A multi-mode self-referenced optical thermometer based on low-doped YVO4: Eu3+ phosphor

Abstract

In recent years, the continued development of optical thermometry has become a hot topic of interest for researchers, due to its advantages of non-contact and non-invasive temperature measurement. The optical thermometry is based on the different photophysical properties or changes in luminescent parameters of luminescent materials to reflect temperature. Further, the development of multi-mode optical thermometers can effectively expand the practical application rang of the temperature measurements. Here, we monitored various temperature sensitive luminescence characteristics of YVO4: Eu3+ phosphor by testing its temperature-dependent photoluminescence (PL) spectra, photoluminescence excitation (PLE) spectra, and luminescence decay curves. We successfully realized a multi-mode optical thermometer based on the luminescence intensity ratio, absorption intensity ratio, the thermally induced behavior of the charge transfer band, and luminescent transition probability (A) of the host material. Different temperature measurement strategies were evaluated and compared in terms of relative sensitivity (Sr) and temperature uncertainty (ΔT). Notably, the Sr of the rarely used temperature measurement strategy based on the A of host luminescence was the optimal among the studied strategies with 2.03% K−1, corresponding to a ΔT of 0.5 K. The results suggest that YVO4: Eu3+ phosphor has potential applications in self-referential optical thermometry.