Ultrahigh-sensitive optical temperature sensing in Pr3+:Y2Ti2O7 based on diverse thermal response from trap emission and Pr3+ red luminescence

In this work, a new optical thermometer relying on highly temperature-dependent 1D2 Pr3+ emission and temperature insensitive Y2Ti2O7 trap emission is reported. Based on the fluorescence intensity ratio (FIR) between them, Pr3+: Y2Ti2O7 with remarkably high absolute and relative sensitivities of ~ 983 × 10−4 K−1 and 5.25% K−1 as well as good signal discriminability is realized. It also exhibits a tunable luminescent color from red to purplish blue with temperature from 289 to 573 K. The strong thermal quenching of 1D2 Pr3+ emission is mainly related to the charge transfer state (CTS). Similarly, Pr3+: Gd2Ti2O7 phosphor also demonstrates a favorable temperature sensing feature, indicating the temperature sensing strategy based on the combination of host trap emission and CTS interfered Pr3+ luminescence is a promising pathway to develop high-performance optical thermometric materials.