Giant enhancement of anti-quenching upconversion luminescence in Sc2W3O12:Er3+/Yb3+ phosphors for temperature sensing

Abstract

Although negative thermal expansion (NTE) materials provide a new strategy to overcome the thermal-quenching phenomenon among rare earth doped luminescent materials, the overall weak upconversion luminescence still restricts their application in the field of optical temperature sensing. Herein, giant enhancement of anti-quenching upconversion luminescence is achieved in the NTE Sc₂W₃O₁₂:Er³⁺/Yb³⁺ phosphors by (KMg)³⁺ impurity doping, and the phosphors are used for the construction of an all-fiber temperature sensing (AFTS) system. Compared to the upconversion luminescence of the Sc₂W₃O₁₂:Er³⁺/Yb³⁺ phosphors at room temperature, the synergistic effect of impurity doping and NTE characterstics results in a 6000-fold enhancement of the upconversion luminescence of the (KMg)³⁺ doped Sc₂W₃O₁₂:Er³⁺/Yb³⁺ phosphors at 573 K. A single-point tip temperature sensor was constructed based on the fluorescence luminescence intensity ratio (FIR) technology and the corresponding self-calibrated curves were obtained with a regression coefficient of 0.9996. The potential application of the constructed AFTS system was demonstrated in the real-time temperature monitoring of a CPU chip and a thermostat bath.