Up- conversion luminescence of rare earth- doped KGd(WO4)(2) phosphors for tunable multicolour light generation

摘要

A series of novel KGd(WO4)(2) crystalline powders doped with Yb3+/Tm3+, Yb3+/Er3+ and Yb3+/Ho3+ were synthesized using a modified Pechini method. The monoclinic structure of these compounds was confirmed by XRD. The luminescence properties were investigated by measuring up-conversion luminescence spectra and decay curves. KGd(WO4)(2) crystalline powders doped with Yb3+/Tm3+, Yb3+/Er3+ and Yb3+/Ho3+ exhibit effective multicolour up-conversion luminescence in the VIS and NIR spectral ranges under 980 nm excitation. The vibrational properties of the materials were investigated using m-Raman spectroscopy. The assistance of low energy phonons of the KGd(WO4)(2) matrix in the energy transfer processes between the excited manifolds of the Yb3+, Er3+, Tm3+ and/or Ho3+ ions during the up-conversion process was discussed. These results indicate that KGd(WO4)(2) powders doped with selected Tm3+, Er3+, Ho3+ and Yb3+ ions may be potentially used as single-component multicolour or white emission phosphors.