Structural and luminescent performance and optical thermometry of Pr3+ doped SrWO4 down-conversion phosphors.

A series of Pr3+ doped SrWO 4 phosphors were synthesized using solid-state reaction routes. The phase composition, photoluminescence and temperature sensitivities of as-prepared materials were investigated. Rietveld refinement of measured XRD data was applied to analyze the lattice parameters. The optical transition was elaborated using UV–visible diffuse reflectance spectra and photoluminescence spectra. The photoluminescence measurements confirmed the strong visible light emission from the developed phosphors under both UV excitation at 250 nm and blue excitation at 450 nm. Notably, the maximum emission intensity was observed at a Pr3+ doping concentration of 2 mol%. Furthermore, the fluorescence intensity ratio (FIR) technique was employed, focusing on the emissions originating from the 3P 0 and 1D 2 state of Pr3+ within the temperature range of 298–598 K. Two FIR groups were adopted in this case, which can verify each other to achieve self-calibration. Typically, SrWO 4 :0.02Pr3+ exhibited remarkable performance as a temperature sensor, displaying an absolute sensitivity (Sa) of 3.11%K−1 and a relative sensitivity (Sr) of 0.81%K−1. As a result, the significant temperature-dependent PL and remarkable down-conversion luminescence make the SrWO 4 :Pr3+ material a promising candidate for optical thermometers and UV to visible converters of solar cell applications. • Intense visible emission of SrWO 4 :Pr3+ excited by 250 nm and 450 nm was observed. • FIR from non-thermally coupled energy levels was used for temperature sensing. • The wide-range and highly-sensitive of optical temperature sensing were realized. • The self-calibration of temperature measurement was achieved by two FIR groups. [ABSTRACT FROM AUTHOR]