Calibration of optical temperature sensing of Ca1-xNaxMoO4:Yb3+,Er3+ with intense green up-conversion luminescence

High luminescence intensity is crucial for realizing luminescent temperature sensing with a large signal-to-noise ratio. In this work, the temperature sensing behavior of Ca1-xNaxMoO4:Yb3+,Er3+ with intense green up-conversion luminescence was studied. It has been demonstrated that the single-band green emission was dependent on the Yb3+-MoO42- dimer sensitization as well as the low multi-phonon relaxation rate of 4S3/2 → 4F9/2. In addition, it was found that the uncorrected thermometer could not accurately measure temperature due to thermal effects. A simple method for calibration of up-conversion temperature sensing was reported. Due to high luminescence intensity and temperature sensitivity, Ca1-xNaxMoO4:Yb3+,Er3+ is a promising candidate for up-conversion temperature sensing.