Synthesis, structural and luminescence properties of near white light emitting Dy3+-doped Y2CaZnO5 nanophosphor for solid state lighting

Novel near white light emitting Y2CaZnO5 (YCZ) nanocrystalline powders doped with Dy3+ ions were synthesized via the citrate gel combustion method. The structure of the compound is found to be triclinic with a particle size in the range of 20-30 nm. Luminescence properties have been characterized using photoluminescence (PL), excitation spectra and decay time measurements. The PL spectra have shown a broad blue band due to 4F9/2→6H15/2 transition and sharp yellow band corresponding to 4F9/2→6H13/2 transition of Dy3+ ions. From the concentration dependent PL studies, the optimum concentration of Dy3+ ions in YCZ is found to be 1.0 mol%, where intense near white light emission was observed. The Dy3+:YCZ nanophosphor has shown relatively better white color properties than the reported Dy3+:Y2O3 nanophosphor. The yellow to blue intensity ratios, CIE chromaticity coordinates and correlated color temperature studies have shown the possibility of using this compound for white light emission.