Doping Level Effect on the Luminescence Efficiency of Tb3+/Tb4+-Doped BaWO4 Phosphors Prepared by a Sol-Gel Process

Background: Rare earth ions in many matrices can emit various luminescences under ultraviolet and/or infrared excitation and so have widely studied for many luminescence applications such as in fluorescent lamps, cathode ray tubes, X-ray intensifying screens, etc. Terbium (Tb) ion is commonly one of the trivalent rare earth ions and widely used for green phosphors material. Method: The Tb-doped BaWO4 phosphor powders with Tb content of 0–7.5 at.% were fabricated with a sol-gel method. X-ray diffraction analysis, scanning electron microscopy, and photoluminescence spectra analysis were used to characterize the microstructural and photoluminescence efficiency. Conclusion: The effect of Tb doping level was studied. Granular particle morphology and decreased nano-scale average particles size with increasing Tb-doping level were observed. The Tb3+/Tb4+ in the BaWO4 matrix showed green emission with cool color temperature of 12764 K. A maximal doping level of Tb3+/Tb4+ cation was observed for a highest emission efficiency of Tb3+/Tb4+ cation.