Temperature-dependent luminescence of a phosphor mixture of Li2TiO3: Mn4+ and Y2O3: Dy3+ for dual-mode optical thermometry

Mixture of Mn4+-doped phosphor (Li2TiO3:Mn4+) and Dy3+-doped phosphor (Y2O3: Dy3+) were prepared and investigated for the application of optical thermometry. X-ray powder diffraction and luminescence spectroscopy measurements were performed on all samples to analysis their optical properties. In particular, temperature-dependent luminescence and fluorescence lifetime of the mixture sample were measured in the temperature range of 273–373 K. Further analysis showed that the mixture sample used for temperature sensing has an excellent relative sensitivity with maximum value of 4.34% K−1 at 288 K based on fluorescence intensity ratio (FIR) and 6.67% K−1 at 339 K based on fluorescence lifetime, respectively. All these investigations suggest that the mixture phosphor is very promising in dual-mode high-sensitivity optical thermometry.