Luminescence characteristics and low temperature optical temperature measurement of Pr3+ doped Sr2NaMg2V3O12 phosphors

A series of Pr3+ doped Sr2NaMg2V3O12 (SNMV) garnet phosphors were successfully synthesized by high temperature solid state method. The crystal structure, luminescent properties and temperature sensing properties of the phosphors were systematically studied. Under the excitation of 339nm, SNMV:Pr3+ phosphors exhibit strong blue-green broadband emission in the wavelength range of 400-700nm and typical red emission of Pr3+ at 612nm and 624nm, which correspond to the energy level transition of [VO4]3- group and 1D2→3H4,5 transition of Pr3+, respectively. Furthermore, in the temperature range of 98K-298K, high sensitivity optical temperature sensing is realized based on fluorescence intensity ratio (FIR) and fluorescence lifetime (FL). In FIR mode, the maximum absolute sensitivity (Sa) and relative sensitivity (Sr) of the phosphor are 0.01782K-1 (298K) and 1.13543%K-1 (298K), respectively. In FL mode, the maximum Sa value and Sr value are 0.0889K-1 (198K) and 0.62752%K-1 (223K), respectively. The results show that SNMV:Pr3+ phosphors have great potential in the field of optical temperature measurement.