Zn) is used as the compound containing the element M.

17. The manufacturing method of the phosphor according to claim 16, wherein a nitride of group II element manufactured by nitriding a simple substance of 2N or more belonging to group II element and containing 100 ppm or less Fe is used, in a nitrogen atmosphere or in an ammonia atmosphere at the temperature of 300°

C. or more.

18. The manufacturing method of the phosphor according to claim 15, wherein AlN having an average particle size of 0.1 μ

m to 5.0 μ

m is used as the compound containing the element A, and Si₃N₄ having the average particle size of 0.1 μ

m to 5.0 μ

m is used as the compound containing the element D.

19. The manufacturing method of the phosphor according to claim 15, wherein the boron compound is BN and/or H₃BO₃.

20. The manufacturing method of the phosphor according to claim 15, wherein the fluorine compound is CaF₂ and/or AlF₃.

21. The manufacturing method of the phosphor according to claim 15, wherein any one of the nitrogen atmosphere, the ammonia atmosphere, a mixed gas atmosphere of nitrogen and hydrogen, and the mixed gas atmosphere of the nitrogen and ammonia is used, in the step of obtaining a fired object by firing the mixture.

22. The manufacturing method of the phosphor according to claim 15, wherein a nitrogen gas of 80% or more concentration is used, as an atmosphere gas during firing, in the step of obtaining the fired object by firing the mixture.

23. The manufacturing method of the phosphor according to claim 15, wherein the mixture is fired while ventilating the atmosphere gas at the rate of 0.01 L/min or more, in the step of obtaining the fired object by firing the mixture.

24. The manufacturing method of the phosphor according to claim 15, wherein the temperature is set at not less than 1200°

C. and not more than 1600°

C. during firing, in the step of obtaining the fired object by firing the mixture.

25. The manufacturing method of the phosphor according to claim 15, wherein a pressurizing state of the atmosphere gas during firing is set at not less than 0.001 MPa and not more than 0.1 MPa.