Pressure Effect on Self-Trapped Exciton and Dopant Energy Transfer in Neodymium-Doped CsPbBr₃ Perovskite Nanocrystals

Abstract

The CsPbBr3 nanocrystal is a highly attractive light emitter with outstanding monochromaticity and good thermal stability and has garnered tremendous interest in its application in luminescent materials and devices. Here, we propose a novel strategy to improve the luminescence intensity of CsPbBr3 nanocrystals by doping with Nd3+ ions and introducing pressure. Under high pressure, the CsPbBr3:Nd nanocrystals show an abnormal enhancement of the photoluminescence intensity from 0.19 to 0.34 GPa. The time-resolved photoluminescence measurements reveal that pressure facilitates the recombination of self-trapped excitons and suppresses the recombination of the Nd energy levels. This discovery shows that pressure can modulate the photoluminescence kinetics of CsPbBr3:Nd nanocrystals. This work deepens the understanding of the influence of high pressure on rare-earth-doped luminescent materials and provides insight to improve the capabilities of optical devices.