Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy
Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr<sub>3</sub> nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications. Clearly, there is a need for local and precise characterization techniques at the atomic scale, such as transmission electron microscopy. Because of the high electron beam sensitivity of MHPs, these investigations are extremely challenging. Here, we applied a low-dose method based on four-dimensional scanning transmission electron microscopy. We quantified the observed elongation of the projections of the Br atomic columns, suggesting an alternation in the position of the Br atoms perpendicular to the Pb-Br-Pb bonds. Together with molecular dynamics simulations, these results remarkably reveal local distortions in an on-average cubic structure. Additionally, this study provides an approach to prospectively investigating the fundamental degradation mechanisms of MHPs.
Authors
- Johan Verbeeck (ORCID: https://orcid.org/0000-0002-7151-8101)
- Nikolaos Livakas (ORCID: https://orcid.org/0000-0002-5387-9894)
- Sara Bals (ORCID: https://orcid.org/0000-0002-4249-8017)
- Nadine J. Schrenker (ORCID: https://orcid.org/0000-0002-3667-4440)
- Tom Braeckevelt (ORCID: https://orcid.org/0000-0002-9669-3715)
- Annick De Backer (ORCID: https://orcid.org/0000-0002-8592-4776)
- Thomas Friedrich (ORCID: https://orcid.org/0000-0002-7584-2080)
- Liberato Manna (ORCID: https://orcid.org/0000-0003-4386-7985)
- Johan Hofkens (ORCID: https://orcid.org/0000-0002-9101-0567)
- Véronique Van Speybroeck (ORCID: https://orcid.org/0000-0003-2206-178X)
- Maarten B. J. Roeffaers (ORCID: https://orcid.org/0000-0001-6582-6514)
- Sandra Van Aert (ORCID: https://orcid.org/0000-0001-9603-8764)
- Chu-Ping Yu (ORCID: https://orcid.org/0000-0003-1563-5095)
Institutions
- University of Antwerp (BE)
- Italian Institute of Technology (IT)
- Ghent University (BE)
- University of Genoa (IT)
- KU Leuven (BE)
Publication Details
- Journal
- Nano Letters
- Published
- 2024-08-20
- DOI
- https://doi.org/10.1021/acs.nanolett.4c02811
- Citations
- 10
- Primary Topic
- Perovskite Materials and Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.09
Funders
- Vlaams Supercomputer Centrum
- European Commission
- Fonds Wetenschappelijk Onderzoek
- Universiteit Gent
- Vlaamse regering
- H2020 European Research Council