Real-time observation of the buildup of polaron in α-FAPbI3

Nat Commun. 2023 Feb 17;14(1):917. doi: 10.1038/s41467-023-36652-4.


The formation of polaron, i.e., the strong coupling process between the carrier and lattice, is considered to play a crucial role in benefiting the photoelectric performance of hybrid organic-inorganic halide perovskites. However, direct observation of the dynamical formation of polarons occurring at time scales within hundreds of femtoseconds remains a technical challenge. Here, by terahertz emission spectroscopy, we demonstrate the real-time observation of polaron formation process in FAPbI3 films. Two different polaron resonances interpreted with the anharmonic coupling emission model have been studied: P1 at ~1 THz relates to the inorganic sublattice vibration mode and the P2 at ~0.4 THz peak relates to the FA+ cation rotation mode. Moreover, P2 could be further strengthened than P1 by pumping the hot carriers to the higher sub-conduction band. Our observations could open a door for THz emission spectroscopy to be a powerful tool in studying polaron formation dynamics in perovskites.

PMID:36801865 | PMC:PMC9938110 | DOI:10.1038/s41467-023-36652-4


Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *

Generated by Feedzy