Phosphor, manufacturing method therefor, and light-emitting device using the phosphor
The present invention provides a red-light emitting phosphor that exhibits high luminous efficacy and emits light when excited by light having an emission peak in the blue region; and a method for manufacturing said phosphor. The phosphor represented by general formula (A): a (Si 1-x-y ,Ti x ,Mn y )F b and also characterized in that the half-band width of a diffraction pattern attributed to the (400) plane is not less than 0.2° determined by X-ray powder diffractometry. This phosphor can be manufactured by preparing a reaction solution consisting of an aqueous solution containing potassium permanganate and hydrogen fluoride, immersing a silicon source in said reaction solution, and reacting them for 20 to 80 minutes.
1. A phosphor represented by the formula (A):
K a (Si 1-x-y ,Ti x ,Mn y )F b (A)
in which a, b, x and y are numbers satisfying the conditions of
1.8≤a≤2.2,
5.2≤b≤6.3,
0≤x≤0.3, and
0.01<y≤0.05;
wherein a half-band width of a diffraction pattern attributed to the (400) plane is not more than 0.2° determined by X-ray powder diffractometry and the external quantum efficiency of said phosphor is not less than 15%.
2. The phosphor according to claim 1 , wherein the half-band width of a diffraction pattern attributed to the (222) plane is not more than 0.2° determined by X-ray powder diffractometry.
3. The phosphor according to claim 1 , which is in the form of particles having a mean particle size of 1 to 50 μm.
4. The phosphor according to claim 1 , wherein the oxygen and fluorine contents satisfy the condition of:
[oxygen content]/[(fluorine content)±(oxygen content)]<0.05.
5. The phosphor according to claim 1 , wherein said external quantum efficiency of said phosphor is not less than 20%.
6. A method for manufacturing the phosphor according to claim 1 , comprising:
preparing an aqueous solution as a reaction solution comprising potassium permanganate and hydrogen fluoride,
immersing a silicon source in said reaction solution,
reacting them for 20 to 80 minutes, and
peeling off a formed phosphor crystal spontaneously from the silicon source.
7. The method according to claim 6 , wherein said silicon source is selected from the group consisting of single crystal silicon, polycrystal silicon, and amorphous silicon.
8. The method according to claim 6 , wherein said silicon source is a silicon substrate.
9. The method according to claim 6 , wherein said reaction solution comprises potassium permanganate and hydrogen fluoride in a molar ratio of 1:200 to 1:40.
10. The method according to claim 6 , wherein said reaction solution contains potassium permanganate in an amount of 1 wt % or more.
11. A light-emitting device comprising
a light-emitting element radiating light in the wavelength range of 440 to 470 nm inclusive, and
a phosphor layer comprising the phosphor according to claim 1 .
12. The light-emitting device according to claim 11 , wherein said phosphor layer further comprises a green- or yellow-light emitting phosphor.
13. The light-emitting device according to claim 12 , wherein said green- or yellow-light emitting phosphor is selected from the group consisting of (Sr,Ca,Ba) 2 SiO 4 :Eu, Ca 3 (Sc,Mg) 2 Si 3 O 12 :Ce, (Y,Gd) 3 (Al,Ga) 5 O 12 :Ce, (Ca,Sr,Ba)Ga 2 S 4 :Eu, (Ca,Sr,Ba)Si 2 O 2 N 2 :Eu and (Ca,Sr)-αSiAlON.
14. The light-emitting device according to claim 11 , wherein said phosphor layer furthermore contains an orange- or red-light emitting phosphor.
15. The light-emitting device according claim 14 , wherein said orange- or red-light emitting phosphor is selected from the group consisting of (Sr,Ca,Ba) 2 SiO 4 :Eu, Li(Eu,Sm)W 2 O 8 , (La,Gd,Y) 2 O 2 S:Eu, (Ca,Sr,Ba)S:Eu, (Sr,Ba,Ca) 2 Si 5 N 8 :Eu, and (Sr,Ca)AlSiN 3 :Eu.
16. The phosphor according to claim 1 , which is made by a method comprising:
preparing an aqueous solution as a reaction solution comprising potassium permanganate and hydrogen fluoride,
immersing a silicon source in said reaction solution,
reacting them for 20 to 80 minutes, and
peeling off a formed phosphor crystal spontaneously from the silicone source.