Phosphor, method of manufacturing the same, and light-emitting device

1. A phosphor comprising

a luminescent material expressed by the general formula (A 1−x R x M 2 X) m (M 2 X 4 ) n (wherein the element A is one or more types of element selected from Li, Na, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Gd, and Lu, the element R is one or more types of activating agent selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb, the element M is one or more types of element selected from Si, Ge, Sn, Ti, Hf, Zr, Be, B, Al, Ga, In, Tl, and Zn, the element X is one or more types of element selected from oxygen and nitrogen, n and m are integers of 1 or more, and x is a real number defined by 0<x<1), wherein

the value of n/m is (8/5)<n/m<(5/3).

2. The phosphor according to claim 1 , wherein the element A is one or more types selected from Ca, Sr, Ba and La.

3. The phosphor according to claim 1 , wherein the element R is Eu.

4. The phosphor according to claim 1 , wherein the element M is one or more types selected from Si and Al.

5. The phosphor according to claim 1 , wherein the luminescent material is expressed by the general formula (A 1−x R x ) m Si 6n−5m−s Al 7m−4n+s O s N m+4n−s (wherein s is a real number defined by 0≦s≦m).

6. The phosphor according to claim 1 , wherein the concentration of the luminescent material is 80% by volume or more, and the remainder is one or more types selected from β-sialon, unreacted silicon nitride or aluminum nitride, oxynitride glass, SrSiAl 2 N 2 O 3 , Sr 2 Al 2 Si 10 N 14 O 4 , SrSi (10−n) Al (18+n) O n N (32−n) (n˜1), and SrSi 6 N 8 .

7. A light-emitting device that is provided with an emission light source and a phosphor to be excited by the emission light source to emit fluorescent light, wherein the phosphor described in claim 1 is used for the phosphor.

8. The light-emitting device according to claim 7 , wherein the phosphor further contains one or more types of phosphor selected from β-SiAlON: Eu, YAG:Ce, (Ca, Sr, Ba) 2 SiO 4 :Eu, α-SiAlON:Eu, (Ca, Sr, Ba) 2 Si 5 N 8 :Eu, and (Ca, Sr) AlSiN 3 :Eu.

9. The light-emitting device according to claim 7 , wherein the emission light source is at least one selected from the group consisting of an LED chip, an inorganic EL chip and an organic EL chip, that emit lights having a wavelength of 330 to 500 nm.

10. The light-emitting device according to claim 7 , wherein the emission light source is an LED chip that emits light having a wavelength of 330 to 500 nm, and the phosphor is dispersed in a sealing resin that is formed so as to enclose the LED chip.

11. The light-emitting device according to claim 10 , wherein the phosphor is dispersed in the sealing resin such that it is densely dispersed in a vicinity of the LED chip.

12. The light-emitting device according to claim 7 , wherein the emission light source is an LED chip that emits light having a wavelength of 330 to 500 nm, and the phosphor is directly adhered to the LED chip.

13. The light-emitting device according to claim 12 , wherein the phosphor is directly adhered such that it covers at least one surface of the LED chip.

14. The light-emitting device according to claim 13 , wherein the phosphor has a layer structure.

15. The light-emitting device according to claim 7 , wherein the light-emitting device contains a plurality of LED chips.

16. The phosphor according to claim 1 , wherein the value of x is 0<x≦0.2.

17. A method of manufacturing a phosphor comprising: a mixing step in which a starting raw material is mixed so as to prepare a mixed raw material; a firing step in which this mixed raw material is fired; and a heat treatment step in which the mixed raw material obtained in the previous step is heat treated, wherein

the phosphor comprises a luminescent material expressed by the general formula (A 1−x R x M 2 X) m (M 2 X 4 ) n (wherein the element A is one or more types of element selected from Li, Na, Be, Mg, Ca, Sr, Ba, Sc, Y, La, Gd, and Lu, the element R is one or more types of activating agent selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb, the element M is one or more types of element selected from Si, Ge, Sn, Ti, Hf, Zr, Be, B, Al, Ga, In, Tl, and Zn, the element X is one or more types of element selected from oxygen and nitrogen, n and m are integers of 1 or more, and x is a real number defined by 0<x<1), wherein

the value of n/m is (8/5)<n/m<(5/3).

18. The method of manufacturing a phosphor according to claim 17 , wherein there are further provided:

a first pulverizing and classifying step in which the mixed raw material obtained from the firing step is pulverized and classified; and

a second pulverizing and classifying step in which the mixed raw material obtained from the heat treatment step is pulverized and classified, and

the aforementioned previous step is the first pulverizing and classifying step.

19. The method of manufacturing a phosphor according to claim 17 , wherein the starting raw material contains LiSi 2 N 3 .

20. The method of manufacturing a phosphor according to claim 17 , wherein a powder of a target phosphor is synthesized in advance, and this is added as a seed to the mixed raw material.

21. The method of manufacturing a phosphor according to claim 17 , wherein the value of x is 0<x≦0.2.

22. The method of manufacturing a phosphor according to claim 17 , wherein when the element A is La, the starting raw material contains LaSi 3 N 5 .

23. The method of manufacturing a phosphor according to claim 17 , wherein when the element A is one or more types of element selected from elements that have a bivalent valency, the starting raw material contains one or more types of raw material selected from ASi 2 , ASiN 2 , A 2 Si 5 N 8 , A 3 Al 2 N 4 , and ASi 6 N 8 .