Improving the temperature-sensing performance of the SrZn0.33Nb0.67O3:Pr3+ phosphor via Ga3+ doping

Abstract

Optical thermometry offers promising applications in the fields of microelectronics and biomedicine, as well as in fire pre-warning systems. In this research, Pr³⁺-activated SrZn_0.33Nb_0.67O₃ phosphors were successfully prepared via solid-state reactions. Under ultraviolet excitation, the SrZn_0.33Nb_0.67O₃:x%Pr³⁺ (x = 0.25/0.75/1.25/2) phosphors exhibit bright blue and red emissions, located at 491 nm (³P₀ → ³H₄), 619 nm (¹D₂ → ³H₄) and 651 nm (³P₀ → ³F₂). Specifically, two fluorescence intensity ratio (FIR) models of ¹D₂ → ³H₄versus³P₀ → ³H₄ (Red1/Blue) and ¹D₂ → ³H₄versus³P₀ → ³F₂ (Red1/Red2) in the temperature range of 300–500 K are adopted for temperature sensing. Our results show that the designed phosphor can serve as a novel potential self-calibrated optical thermometer. Moreover, the temperature sensitivity of the FIR thermometer is significantly enhanced when Ga³⁺ is incorporated into the SrZn_0.33Nb_0.67O₃. Specifically, the maximum absolute and relative sensitivity for the 6% Ga³⁺ co-doped sample are increased five- and two-fold, respectively, compared with the undoped sample. This work may provide useful inspiration for effectively improving the temperature-sensing performance of optical thermometers.