This proposal seeks to improve the power efficiency of field emission displays by increasing the luminous efficiency of the phosphors in the display. The proposed work will utilize ultra-sound treatment (UST) of materials to accomplish defect engineering of the phosphor materials. UST is a new materials engineering method that has not yet been applied to phosphors materials. The proposer has performed preliminary experiments with very encouraging results. Successful results of this effort should be applicable to other display technologies including electroluminescent, AC plasma, and back lights for active matrix liquid crystal displays. It could also impact other applications that use phosphors such a fluorescent lighting. Improved power efficiency of ernissive displays. Improved power efficiency of fluorescent light sources.