Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy
Year: 2016
Type: article
Abstract: We report on an element-selective study of the fate of charge carriers in photoexcited inorganic CsPbBr3 and CsPb(ClBr)3 perovskite nanocrystals in toluene solutions using time-resolved X-ray absorption spectroscopy with 80 ps time resolution. Probing the Br K-edge, the Pb L3-edge, and the Cs L2-edge, we find that holes in the valence band are localized at Br atoms, forming small polarons, while electrons appear as delocalized in the conduction band. No signature of either electronic or structural changes is observed at the Cs L2-edge. The results at the Br and Pb edges suggest the existence of a weakly localized exciton, while the absence of signatures at the Cs edge indicates that the Cs+ cation plays no role in the charge transport, at least beyond 80 ps. This first, time-resolved element-specific study of perovskites helps understand the rather modest charge carrier mobilities in these materials.
Source: Structural Dynamics
DOI: 10.1063/1.4971999
Authors: Fabio G. Santomauro, Jakob Grilj, Lars Mewes, Georgian Nedelcu, Sergii Yakunin, Thomas Rossi, Gloria Capano, André Al Haddad, James Budarz, Dominik Kinschel, Dario S. Ferreira, Giacomo Rossi, Mario Gutierrez Tovar, Daniel Grolimund, Valerie Samson, Maarten Nachtegaal, Grigory Smolentsev, Maksym V. Kovalenko, Majed Chergui
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,200
Awards: Nanomaterial Synthesis using Intelligent Microfluidics, G2001806450, G3201539754, G3345895242, Interplay of charge, spin and structural dynamics of metal complexes in solution: Ultrafast optical and core-level spectroscopy studies, Nanophotonics by Nanocrystals, from integration to single photon operation, G6530356953, G708664468, G7984235579, G8211335943, G8512683158, Preparation and characterization of high efficiency hybrid organic-inorganic thin film solar cells
OpenAlex ID: W2531253191