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

Abstract

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