IP Library Granted Patent US 7,524,437
Granted Patent B2
US 7,524,437 · App. 11/365,830 · Granted Apr 28, 2009

Phosphor and manufacturing method of the same, and light emitting device using the phosphor

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Quick Facts
Patent No.
US 7,524,437
App. No.
11/365,830
Granted
Apr 28, 2009
Kind
B2
Abstract

To provide a phosphor having an emission spectrum with a broad peak in a range from green color to yellow color, having a broad and flat excitation band capable of using lights of broad range from near ultraviolet/ultraviolet to blue lights as excitation lights, and having excellent emission efficiency and luminance. The problem is solved by providing the phosphor expressed by a general composition formula MmAaBbOoNn:Z (where element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is one or more kinds of elements acting as the activator.), satisfying 4.0<(a+b)/m<7.0, a/m≧0.5, b/a >2.5, n>o, n=2/3 m+a+4/3 b−2/3 o.

Claims (33)

1. A phosphor, which is given as a general composition formula expressed by MmAaBbOoNn:Z, (where element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is Ce acting as an activator.), satisfying 4.0<(a+b)/m<7.0,0.8≦a/m≦1.2, b/a>2.5, n>o, 4.0≦b/m≦6.0, 0<o/m≦3.0,n=2/3m+a+4/3b−2/3o,

wherein when the phosphor is irradiated with one or more kind of monochromatic light or continuous light having a wavelength range from 350 nm to 500 nm as an excitation light, a peak wavelength in an emission spectrum is in the range from 500 to 600 nm.

2. The phosphor according to claim 1 , wherein the element M is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, Ba, Zn and rare earth elements having bivalent valency, the element A is one or more kinds of elements selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, the element B is one or more kinds of elements selected from the group consisting of Si, Ge, Sn, Ti, Hf, Mo, W, Cr, Pb, Zr.

3. The phosphor according to claim 1 , wherein the element M is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, Ba, Zn, the element A is one or more kinds of elements selected from the group consisting of Al, Ga, In, the element B is Si or Ge or Si and Ge.

4. The phosphor according to claim 1 , wherein the element M is Sr, the element A is Al, the element B is Si.

5. The phosphor according to claim 1 , wherein when the general formula is expressed by MmAaBbOoNn:Zz, a value of z/(m+z), which is a molar ratio of the element M to the element Z, is 0.0001 or more and 0.5 or less.

6. The phosphor according to claim 1 , which is given as formulas expressed by: Sr 6 Al 6 Si 18 O 3 N 32 :Ce, SrAlSi 3 ON 5 :Ce, Sr 3 Al 3 Si 9 O 6 N 13 :Ce, Sr 6 Al 6 Si 24 O 3 N 40 :Ce, Sr 3 Al 3 Si 12 O 3 N 19 :Ce, Sr 3 Al 3 Si 12 O 6 N 17 :Ce, Sr 6 Al 6 Si 27 O 3 N 44 :Ce, Sr 2 Al 2 Si 9 O 2 N 14 :Ce, Sr 6 Al 6 Si 27 O 12 N 38 :Ce, Sr 2 Al 2 Si 10 ON 16 :Ce, Sr 3 Al 3 Si 15 O 3 N 23 :Ce, SrAlSi 5 O 2 N 7 :Ce, Sr 6 Al 6 Si 36 O 3 N 56 :Ce, SrAlSi 6 ON 9 :Ce,Sr 3 Al 3 Si 18 O 6 N 25 :Ce.

7. The phosphor according to claim 1 , containing Sr of 20.0 to 27.0 wt %, Al of 5.0 to 9.0 wt %, Si of 30.0 to 39.0 wt %, O of 0.5 to 6.0 wt %, N of 26.0 to 32.0 wt %, and Ce of beyond 0 to 3.5 wt %, wherein x of chromaticity (x, y) of the emission spectrum is in the range from 0.3500 to 0.4500, and y of the chromaticity (x, y) is in the range from 0.5000 to 0.6000.

8. The phosphor according to claim 1 , wherein in an X-ray powder diffraction pattern by CoKα ray, when maximum peaks are defined as a, b, and c, respectively, with Bragg angle (2θ) in a range from 28.5° to 29.5°, 35.5°to 36.5°, and 41.0° to 42.0°, and a peak intensity ratio of a to b is defined as I(a/b), and a peak intensity ratio of c to b is defined as I(c/b), a relation of a, b, c is given satisfying 0.20<I(a/b),I(c/b)<0.80.

9. The phosphor according to claim 1 , wherein when a value of relative intensity of a maximum peak in the emission spectrum is defined as P 25 when the phosphor is irradiated with a specified monochromatic light in the wavelength range from 350 nm to 550 nm as the excitation light at 25° C., and a value of relative intensity of a maximum peak is defined as P 200 when the phosphor is irradiated with the specified monochromatic light as the excitation light at 200° C., a relation of P 25 and P 200 is given satisfying (P 25 −P 200 ) / P 25 ×100≦35.

10. The phosphor according to claim 1 , wherein the phosphor is a powdery form.

11. The phosphor according to claim 10 , containing a primary particle with particle size of 20μm or less and aggregates in which the primary particle agglutinates, wherein an average particle size (D50) of the powdery phosphor containing the primary particle and the aggregates is 1.0 μm or more and 20.0 μm or less.

12. A method of manufacturing the phosphor according to claim 1 , wherein by using a crucible composed of nitride as a firing crucible, raw materials are fired at temperature of 1400° C. or more and 2000° C. or less in an atmosphere containing one or more kind of gas selected from nitrogen gas, rare gas, and ammonia gas.

13. The method of manufacturing the phosphor according to claim 12 , wherein the raw materials are fired by setting pressure inside furnace at 0.5MPa or less.

14. ) The method of manufacturing the phosphor according to claim 12 , wherein the crucible composed of nitride is a BN crucible.

15. The method of manufacturing the phosphor according to claim 12 , wherein the raw materials are fired, with 0.1 ml/min or more gas containing one or more kind of gas selected from the nitrogen gas, rare gas, and the ammonia gas flowing inside the furnace.

16. The method of manufacturing the phosphor according to claim 12 , wherein the raw materials are fired in a powdery state.

17. An emission device, having the phosphor according to claim 11 , and an emission part emitting light of a first wavelength, wherein the light with the wavelength different from the first wavelength is emitted from the phosphor, with a part of or the whole part of the light of the first wavelength as an excitation light.

18. The emission device according to claim 17 , wherein the first wavelength is in a range from 350 nm to 550 nm.

19. The emission device according to claim 17 , wherein the emission part emitting the first wavelength is an LED.

20. A phosphor, which is given as a general composition formula expressed by MmAaBbOoNn:Z, (where element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is Eu acting as an activator.), satisfying 4.0<(a+b)/m<7.0,0 8≦a/m≦1.2,b/a>2.5,n>o,4.0≦b/m≦6.0,0<o/m≦3.0,n=2/3m+a+4/3b−2/3o,

wherein when the phosphor is irradiated with one or more kind of monochromatic light or continuous light having a wavelength range from 350 nm to 500 nm as an excitation light, a peak wavelength of an emission spectrum is in the range from 550 to 650 nm.

21. The phosphor according to claim 20 , wherein the element M is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, Ba, Zn and rare earth elements having bivalent valency, the element A is one or more kinds of elements selected from the group consisting of Al, Ga, In, Tl, Y, Sc, P, As, Sb, and Bi, the element B is one or more kinds of elements selected from the group consisting of Si, Ge, Sn, Ti, Hf, Mo, W, Cr, Pb, Zr.

22. The phosphor according to claim 20 , wherein the element M is one or more kinds of elements selected from the group consisting of Mg, Ca, Sr, Ba, Zn, the element A is one or more kinds of elements selected from the group consisting of Al, Ga, In, the element B is Si or Ge or Si and Ge.

23. The phosphor according to claim 20 , wherein the element M is Sr, the element A is Al, the element B is Si.

24. The phosphor according to claim 20 , wherein when the general formula is expressed by MmAaBbOoNn:Zz, a value of z/(m+z), which is a molar ratio of the element M to the element Z, is 0.0001 or more and 0.5 or less.

25. The phosphor according to claim 20 , which is given as formulas expressed by: Sr 6 Al 6 Si 18 O 3 N 32 :Eu, SrAlSi 3 ON 5 :Eu, Sr 3 Al 3 Si 9 O 6 N 13 :Eu, Sr 6 Al 6 Si 24 O 3 N 40 :Eu, Sr 3 Al 3 Si 12 O 3 N 19 :Eu, Sr 3 Al 3 Si 12 O 6 N 17 :Eu, Sr 6 Al 6 Si 27 O 3 N 44 :Eu, Sr 2 Al 2 Si 9 O 2 N 14 :Eu, Sr 6 Al 6 Si 27 O 12 N 38 :Eu, Sr 2 Al 2 Si 10 ON 16 :Eu, Sr 3 Al 3 Si 15 O 3 N 23 :Eu, SrAlSi 5 O 2 N 7 :Eu, Sr 6 Al 6 Si 36 O 3 N 56 :Eu, SrAlSi 6 ON 9 :Eu, Sr 3 Al 3 Si 18 O 6 N 25 :Eu.

26. The phosphor according to claim 20 , wherein in an X-ray powder diffraction pattern by CoKα ray, when maximum peaks are defined as a, b, and c, respectively, with Bragg angle (2θ) in a range from 28.5° to 29.5°, 35.5° to 36.5°, and 41.0° to 42.0°, and a peak intensity ratio of a to b is defined as I(alb), and a peak intensity ratio of c to b is defined as I(c/b), a relation of a, b, c is given satisfying 0.20<I(a/b), I(c/b)<0.80.

27. The phosphor according to claim 20 , wherein when a value of relative intensity of a maximum peak in the emission spectrum is defined as P 25 when the phosphor is irradiated with a specified monochromatic light in the wavelength range from 350 nm to 550 nm as the excitation light at 25° C., and a value of relative intensity of a maximum peak is defined as P 200 when the phosphor is irradiated with the specified monochromatic light as the excitation light at 200° C., a relation of P 25 and P 200 is given satisfying (P 25 −P 200 ) / P 25 ×100≦35.

28. The phosphor according to claim 20 , containing Sr of 20.0 to 27.0 wt %, Al of 5.0 to 9.0 wt %, Si of 30.0 to 39.0 wt %, O of 0.5 to 6.0 wt %, N of 26.0 to 32.0 wt %, and Eu of beyond 0 to 3.5 wt %, wherein x of chromaticity of the emission spectrum (x, y) is in the range from 0.4500 to 0.6000, and y of the chromaticity of the emission spectrum (x, y) is in the range from 0.3500 to 0.5000.

29. The phosphor according to claim 28 , wherein when the phosphor is irradiated with the monochromatic light having the wavelength range from 350 nm to 550 nm as the excitation light, a relation of P H and P L is given satisfying (P H −P L )/P H ≦0.20, when a peak intensity of a maximum peak in a spectrum of light emission that occurs by absorbing the excitation light that makes the peak intensity highest is defined as P H , and a peak intensity of a maximum peak in a spectrum of light emission that occurs by absorbing the excitation light that makes the peak intensity smallest is defined as P L .

30. The phosphor according to claim 20 , wherein the phosphor is a powdery form.

31. A method of manufacturing the phosphor according to claim 20 wherein by using a crucible composed of nitride as a firing crucible, raw materials are fired at temperature of 1400° C. or more and 2000° C. or less in an atmosphere containing one or more kind of gas selected from nitrogen gas, rare gas, and ammonia gas.

Assignments (6)
CHANGE OF NAME Recorded Sep 5, 2017
From: MITSUBISHI RAYON CO., LTD.
To: MITSUBISHI CHEMICAL CORPORATION
Reel/Frame 043750/0834 →
MERGER Recorded Sep 4, 2017
From: MITSUBISHI CHEMICAL CORPORATION
To: MITSUBISHI RAYON CO., LTD.
Reel/Frame 043750/0207 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 28, 2011
From: DOWA ELECTRONICS MATERIALS CO., LTD.
To: MITSUBISHI CHEMICAL CORPORATION
Reel/Frame 026511/0406 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 7, 2008
From: DOWA HOLDINGS CO., LTD.
To: DOWA ELECTRONICS MATERIALS CO., LTD.
Reel/Frame 020323/0715 →
CHANGE OF NAME Recorded Nov 5, 2007
From: DOWA MINING CO., LTD.
To: DOWA HOLDINGS CO., LTD.
Reel/Frame 020121/0161 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 20, 2006
From: SAKANE, KENJI; NAGATOMI, AKIRA
To: DOWA MINING CO., LTD.
Reel/Frame 017513/0278 →