Photoluminescence enhancement of Y3Al5O 12:Ce nanoparticles using HMDS

Abstract

Coprecipitated Y3Al5O12:Ce (YAG:Ce) nanoparticles, treated with hexamethyldisilazane (HMDS) at 150°C for 1 h in an autoclave and then fired at 980°C, showed an enhanced photoluminescence (PL) intensity compared with pure YAG:Ce without any HMDS treatment. X-ray diffraction analysis revealed a shift of the (420) peak to a higher angle with more HMDS addition, indicating the decreasing lattice parameter caused by the substitution of Al3+ sites with Si4+ ions in the YAG host. Transmission electron micrographs showed a smaller size and more dispersal of YAG:Ce nanoparticles with more HMDS addition, which was caused by OH-scavenging methyl siloxyl groups. Diffuse reflectivity showed identical absorption behavior for pure and HMDS-treated YAG:Ce, suggesting the same amount of Ce3+ activators in the YAG host. Therefore, the enhancement of the PL intensity of HMDS-treated YAG:Ce was supposed to be a result of an increasing diffusion and a homogeneous distribution of Ce3+ activators in YAG, due to the smaller Si4+ ions and the formation of Al3+ vacancies, based on the longer decay time measured. © 2008 The American Ceramic Society.