Control of Hot Carrier Relaxation in CsPbBr3 Nanocrystals Using Damping Ligands

Abstract

AbstractIn photon‐conversion processes, rapid cooling of photo‐induced hot carriers is a dominant energy loss channel. We herein report a 3‐fold reduced hot carrier cooling rate in CsPbBr3 nanocrystals capped with a cross‐linked polysiloxane shell in comparison to single alkyl‐chain oleylamine ligands. Relaxation of hot charge carriers depends on the carrier‐phonon coupling (CPC) process as an important channel to dissipate energies in nanostructured perovskite materials. The CPC strengths in the two samples were measured through cryogenic photoluminescence spectroscopic measurements. The effect of organic ligands on the CPC in CsPbBr3 nanocrystals is elucidated based on a damped oscillation..