Fabrication, microstructure, and temperature sensing behavior based on upconversion luminescence of novel Er³⁺,Yb³⁺ co-doped YOF ceramic

Novel YOF:Er,Yb ceramic was successfully fabricated by vacuum hot-press sintering method for the first time, and its phase, microstructure and upconversion luminescence were investigated. It was found that the ceramic showed very dense microstructure with few pores. Under 980 nm excitation, strong green (526 nm and 546 nm) and red (668 nm) upconversion emissions of Er³⁺ ions in the ceramic were observed. The upconversion mechanism was proposed based on the power dependence of the upconverted emissions. In addition, the temperature sensing behavior of the YOF:Er,Yb ceramic was investigated from 293 K to 873 K by using the fluorescence intensity ratio technique, and the maximum absolute sensitivity is 0.00882 K⁻¹ at 873 K and the maximum relative sensitivity is 1.35% K⁻¹ at 293 K. These results indicate that the fabricated YOF:Er,Yb ceramic is promising host material for optical temperature sensors.