Effect of Molten Salt on Synthesis and Luminescence Properties of YVO4:Eu3+ Red Phosphors

Abstract

Red phosphors YVO4:Eu3+ with high efficiency photoluminescence have been successfully synthesized using the molten salt synthesis (MSS) method, in which (Mg(NO3)2 ⋅ 6H2O, Ca(NO3)2 ⋅ 4H2O, Sr(NO3)2, and Ba(NO3)2) were used as the molten salt. These phosphors were characterized by powder X‑ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL). The results indicated that all phosphors showed rare earth Eu3+ ion characteristic emissions in the YVO4 host. The influence of adding molten salt on photoluminescence properties of YVO4:Eu3+ phosphors has been discussed. The red/orange (R/O) intensity ratio 5D0–7F2 to 5D0–7F1 values of Eu3+ of phosphors doped with different molten salts decreases in the order of Mg, Ca, Ba, Sr, which indicates that the red color of the light emitted by the material prepared using Mg(NO3)2 ⋅ 6H2O is the most pure. The most pure red light could be achieved from YVO4:Eu3+ phosphor with chromaticity coordinates of (0.64, 0.34) under excitation at 275 nm.