Luminescence upconversion of Er:Yb:KY(WO4)2 green phosphor with high color purity

Green phosphors Er:Yb:KY(WO4)2 doped with various Er3+ and Yb3+ concentrations were synthesized by the modified Pechini method. Cell parameters evolution was evaluated by Rietveld refinement. Stokes spectra at 514 nm of samples were dominated by Er3+ and Yb3+ luminescence. Samples under 980 nm exhibited strong upconversion emission at 530 nm and 550 nm and low 660 nm emission for different Er3+ and Yb3+ concentrations. Luminescence dynamics of Er3+ and Yb3+ ions has been described by analysing upconversion emission intensity dependence on the excitation power, as well as from Stokes emission and decay time measurements. Based on 1931 CIE chromaticity calculations as coordinates, dominant wavelength and color purity, Er:Yb:KY(WO4)2 was suggested as a possible green phosphor for technological applications.