Fluorescence Lifetime-Based Luminescent Thermometry Material with Lifetime Varying over a Factor of 50.

Recently, the growing demand for temperature detection is pushing forward the flourishing development of noncontact optical thermometry. Herein, a new red phosphor Sr 2 InTa 1- x O 6 : x Mn 4+ (SIT: x Mn 4+ ) was first constructed and systematically investigated. Based on the fairly rapid decline of the lifetime from 0.403 to 0.008 ms by increasing the temperature from 25 to 450 K, a noncontact optical thermometer can be made from phosphor SIT:0.003Mn 4+ with S r = 1.396% K -1 at 375 K and S a = 0.0012 K -1 at 300 K. Because the luminescence is based on the outermost 3d orbits of Mn 4+ , the lifetime of SIT: x Mn 4+ is quite sensitive to the temperature, leading to a rapid decline of the lifetime with the increase in temperature. Moreover, multiple rounds of variable-temperature studies were performed to demonstrate the stability and reversibility of SIT:0.003Mn 4+ . This work suggests that Mn 4+ -phosphors are promising candidates for application as optical thermometric material.