Near-infrared anti-Stokes luminescence from neodymium doped perovskite calcium titanate particles for optical temperature sensors

The optical thermometer materials have drawn tremendous attention for their excellent performances, such as fast response, well-adapted, and non-contact. However, most phosphors present thermally quenched emissions, which greatly weakens temperature sensing. In this work, we synthesized Yb3+/Nd3+ codoped CaTiO3 microcrystals by solid state reaction. Under the excitation of 980 nm, the developed perovskite particles present anti-Stokes emissions at the near-infrared range. More importantly, the near infrared anti-Stokes emissions gradually get enhanced as the temperature rises. An optical ratiometric thermometer has been constructed based on the energy level transitions of Nd3+ ions (F-4(7/2)/F-4(5/2) -> I-4(9/2)). On account of the thermally enhanced emissions, the prepared thermometer only needs 16 mW/mm(2) power density, and has a relatively high sensitivity of 1.52 % K-(1). Therefore, the prepared Yb3+/Nd3+ codoped CaTiO3 crystal is a promising optical thermometer material with great application prospects. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Yb3+/Nd3+ co-doped CaTiO3 microcrystals were synthesized and showed anti-Stokes emissions in the near-infrared range under 980 nm excitation, which increased with temperature. An optical ratiometric thermometer based on the energy level transitions of Nd3+ ions was constructed, with a high sensitivity of 1.52 % K^(-1).