Method of applying phosphor coatings

1. A method of applying a phosphor coating, comprising:

(a) forming a suspension of a phosphor and a polymer binder system comprising a polymer binder dissolved in a solvent, the polymer binder being capable of decomposing thermally, the phosphor comprising at least one of:

(S 1-x-y-z Ba x Ca y )Si 2 N 2 O 2 :Eu z , where 0<x<0.2, 0<y<0.2 and 0<z<0.1;

Ca 1-x-y Sr x Si 2 N 2 O 2 :Eu y , where 0<x<0.5 and 0<y<0.1;

(Sr 1-x-y-z Ca x Ba y ) 2 Si 5 N 8 :Eu z , where 0<x<1, 0<y<1 and 0<z<0.1;

(Sr 1-x-y-z Ba x Ca y ) 2 Si 5-a Al a N 8-a O a :Eu z , where 0<x<1, 0<y<1, 0<z<0.1 and 0<a<4;

and (Sr 1-x-y-z Ba x Ca y )Si 2 N 2 O 2 :Yb z , where 0<x<0.2, 0<y<0.2 and 0<z<0.1;

(b) applying the suspension to a substrate to form a coating;

(c) drying the coating; and

(d) baking the coating in a nitrogen atmosphere at less than about 400° C. to thermally decompose the polymer binder to form the phosphor coating.

2. The method of claim 1 wherein the polymer binder system comprises up to 20 wt. % of the polymer binder, 0-5 wt. % of a surfactant, and 0-5 wt. % of a plasticizer.

3. The method of claim 2 wherein the solvent is at least one of xylene, toluene, and isopropyl alcohol.

4. The method of claim 3 wherein the polymer binder is polyisobutyl methacrylate.

5. The method of claim 2 wherein the plasticizer is dibutyl phthalate.

6. The method of claim 1 wherein the coating is baked at less than about 350° C.

7. The method of claim 1 wherein the coating is baked at a temperature between about 300° C. and 350° C.

8. The method of claim 1 wherein the polymer binder is polyethyl methacrylate.

9. The method of claim 1 wherein the polymer binder is polyisobutyl methacrylate.