Method of fabricating translucent phosphor ceramics
One embodiment provides a method for fabricating a translucent phosphor ceramic compact comprising: heating a precursor powder to at least about 1000° C. under a reducing atmosphere to provide a pre-conditioned powder, forming an intermediate compact comprising the pre-conditioned powder and a flux material, and heating the intermediate compact under a vacuum to a temperature of at least about 1400° C. In another embodiment, the compact may be a cerium doped translucent phosphor ceramic compact comprising yttrium, aluminum, oxygen, and cerium sources. Another embodiment may be a light emitting device having the phosphor translucent ceramic provided as described herein.
1. A method for fabricating a cerium doped translucent phosphor ceramic compact comprising:
heating a precursor powder comprising yttrium, aluminum, oxygen, and cerium sources to a temperature of from about 1000° C. to about 1350° C. under a reducing atmosphere to provide a pre-conditioned powder;
forming an intermediate compact comprising the pre-conditioned powder and a flux material; and
heating the intermediate compact under a vacuum at a temperature of from about 1400° C. to about 1800° C.
2. The method of claim 1 , further comprising heating the precursor powder under air at about 1000° C. to about 1350° C. prior to heating under a reducing atmosphere.
3. The method of claim 1 wherein the intermediate compact further comprises a binder.
4. The method of claim 3 , wherein the binder is a polymer binder.
5. The method of claim 1 wherein the heating the intermediate compact under a vacuum is at a temperature from about 1500° C. to about 1700° C.
6. The method of claim 1 wherein the precursor powder has a cerium to yttrium molar ratio of about 0.0002 to about 0.02.
7. The method of claim 1 wherein the precursor powder has a cerium to yttrium molar ratio of about 0.00025 to about 0.0065.
8. A method for fabricating a translucent phosphor ceramic compact comprising:
heating a precursor powder to at least about 1000° C. under a reducing atmosphere to provide a pre-conditioned powder;
forming an intermediate compact comprising the pre-conditioned powder and a flux material; and
heating the intermediate compact under a vacuum to a temperature of at least about 1400° C.
9. The method of claim 8 , wherein the precursor powder is heated to a temperature of about 1000° C. to about 1400° C.
10. The method of claim 8 , wherein the precursor powder is heated to a temperature of about 1100° C. to about 1300° C.
11. The method of claim 8 , wherein the intermediate compact is heated to a temperature of about 1400° C. to about 1900° C.
12. The method of claim 8 , wherein the intermediate compact is heated to a temperature of about 1500° C. to about 1700° C.
13. The method of claim 8 , wherein the reducing atmosphere comprises a mixture of at least one inert gas and hydrogen.
14. The method of claim 13 , wherein the inert gas is argon or nitrogen.
15. The method of claim 13 , wherein the reducing atmosphere comprises about 1% to about 10% by volume of hydrogen gas in nitrogen gas.
16. The method of claim 8 , wherein the precursor powder comprises one or more of: amorphous yttrium oxide, yttrium aluminum perovskite, and yttrium aluminum monoclinic.
17. The method of claim 8 , wherein the pre-conditioned powder comprises yttrium aluminum garnet.
18. The method of claim 8 , wherein the intermediate compact further comprises a binder.
19. The method of claim 18 , wherein the binder is a polymer binder.
20. The method of claim 8 , wherein said translucent phosphor ceramic compact comprises a rare earth doped phosphor material having garnet structure.
21. The method of claim 8 , wherein said translucent phosphor ceramic compact comprises a composition of (A 1-x E x ) 3 B 5 O 12 , wherein
A is Y, Gd, La, Lu, Tb, or a combination thereof;
x is from about 0.00005 to about 0.1;
B is Al, Ga, In, or a combination thereof; and
E is Ce, Eu, Tb, Nd, or a combination thereof.