Title | Deciphering the emission of lead halide perovskites: insights from single CsPbBr3 nanocrystal studies
Date | Monday, June 1, 2024, at 9:30 a.m. (UTC +2)
Speaker | M.-R. Amara (Laboratoire de Physique de l’Ecole Normale Supérieure (LPENS), Centre Nationale
de la Recherche Scientifique (CNRS))
Abstract |
Lead halide perovskite NCs (LHP NCs) are promising materials for light emission. A
better understanding of their outstanding properties in ensemble and roomtemperature
studies is complicated by broadening and averaging effects. Single NC
studies thus offer a unique probe to the band-edge electronic structure, fuelling
debates on the importance of the Rashba effect and its impact on brightness.
With cryogenic-temperature spectral studies, the size-dependent excitonic features
as well as the optical phonon replica spectrum were revealed, supporting a
predominant influence of electron-hole exchange interaction and rationalising the
variety of single NC spectra recorded.
In the temporal domain, the temperature evolution of the photoluminescence
elucidates the interplay between bright and dark exciton states, revealing reduced
bright-dark conversion characteristic of lead halide perovskites. This accounts for the
predominant bright exciton emission at all temperatures, contrasting with established
II-VI nanocrystals.
Overall, we show how single NC studies, both in the spectral and temporal domain,
have enhanced our understanding of the electronic structure and luminescence
mechanisms of lead halide perovskites.
Our contributions :
M.-R. Amara et al., Nano Letters 23(8) 3607 (2023)
M.-R. Amara et al., Nano Letters 24(14) 4265 (2024)
