Phosphor, process for producing the same, and luminescent device

1. A phosphor comprising:

an inorganic crystal having a crystal structure of an AlN crystal or an AlN solid solution crystal, the inorganic crystal comprising: a wurtzite-type AlN crystal structure, a crystal structure selected from 2H δ ; 27R; 21R; 12H; 15R; and 8H, a crystal structure having an Al(O, N) 4 tetrahedron skeleton therein, or a combination thereof; and

at least europium incorporated therein as a solid solution,

wherein a composition of the phosphor is given by Eu a A b Al c Si d O e N f (here, A is one or two or more kinds of elements selected from Mg, Ca, Sr, Ba, Zn, and Cd, and a+b+c+d+e+f=1) and following conditions are satisfied:

0.00001≦a≦0.1  (i);

0.0001≦b≦0.2  (ii);

0.4≦c≦0.55  (iii);

0.005≦d≦0.2  (iv);

0.001≦e≦0.05  (v); and

0.3≦f≦0.55  (vi), and

wherein the phosphor emits fluorescence being derived from a divalent europium ion and having a peak at a wavelength in a range of 430 nm to 500 nm upon exposure to an excitation source.

2. The phosphor according to claim 1 , further comprising:

oxygen incorporated therein as a solid solution.

3. The phosphor according to claim 1 , further comprising: the element A and silicon incorporated therein as a solid solution.

4. The phosphor according to claim 3 wherein the element A is Zn.

5. The phosphor according to claim 3 wherein the element A is Ba.

6. The phosphor according to claim 1 , wherein the excitation source is any one of an ultraviolet or visible light having a wavelength of 100 nm to 420 nm, an electron beam, and an X-ray.

7. A manufacturing method of a phosphor comprising:

holding a raw material mixture comprising at least: Eu metal, oxide, carbonate, nitride, fluoride, chloride, oxynitride, or a combination thereof; A metal, oxide, carbonate, nitride, fluoride, chloride, oxynitride, or a combination thereof (here, A is one or two or more kinds of elements selected from Mg, Ca, Sr, Ba, Zn, and Cd); silicon nitride; and aluminum nitride, in a bulk density of 40% or less; and

firing the thus-held mixture in a nitrogen atmosphere of 0.1 MPa or higher to 100 MPa or lower in a temperature range of 1500° C. or higher and 2200° C. or lower such that the phosphor of claim 1 is produced.

8. The manufacturing method of the phosphor according to claim 7 wherein a content (atomic %) of silicon atom contained in the raw material mixture is lower than a content (atomic %) of aluminum atom.

9. A lighting device comprising: an emission source emitting light of wavelength of 330 to 420 nm; and a phosphor, wherein the phosphor comprises a phosphor recited in claim 1 .

10. The lighting device according to claim 9 , wherein the emission source comprises a LED or a LD, wherein the phosphor further comprises: a green phosphor having an emission peak at a wavelength of 520 nm to 550 nm by an excitation light of 330 to 420 nm; and a red phosphor having an emission peak at a wavelength of 600 nm to 700 nm by the excitation light of 330 to 420 nm.

11. The lighting device according to claim 9 , wherein the emission source comprises: a LED or a LD, and wherein the phosphor further comprises a yellow phosphor having an emission peak at a wavelength of 550 nm to 600 nm by an excitation light of 330 to 420 nm.

12. An image display device comprising: an excitation source and a phosphor, wherein the phosphor comprises: a phosphor recited in claim 1 .

13. The image display device according to claim 12 , comprising: any one of a fluorescent display tube (VFD), a field emission display (FED or SED), and a cathode-ray tube (CRT), wherein the excitation source is an electron beam whose acceleration voltage is in range of 10 V or higher to 30 kV or lower.