A novel optical temperature sensor based on Boltzmann function in BiZn2PO6 phosphor

In this paper, a new scheme of optical temperature measurement based on Boltzmann function is reported for the first time. The BiZn 2 PO 6 and BiZn 2 PO 6 :Eu 3+ phosphors with strong host emission intensity were investigated from the perspective of crystal structure, electronic band structure , phonon distribution, and fluorescence properties. By exploring the relationship between host emission intensity and temperature, or between fluorescence lifetime and temperature, a novel optical temperature sensor based on Boltzmann function was designed. With this scheme, the performance of the optical temperature sensors can be visualized in the fitting results of Boltzmann function. The absolute sensitivity of the optical temperature sensor designed based on this function reaches a maximum value S a = 1 4 d T $S_a=\frac{1}{4dT}$ at T 0 $T_0$ , while relative sensitivity is 1 2 d T $\frac{1}{2dT}$ . For example, in BiZn 2 PO 6 phosphor, the absolute and relative sensitivities reached 0.88% and 1.78% at 260 K. Therefore, the new optical temperature sensor based on Boltzmann function provides the theoretical basis and practical experience for the development of high-sensitivity non-contact optical temperature sensor.