Kimzeyite garnet phosphors
View Patent ↗A phosphor of formula I is included in a phosphor composition in a lighting apparatus capable of emitting white light, Ca 3-x-z Sr x Ce z M 1 2 M 2 AlSiO 12 (I) wherein M 1 is Hf, Zr, or a combination thereof; M 2 is Al, or a combination of Al and Ga; z<3−x; and 0.2>x≧0. The lighting apparatus includes a semiconductor light source in addition to the phosphor composition.
1. A lighting apparatus capable of emitting white light, said lighting apparatus comprising
a semiconductor light source; and
a phosphor composition radiationally coupled to the light source, and comprising a phosphor that emits blue light upon excitation by the semiconductor light source, of formula I
Ca 3-x-z Sr x Ce z M 1 2 M 2 AlSiO 12 (I)
wherein
M 1 is Hf, Zr, or a combination thereof;
M 2 is Al, or a combination of Al and Ga;
x<3−z;
0.2>z>0.
2. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 3-z Ce z M 1 2 Al 2 SiO 12 .
3. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 3-x-z Sr x Ce z Hf 2 M 2 Al SiO 12 .
4. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 3-x-z Sr x Ce z Hf 2 Al 2 SiO 12 .
5. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 3-x-z Sr x Ce z Zr 2 Al 2 SiO 12 .
6. A lighting apparatus according to claim 1 , wherein 0.15>z≧0.03.
7. A lighting apparatus according to claim 1 , wherein 0.05>z>0.01.
8. A lighting apparatus according to claim 1 , wherein x≦1.5.
9. A lighting apparatus according to claim 1 , wherein 0.5<x≦1.5.
10. A lighting apparatus according to claim 1 , wherein the light source is a semiconductor light emitting diode emitting radiation of wavelength ranging from about 350 to about 450 nm.
11. A lighting apparatus according to claim 8 , wherein the semiconductor light emitting diode comprises a nitride compound semiconductor represented by the formula In i Ga j Al k N;
wherein
0≦i;
0≦j,
0≦k, and
i+j+k=1.
12. A lighting apparatus according to claim 1 , wherein said phosphor composition further comprises one or more phosphors in addition to the phosphor of formula I.
13. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 2.97 Ce .03 Hf 2 Al 2 SiO 12 .
14. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 2.97 Ce 0.03 Zr 2 Al 2 SiO 12 .
15. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 2.37 Sr 0.6 Ce 0.03 Hf 2 Al 2 SiO 12 .
16. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 1.47 Sr 1.5 Ce 0.03 Hf 2 Al 2 SiO 12 .
17. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 1.97 SrCe 0.03 Hf 2 Al 2 SiO 12 .
18. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 2.97 Ce .03 Hf 2 GaAlSiO 12 .
19. A lighting apparatus according to claim 1 , wherein said phosphor is of formula Ca 1.97 SrCe 0.03 Hf 2 GaAlSiO 12 .