Abstract

Nanocrystalline powder of (Tm³⁺,Yb³⁺):KLu(WO₄)₂ doped with different concentrations of Ho³⁺, was synthesized by the modified Pechini method. Powder X-ray diffraction, transmission electron microscopy, upconversion photoluminescence and room-temperature kinetic decay measurements were used to characterize the samples. The nanocrystals possess the monoclinic symmetry of the C2/c space group. The crystallite size was in the range of 30-70 nm. Under 930 nm laser excitation, red, green and blue upconversion emissions were simultaneously observed, due to the energy transfer from the Yb^{3+ 2}F_5/2 excited level. The decay times of the emitting states were studied at room temperature to describe the photoluminescence dynamics. The influence of excitation power and calcination conditions on CIE chromaticity coordinates was evaluated.

© 2011 Optical Society of America