The effect of flux materials on the physical and optical properties of Eu3+-activated yttrium oxide phosphors

A flux fusion method was used to obtain the various sizes of Eu3+-activated Y2O3 red phosphors. The flux material was selected as an independent variable to control the physical properties of phosphor particles and their effects on the morphology and size distribution of phosphors were examined by scanning electron microscopy. The concentration of the flux materials and synthetic temperature were optimized for maximal photoluminescence intensity. Fluoride-based flux materials were found to work for the crystal formation of Eu3+-activated Y2O3. In particular, when a BaF2 flux was used during the reaction at 1450 deg. C for 3 h, the photoluminescence (PL) intensity of Eu3+-activated Y2O3 was 25% higher than that without a flux and spherical phosphors had a mean particle size of 4-5 μm. The morphology and size distribution of the synthesized Eu3+-activated Y2O3 phosphor were predominantly dependent upon the type and concentration of flux material and synthetic temperature.