The present invention relates to a method of preparing a multilayer phosphor (film) product on a substrate. The method comprises adding solid particulate precursor to a solution of an alkoxide precursor and a dopant precursor before hydrolysis is allowed to occur. The mixture is then allowed to hydrolyze, resulting in a sol-gel condensation reaction. The solid particulate precursor can be fumed silica, and acts as a nucleation site for the sol-gel reaction product. After the sol-gel reaction, the mixture is dried and fired to form a multilayer phosphor (film). The phosphor film is especially suitable for applications in which there is low voltage operation.