Phosphor for light sources and associated light source

Abstract

A phosphor for light sources, the emission from which lies in the short-wave optical spectral region, as a garnet structure A 3 B 5 O 12 . It is activated with Ce, the second component B representing at least one of the elements Al and Ga, and the first component A is terbium or terbium together with at least one of the elements Y, Gd, La and/or Lu. In a preferred embodiment, a phosphor having a garnet of structure (Tb 1-x-y RE x Ce y ) 3 (Al,Ga) 5 O 12 , where RE=Y, Gd, La and/or Lu; 0≦ x ≦0.5− y; 0<y< 0.1 is used.

1 - 11 . (canceled)  
     
     
         12 . A process for producing an Al-containing Tb-garnet phosphor, a Ga-containing Tb-garnet phosphor, or a Ga,Al-containing Tb-garnet phosphor, the process comprising: 
 (a) intimately mixing an oxide of cerium, an oxide of terbium or terbium and at least one of Y, Gd, La, and/or Lu, at least one oxide of Al and Ga, and at least one flux to form a mixture; and    (b) firing the mixture in forming gas to form the phosphor.    
     
     
         13 . The process of  claim 12  wherein the flux is BaF 2 , HBO 3 , or both.  
     
     
         14 . The process of  claim 12  wherein the forming gas is a mixture of nitrogen and hydrogen gases wherein the hydrogen is 2.3% by volume.  
     
     
         15 . The process of  claim 12  wherein a stoichiometric excess of aluminum oxide is used to form the mixture.  
     
     
         16 . The process of  claim 12  wherein the mixture is fired at a temperature from 1450° C. to 1550° C.  
     
     
         17 . The process of  claim 12  wherein the mixture is milled after firing and then fired for a second time in forming gas.  
     
     
         18 . The process of  claim 17  wherein the firings are performed at a temperature from 1450° C. to 1550° C.  
     
     
         19 . The process of  claim 18  wherein the firings are each for three hours.