Stably and highly sensitive FIR thermometry over a wide temperature range of 303-753 K based on the GdVO4:Eu3+ and Al2O3:Cr3+ hybrid particles.

Abstract

Fluorescence intensity ratio (FIR) temperature sensors provide an effective method to control or study fine variations in physical and biological research because of their high sensitivity, accuracy, and spatial resolution. However, it is difficult to maintain high sensitivity over a wide temperature range using FIR temperature sensors because of the limits of the Boltzmann distribution law. In this study, sensitivity amplification for a wide temperature range in FIR thermometry based on GdVO4:Eu3+ and Al2O3:Cr3+ hybrid particles is achieved. The mechanism of the non-monotonic temperature dependence of the relative sensitivity (Sr) is studied. The results demonstrate that the Sr stably keeps ∼2.4% per K over a wide temperature range of 303-753 K, thus providing a basis for the extensive application of FIR temperature sensors.