Preparation and characterisation of Ce:YAG -polycarbonate composites for white LED

Abstract

Ce:YAG-polycarbonate composites were prepared with several amounts of Ce:YAG in the range 0.1–5 wt.% by using melt compounding. The structure and morphology of the composites were investigated by means of X-ray diffractometry and transmission electron microscopy. The optical properties of the composites were studied by using photoluminescence spectroscopy. The intermolecular interaction between the polymer and the filler surface was investigated using 13C cross-polarization magic-angle spinning NMR spectroscopy (13C {1H} CP-MAS NMR). The results showed that the dispersion of the particles in the polymer, and the optical properties, depend on the Ce:YAG amount. The composites were combined with a blue LED in order to test their performance in a white LED device. Results indicate that more suitable light is obtained using the Ce:YAG-PC composite loaded at 2 wt.%.