Preparation, Photoluminescence, and Photostability of Transparent Composite Films of Glycothermally Synthesized YAG:Ce3+Nanoparticles for White LED

The powder of glycothermally synthesized, Ce3+-doped yttrium aluminum garnet (YAG:Ce3+) nanoparticles exhibits decreased green-yellow emission, under continuous blue light excitation. This emission corresponds to the 5d → 4f transition of Ce3+. YAG:Ce3+ nanoparticles were dispersed in polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) matrix films, to improve their photostabilities. The well-dispersed YAG:Ce3+ nanoparticles were confirmed from transmission electron microscopy observations. The emission and excitation spectra of the composite films were comparable to those of the YAG:Ce3+ nanoparticle powder. The photoluminescence (PL) intensity of the YAG:Ce3+/PVP film gradually decreased to 35% of its initial PL intensity, upon exposure to excitation at 450 nm. The PL intensity of the YAG:Ce3+/PVA film recovered to 95%, after initially decreasing to 82%. The differing photostabilities of the two composite films are discussed.