Thermally robust up-conversion emission in LuTaO4:Er3+, Yb3+ system for optical thermometry application

Yb 3+ /Er 3+ -doped up-conversion materials have been widely used in many fields due to high up-conversion efficiency in the visible region. However, it is still challenging to achieve high thermal stability in Yb 3+ /Er 3+ system owing to the non-radiative relaxation. Herein, Er 3+ and Yb 3+ co-doped LuTaO 4 phosphor is synthesized via a high-temperature solid-state method, and we successfully apply the phosphor into ceramic. The integrated emission intensity of the green luminescence could maintain 87.1% of initial intensity at 418 K. Besides, the peaks located at 521 nm and 528 nm achieve anti-thermal-quenching performance, showing an enhancement of 2.28 times and 2.13 times at 418 K, respectively. Based on the optical characterization and fluorescence intensity ratio calculation, a relative sensitivity of 1.432% K −1 at 298 K and an absolute sensitivity of 0.4757% K −1 at 538 K are achieved. In addition, the prepared ceramics also exhibit excellent thermal stability and FIR sensitivity. This work initiates a feasible strategy to accelerate the development of up-conversion luminescent phosphors with excellent thermal stability.