Abstract
This paper describes the temperature dependence of up-conversion photoluminescence properties of co-doped Y_2O_3:Yb^<3+>/Er^<3+> phosphors. Y_2O_3:Yb^<3+>/Er^<3+> phosphors with various dopant concentrations were prepared by flame spray synthesis, and the photoluminescence spectra of prepared phosphors were examined in the temperature range from 300 K to 1100 K under the infrared excitation light. As a result, the intensity ratio between two emission lines was significantly changed with the temperature, and intensity ratios of all prepared phosphors coincided. regardless of the dopant concentration. Consequently, it is concluded that up-conversion Y_2O_3:Yb^<3+>/Er^<3+> phosphors can be useful for the phosphor thermometry.