Photoluminescence Property of Nano Silica Mixed YAG:Ce Phosphors

Typical white light-emitting diode (LED) lighting is made by combining blue LED for excitation and yellow phosphor, which absorb blue light and emit yellow light. One way to further improve the performance of white LED lighting is to improve the quantum efficiency of the yellow phosphor. A common method to improve the quantum efficiency of phosphors is to coat the phosphor surface with an oxide material. Therefore, increasing the surface area of the phosphors, followed by mixing with nano-silica, would be effective in further improving the quantum efficiency of the phosphors. In this study, yttrium aluminum garnet (YAG) powder, which is widely used as a yellow phosphor for white LED lighting, was pulverized by ball milling and composite YAG powders mixed with nano-silica prepared in a tetraethyl orthosilicate (TEOS) solution at room temperature was evaluated. We obtained smaller particles by ball milling. In addition, the composite YAG powders were successfully fabricated without changing the emission spectrum of YAG, but quantum efficiency was unchanged or decreased due to the non-uniform silica powders on YAG particles.