Nd3+/Yb3+ codoped SrWO4 for highly sensitive optical thermometry based on the near infrared emission

In this paper, Nd3+/Yb3+ codoped SrWO4 phosphors for temperature sensing are investigated. Firstly, the doping ratio of Nd3+ and Yb3+ was optimized. Then, under a 980 nm excitation, the temperature response of the near infrared (NIR) upconversion emission spectra in the temperature range of 313 K-453 K was characterized. The results show that the NIR emission peaks increase notably with the increase of temperature. With the fluorescence intensity ratio (FIR) technique, thermal sensing property of the optimized phosphor was investigated. A maximum thermal sensitivity of 0.02857 K−1 (I801/I869) at 453 K was achieved, which is higher than that of the other previously reported similar materials. The minimum temperature uncertainty is about 1 K at 453 K. The results reveal that SrWO4: Nd3+/Yb3+ is a promising material for optical thermometry.