Effect of Tm3+ Concentration and Temperature on Blue and NIR Upconversion Luminescence in Tm3+/Yb3+ Co-Doped NaY(WO4)(2) Microstructures

摘要

Tm3+/Yb3+ codoped NaY(WO4)(2) microstructures with various Tm3+ concentrations and 10 mol% Yb3+ concentration were prepared by a microwave-assisted hydrothermal method, and their upconversion luminescence (UCL) was investigated. Under excitation at 980 nm, Tm3+/Yb3+ codoped NaY(WO4)(2) exhibited strong blue and near infrared (NIR) emissions, respectively, corresponding to (1)G(4) -> H-3(6) and H-3(4) -> H-3(6) transitions, with weak red emission due to the (1)G(4) -> H-3(4) transition. The optimum doping concentrations of Tm3+ for the highest blue and NIR UCL were investigated, and it was found that the optimal concentrations for blue and NIR emissions were 0.5 mol% and 1.5 mol%, respectively. In addition, an analysis of temperature dependent blue and NIR UCL in both the samples with low and high Tm3+ concentrations, respectively, was undertaken. The results implied that the sample with low Tm3+ concentration displayed more obvious effect on the thermal quenching of (1)G(4) level.