Ratiometric temperature sensing based on non-thermal coupling levels in BaZrO3: Yb3+/Er3+ ceramics

High sensing sensitivity and accuracy is valuable for optical temperature sensors in practical applications. Er3+/Yb3+ co-doped BaZrO3 ceramics were prepared by the dry pressing method. The upconversion luminescence of Er3+/Yb3+ co-doped BaZrO3 ceramics was studied at a temperature range from 300 to 500 K under different pump power. The ratio of non-thermal coupling levels of 4S3/2, 4I9/2→4I15/2 (I546/I875), and 4F9/2, 4I9/2→4I15/2 (I658/I875) show a linear relationship as the temperature increased. The maximum relative sensitivity was estimated to be 1.39% K−1 at 500 K under 90 mW pump power. The result indicated that the BaZrO3:Er3+/Yb3+ ceramic is a promising candidate for high temperature sensing applications.