Synthesis, structural and luminescence properties of near white light emitting Dy~(3+)-doped Y_2CaZnO_5 nanophosphor for solid state lighting

摘要

Novel near while light emitting Y_2CaZnO_5 (YCZ) nanocrystalline powders doped with Dy~(3+) 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 phololuminescence (PL), excitation spectra and decay time measurements. The PL spectra have shown a broad blue band due to ~4F_(9/2)→~6H_(15/2) transition and sharp yellow band corresponding to ~4F_(9/2)→~6H_(13/2) transition of Dy~(3+) ions. From the concentration dependent PL studies, the optimum concentration of Dy~(3+) ions in YCZ is found to be 1.0 mol%, where intense near white light emission was observed. The Dy~(3+) :YCZ nanophosphor has shown relatively better white color properties than the reported Dy~(3+):Y_2O_3 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.