A method for making a phosphor composition is provided. The method includes the steps of providing a first phosphor comprising a visible-light-emitting phosphor; providing a second phosphor having an average primary crystallite size of less than about 100 nm and disposing the second phosphor onto to the first phosphor. The second phosphor includes at least one phosphor selected from a group consisting of a visual light emitting phosphor, ultraviolet (VUV) light emitting phosphor and a quantum splitting phosphor.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH & DEVELOPMENT
 This invention was made with Government support under contract number DE-FC26.03NT41945 awarded by the Department of Energy. The Government has certain rights in the invention.