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

• US 7,476,336 B2
• Filed: 06/10/2005
• Issued: 01/13/2009
• Est. Priority Date: 04/28/2005
• Status: Expired due to Fees

• Current Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Original Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Inventors: Nagatomi, Akira, Yamashita, Shuji, Ikuta, Tetsuya
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US11/149,317
• Publication Number:
  US 20060244356A1
• Time in Patent Office: 1,313 Days
• Field of Search: 252/301.4 F, 252/301.6 F, 252/301.4 R, 252/301.6 R, 313/503, 257/98
• US Class Current: 252/301.40F
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7715 containing cerium
• CPC Class Codes: C09K 11/77218 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: C09K 11/7728 containing europium
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• 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 range from green color to red color, and having excellent emission efficiency and luminance. A phosphor is provided, which is given by a general composition formula expressed by MmAaBbOoNn:Z, (where element M is more than one kind of element having bivalent valency, element A is more than one kind of element having tervalent valency, 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 acting as an activator.), satisfying 2.5<(a+b)/m<4.5, 0<a/m<2.0, 2.0<b/m<4.0, 0<o/m<1.0, o<n, n=2/3m+a+4/3b−2/3o.

Claims

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

Z,

where element M is at least one alkaline earth metal,

element A is Al, or Al and at least one Ga and In,

element B is Si or, Si and Ge,

element Z is a rare earth or transitional metal,

O is oxygen,

N is nitrogen, and

0<

a<

2, 2<

b<

4, 0<

o<

1, n=2/3(1−

o)+a+4/3b2/3o,

wherein the phosphor is irradiated at 25°

C. with a predetermined monochromatic light in a wavelength range from 300 nm to 550 nm as an excitation light, the value of the relative intensity of a maximum peak in an emission spectrum is defined as P₂₅, and when the phosphor is irradiated at 100°

C. with the predetermined monochromatic light as the excitation light, the value of the relative intensity of the maximum peak is defined as P₁₀₀, the relation of P₂₅ and P₁₀₀ is given satisfying (P₂₅−

P₁₀₀)/P₂₅×

100≦

10.0.

5. A method of manufacturing the phosphor according to claim 1, wherein as raw materials, a compound of one kind or more elements selected from oxide, nitride, carbonate, hydroxide, and basic carbonate of the element M, a compound of one kind or more elements selected from oxide, nitride, carbonate, hydroxide, and basic carbonate of the element A, a compound of one kind or more elements selected from oxide, nitride, carbonate, hydroxide, and basic carbonate of the element B, and a compound of one kind or more elements selected from oxide, nitride, carbonate, hydroxide, and basic carbonate of the element Z are mixed to obtain the phosphor expressed by the general composition formula MAaBbOoNn:

Z (where 0<

a<

2, 2<

b<

4, 0<

o1, n=2/3(a−

o)+a+4/3gb2/3o), and by using a crucible composed of nitride as a firing crucible, the raw materials are fired at temperature of not less than 1600°

C. and not more than 2000°

C., in a state that 0.1 ml/min or more of gas containing 90% or more of nitrogen gas, and the balance being one or more gases selected from the group consisting of inert and reducing gases, is flown in a furnace.

6. The manufacturing method of the phosphor according to claim 5, wherein the raw material is fired by setting pressure inside furnace at 0.5 MPa or less.

7. The manufacturing method of the phosphor according to claim 5, wherein the crucible composed of nitride is a BN crucible.

8. The manufacturing method of the phosphor according to claim 5, wherein the raw material is fired in a powdery state.

9. The manufacturing method of the phosphor according to claim 5, wherein carbonate of the element M is used as the raw material of the element M.

10. A light emitting device, having the phosphor according to claim 1 and a light emission part for emitting light of a first wavelength, wherein the light with a 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.

11. The light emitting device according to claim 10, wherein the first wavelength is the wavelength in a range from 300 nm to 550 nm.

12. The light emitting device according to claim 10, wherein the light emission part for emitting the light of the first wavelength is an LED.

2. A phosphor, which is given by a general composition formula expressed by MAaBbOoNn:

Z,

where element M is at least one alkaline earth metal,

element A is Al, or Al and at least one Ga and In,

element B is Si or, Si and Ge,

element Z is a rare earth or transitional metal,

O is oxygen,

N is nitrogen, and

0<

a<

2, 2<

b<

4, 0<

o<

1, n=2/3(1−

o)+a+4/3b2/3o, containing;

not less than 33.0 wt % and not more than 40.0 wt % of Sr;

not less than 1.0 wt % and not more than 6.0 wt % of Al;

not less than 25.0 wt % and not more than 31.0 wt % of Si;

not less than 0.5 wt % and not more than 6.0 wt % of O;

not less than 20.0 wt % and not more than 26.0 wt % of N;

and

not less than 0.1 wt % and not more than 8.0 wt % of Eu, wherein when the phosphor is irradiated with more than one kind of monochromatic light or continuous light in the wavelength range from 300 nm to 550 nm as the excitation light, the phosphor has the emission spectrum with a maximum peak wavelength in a range from 630 to 660 nm.

13. A light emitting device, having the phosphor according to claim 2 and a light emission part for emitting light of a first wavelength, wherein the light with a 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.

3. A phosphor, which is given by a general composition formula expressed by MAaBbOoNn:

Z,

where element M is at least one alkaline earth metal,

element A is Al, or Al and at least one Ga and In,

element B is Si or, Si and Ge,

element Z is a rare earth or transitional metal,

O is oxygen,

N is nitrogen, and

0<

a<

2, 2<

b<

4, 0<

o<

1, n=2/3(1−

o)+a4/3b2/3o,

which has an orthorhombic crystal structure.

14. A light emitting device, having the phosphor according to claim 3 and a light emission part for emitting light of a first wavelength, wherein the light with a 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.

4. A phosphor, which is given by a general composition formula expressed by MAaBbOoNn:

Z,

where element M is at least one alkaline earth metal,

element A is Al, or Al and at least one Ga and In,

element B is Si or, Si and Ge,

element Z is a rare earth or transitional metal,

O is oxygen,

N is nitrogen, and

0<

a<

2, 2<

b<

4, 0<

o<

1, n=2/3(1−

o)+a+4/3b2/3o,

which has an x-ray powder diffraction pattern by CoKα

ray with two peaks from 42.0°

to 43.1°

of Bragg angle (2θ

) among the diffraction peaks with 30% or more relative intensity with respect to the relative intensity of the maximum peak,

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 a powdery phosphor containing the primary particle and the aggregates is not less than 1.0 μ

m and not more than 20.9 μ

m,

wherein the aggregates of the primary particle contains a columnar particle.

15. A light emitting device, having the phosphor according to claim 4 and a light emission part for emitting light of a first wavelength, wherein the light with a 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.