A High-Precision Fluorescence Temperature Sensor Based on Er3+-/Yb3+-Doped KYW2O8 Phosphors

A high-precision ratiometric fluorescence temperature sensor was constructed and used to achieve the real-time chip temperature monitoring. Intense green fluorescence signals at 535 nm and 557 nm were observed in KYW2O8:Er3+/Yb3+ phosphors at a low energizing power of 1.5 mW. The calibration curve between fluorescence intensity ratio (FIR) of two green fluorescence signals and temperature was built at the temperature range of 253 similar to 423 K. The fitted regression coefficient was 0.999. The maximum absolute and relative temperature sensitivity S-a and S-r are 0.0115 K-1 at 423 K and 0.0145 K-1 at 253 K, respectively. The temperature measurement error is only +/- 0.2 K. Six round cyclic heating and cooling test indicates the built fluorescence temperature sensor exhibits good repeatability and could realize real-time and accurate measurement of chip temperature.