Synthesis, structural and luminescence characterization of single phased Tm3+/Dy3+ co-doped Na3Y(VO4)2 nanocrystals

Abstract White light emitting Tm3+/Dy3+ co-doped α-Na3Y(VO4)2 nanocrystals were prepared via citrate based solution combustion route and systematic investigation on the structural and photoluminescence characterization was carried out. The photoluminescence studies of Tm3+/Dy3+ co-doped α-Na3Y(VO4)2 nanocrystals reveal the co-existence of characteristic emissions of Tm3+ and Dy3+ ions. By altering the ratio of Tm3+ and Dy3+ doping concentration, the emission colors can be tailored from blue to yellow through white light region. The systematic fall of emission intensity of Tm3+ ions and the rise of emission intensity of Dy3+ ions along with the decrease of lifetime of Tm3+ emission on increasing the Dy3+ content ascertain the energy transfer from Tm3+ to Dy3+ ions. The CIE chromaticity coordinates for α-Na3Y1-x-yTmxDyy(VO4)2 with x = 0.01 and with y = 0.002 or 0.003 are in close agreement with standard equal energy white light point. The calculated CCT values are 6172 K and 5510 K for the corresponding samples matches with the standard white light illumination (CCT = 5454.12K). These findings indicate that Tm3+/Dy3+ co-doped α-Na3Y(VO4)2 nanocrystals emerge as promising candidates for UV excitable phosphor converted white LED.