Journal of Advanced Ceramics


phosphors, scheelite structure, luminescence property, anion substitution


Novel scheelite structures of Li2Ca(WO4)2, Li2Ca2(WO4)(SiO4), and LiCa2(WO4)(PO4) fluorescent materials were successfully prepared using a high-temperature solid-phase process. The compounds were characterized by X-ray diffraction and energy dispersive spectroscopy. The tests revealed that the substitution of [WO4]2- by [SiO4]4- or [PO4]3- tetrahedron in tungstate had no significant influence on the crystal structure of the Li2Ca(WO4)2. When Dy3+ ions were introduced as an activator at an optimum doping concentration of 0.08 mol%, all of the as-prepared phosphors generated yellow light emissions, and the emission peak was located close to 576 nm. Replacing [WO4]2- with [SiO4]4- or [PO4]3- tetrahedron significantly increased the luminescence of the Li2Ca(WO4)2 phosphors. Among them, the LiCa2(WO4)(PO4):0.08Dy3+ phosphor had the best luminescence properties, decay life (τ = 0.049 ms), and thermal stability (87.8%). In addition, the as-prepared yellow Li2Ca(WO4)2:0.08Dy3+, Li2Ca2(WO4)(SiO4):0.08Dy3+, and LiCa2(WO4)(PO4):0.08Dy3+ phosphor can be used to fabricate white light emitting diode (LED) devices.