Abstract
Despite broad interest in colloidal lead halide perovskite nanocrystals (LHP NCs), their intrinsic fast growth has prevented controlled synthesis of small, monodisperse crystals and insights into the reaction mechanism. Recently, a much slower synthesis of LHP NCs with extreme size control has been reported, based on diluted TOPO/PbBr2 precursors and a diisooctylphosphinate capping ligand. We report new insights into the nucleation, growth, and self-assembly in this reaction, obtained by in situ synchrotron-based small-angle X-ray scattering and optical absorption spectroscopy. We show that dispersed 3 nm Cs[PbBr3] agglomerates are the key intermediate species: first, they slowly nucleate into crystals, and then they release Cs[PbBr3] monomers for further growth of the crystals. We show the merits of a low Cs[PbBr3] monomer concentration for the reaction based on oleate ligands. We also examine the spontaneous superlattice formation mechanism occurring when the growing nanocrystals in the solvent reach a critical size of 11.6 nm.
Original language | English |
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Pages (from-to) | 667-676 |
Number of pages | 10 |
Journal | Nano Letters |
Volume | 23 |
Issue number | 2 |
DOIs | |
Publication status | Published - 25 Jan 2023 |
Bibliographical note
Publisher Copyright:© 2023 The Authors. Published by American Chemical Society.
Funding
F.M. acknowledges support from ETH Zürich via an ETH Postdoctoral Fellowship (FEL-15 18-2) and from the Marie Sklodowska-Curie Actions COFUND Program. F.M. also acknowledges financial support from the European Union’s Horizon 2020 program, through a FET Open research and innovation action under the grant agreement No. 899141 (PoLLoC). This research was carried out at beamline P21.2 at PETRA III at DESY, a member of the Helmholtz Association (HGF). The authors thank Dr. Malte Blankenburg and Dr. Ulrich Lienert for assistance during the experiment. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. D.B. acknowledges financial support from the Cluster of Excellence “CUI: Advanced Imaging of Matter” of the Deutsche Forschungsgemeinschaft (DFG) - EXC 2056 - project ID 390715994.
Funders | Funder number |
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FET Open research and innovation action | 730872, 899141 |
HORIZON EUROPE Marie Sklodowska-Curie Actions | |
Helmholtz-Gemeinschaft | |
the Deutsche Forschungsgemeinschaft | 390715994 |
Eidgenössische Technische Hochschule Zürich | FEL-15 18-2 |
Horizon 2020 | |
Max Delbrück Center for Molecular Medicine in the Helmholtz Association | |
Exzellenzcluster Ozean der Zukunft |
Keywords
- growth
- in situ
- lead halides
- nanocrystals
- perovskites
- quantum dots
- self-assembly
- X-ray scattering