High-sensitivity Eu3+/Mn4+co-doped Li4AlSbO6 perovskite type thermometry with efficient dual emission

Optical temperature sensors based on photoluminescent materials have received extensive attention for their non-contact superiority. The traditional optical thermometry usually utilizes rare earth doped phosphors with thermal coupling levels to realize Boltzmann equilibrium. However, high temperature sensitivity and good signal resolution cannot be satisfied at the same time based on this strategy due to the photoluminescence quenching at high temperature. Herein, Eu3+/Mn4+ co-doped Li4AlSbO6 double perovskite phosphor is introduced as recommendable optical thermometry. Under 465 nm blue light excitation, the phosphor exhibits Eu3+ (611.5 nm) and Mn4+ (675 nm) emissions in the red and near-infrared ranges, respectively. Due to the different temperature-dependence optical behaviors of Mn4+ and Eu3+ in the range of 80 K-460 K. The highest relative sensitivity Sr of LIR based on 2E -4A2 (675 nm)/5D0-7F2 (611.5 nm) was 2.47% K-1. In addition, the highest absolute sensitivity Sa and relative sensitivity Sr obtained based on the average decay lifetime ratio of Mn4+ and Eu3+ are 0.134 K-1 and 3.07% K-1, respectively. These results indicate that Eu3+/Mn4+ co-doped Li4AlSbO6 is one kind of remarkable optical thermometry with high sensitivity.