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

• US 20060197439A1
• Filed: 03/02/2006
• Published: 09/07/2006
• Est. Priority Date: 03/04/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Dowa Mining Company Limited
• Inventors: Nagatomi, Akira, Sakane, Kenji
• Granted Patent: US 7,524,437 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77218 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• 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: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

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

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 the element 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.

2. The phosphor according to claim 1, satisfying 0.5≦

a/m≦

1.5, 3.5<

b/m<

6.5, 0<

o/m<

4.0.

3. The phosphor according to claim 1, satisfying 0.8≦

a/m≦

1.2, 4.0≦

b/m≦

6.0, 0<

o/m≦

3.0.

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

5. The phosphor according to claim 1, wherein the element M is more than one kind of element selected from the group consisting of Mg, Ca, Sr, Ba, Zn, the element A is more than one kind of element selected from the group consisting of Al, Ga, In, the element B is Si and/or Ge, and the element Z is more than one kind of element selected from the group consisting of Eu, Ce, Pr, Th, and Mn.

6. The phosphor according to claim 1, wherein the element M is Sr, the element A is Al, the element B is Si, and the element Z is Eu and/or Ce.

7. The phosphor according to claim 1, wherein when the general formula is expressed by MmAaBbOoNn:

Zz, the 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.

8. The phosphor according to claim 1, which is given as formulas expressed by:

Sr₆Al₆Si₁₈O₃N₃₂;

Ce, SrAlSi₃ON₅;

Ce, Sr₃Al₃Si₉O₆N₁₃;

Ce, Sr₆Al₆Si₂₄O₃N₄₀;

Ce, Sr₃Al₃Si₁₂O₃N₁₉;

Ce, Sr₃Al₃Si₁₂O₆N₁₇;

Ce, Sr₆Al₆Si₂₇O₃N₄₄;

Ce, Sr₂Al₂Si₉O₂N₁₄;

Ce, Sr₆Al₆Si₂₇O₁₂N₃₈;

Ce, Sr₂Al₂Si₁₀ON₁₆;

Ce, Sr₃Al₃Si₁₅O₃N₂₃;

Ce, SrAlSi₅O₂N₇;

Ce, Sr₆Al₆Si₃₆O₃N₅₆;

Ce, SrAlSi₆ON₉;

Ce, Sr₃Al₃Si₁₈O₆N₂₅;

Ce, Sr₆Al₆Si₁₈O₃N₃₂;

Eu, SrAlSi₃ON₅;

Eu, Sr₃Al₃Si₉O₆N₁₃;

Eu, Sr₆Al₆Si₂₄O₃N₄₀;

Eu, Sr₃Al₃Si₁₂O₃N₁₉;

Eu, Sr₃Al₃Si₁₂O₆N₁₇;

Eu, Sr₆Al₆Si₂₇O₃N₄₄;

Eu, Sr₂Al₂Si₉O₂N₁₄Eu, Sr₆Al₆Si₂₇O₁₂N₃₈;

Eu, Sr₂Al₂Si₁₀ON₁₆;

Eu, Sr₃Al₃Si₁₅O₃N₂₃;

Eu, SrAlSi₅O₂N₇;

Eu, Sr₆Al₆Si₃₆O₃N₅₆;

Eu, SrAlSi₆ON₉;

Eu, Sr₃Al₃Si₁₈O₆N₂₅;

Eu.

9. 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 0 to 3.5 wt %, wherein when the phosphor is irradiated with more than one kind of monochromatic light or continuous light having the wavelength range from 350 nm to 500 nm as an excitation light, a peak wavelength in the emission spectrum is in the range from 500 to 600 nm, and 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.

10. 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 Eu of 0 to 3.5 wt %, wherein when the phosphor is irradiated with more than one kind of monochromatic light or continuous light having the wavelength range from 350 nm to 500 nm as an excitation light, the peak wavelength of the emission spectrum is in the range from 550 to 650 nm, and x of the 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.

11. The phosphor according to claim 10, wherein when the phosphor is irradiated with the monochromatic light having the wavelength range from 350 nm to 550 nm as an excitation light, the 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 it highest is defined as P_H, and the peak intensity of the maximum peak in the spectrum of light emission that occurs by absorbing the excitation light that makes it smallest is defined as P_L.

12. The phosphor according to claim 1, wherein in an X-ray powder diffraction pattern by CoKα

ray, when the maximum peak is 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 the peak intensity ratio of c to b is defined as I(c/b), the relation of a, b, c is given satisfying 0.20<

I(a/b), I(c/b)<

0.80.

13. The phosphor according to claim 1, wherein when the value of relative intensity of the maximum peak in the emission spectrum is defined as P₂₅ 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 the value of the relative intensity of the maximum peak is defined as P₂₀₀ when the phosphor is irradiated with the specified monochromatic light as the excitation light at 200°

C., the relation of P₂₅ and P₂₀₀ is given satisfying (P₂₅−

P₂₀₀)/P₂₅×

100≦

35.

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

15. The phosphor according to claim 14, containing a primary particle with particle size of 20 μ

m 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 μ

m or more and 20.0 μ

m or less.

16. 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 more than one kind of gas selected from nitrogen gas, rare gas, and ammonia gas.

17. The method of manufacturing the phosphor according to claim 16, wherein the raw materials are fired by setting pressure inside furnace at 0.5 MPa or less.

18. The method of manufacturing the phosphor according to claim 16, wherein the crucible composed of nitride is a BN crucible.

19. The method of manufacturing the phosphor according to claim 16, wherein the raw materials are fired, with 0.1 ml/min or more gas containing more than one kind of gas selected from the nitrogen gas, rare gas, and the ammonia gas flowing inside the furnace.

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

21. An emission device, having a phosphor according to claim 15 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.

22. The emission device according to claim 21, wherein the first wavelength is in a range from 350 nm to 550 nm.

23. The emission device according to claim 21, wherein the emission part emitting the first wavelength is an LED.