Preparation of NaSrLa(WO4)3:Ho3+/Yb3+ ternary tungstates and their upconversion photoluminescence properties

NaSrLa1-x(WO4)(3):Ho3+/Yb3+ ternary tungstates were synthesized via microwave sol-gel route. Well crystallized particles with particle sizes of 2-5 mu m were obtained after heat-treatment at 900 degrees C for 16 h. Under the excitation at 980 nm, the particles showed yellow emissions based on the strong 545 and 655 nm emission bands. The preferable Yb3+:Ho3+ ratio was obtained to be 9:1. Raman spectra of the doped particles indicated the presence of strong Ho3+ luminescence lines. The pump power dependence and Commission Internationale de L'Eclairage chromaticity of the upconversion emission intensity were evaluated. (C) 2016 Published by Elsevier B.V.