Title
In situ study of the formation mechanism of two-dimensional superlattices from PbSe nanocrystals
Author
Geuchies, Jaco J. (European Synchrotron Radiation Facility; Universiteit Utrecht)
Van Overbeek, Carlo (Universiteit Utrecht)
Evers, W.H. (TU Delft ChemE/Opto-electronic Materials; Kavli institute of nanoscience Delft) 
Goris, Bart (Universiteit Antwerpen)
De Backer, Annick (Universiteit Antwerpen)
Gantapara, Anjan P. (Universiteit Utrecht)
Rabouw, Freddy T. (Universiteit Utrecht)
Hilhorst, Jan (European Synchrotron Radiation Facility)
Peters, Joep L. (Universiteit Utrecht)
Konovalov, Oleg (European Synchrotron Radiation Facility)
Petukhov, Andrei V. (Eindhoven University of Technology)
Dijkstra, Marjolein (Universiteit Utrecht)
Siebbeles, L.D.A. (TU Delft ChemE/Opto-electronic Materials)
Van Aert, Sandra (Universiteit Antwerpen)
Bals, Sara (Universiteit Antwerpen)
Vanmaekelbergh, Daniel (Universiteit Utrecht)
Date
2016-12-01
Abstract
Oriented attachment of PbSe nanocubes can result in the formation of two-dimensional (2D) superstructures with long-range nanoscale and atomic order. This questions the applicability of classic models in which the superlattice grows by first forming a nucleus, followed by sequential irreversible attachment of nanocrystals, as one misaligned attachment would disrupt the 2D order beyond repair. Here, we demonstrate the formation mechanism of 2D PbSe superstructures with square geometry by using in situ grazing-incidence X-ray scattering (small angle and wide angle), ex situ electron microscopy, and Monte Carlo simulations. We observed nanocrystal adsorption at the liquid/gas interface, followed by the formation of a hexagonal nanocrystal monolayer. The hexagonal geometry transforms gradually through a pseudo-hexagonal phase into a phase with square order, driven by attractive interactions between the {100} planes perpendicular to the liquid substrate, which maximize facet-to-facet overlap. The nanocrystals then attach atomically via a necking process, resulting in 2D square superlattices.
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DOI
https://doi.org/10.1038/nmat4746
Embargo date
2017-07-01
ISSN
1476-1122
Source
Nature Materials, 15 (12), 1248-1254
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2016 Jaco J. Geuchies, Carlo Van Overbeek, W.H. Evers, Bart Goris, Annick De Backer, Anjan P. Gantapara, Freddy T. Rabouw, Jan Hilhorst, Joep L. Peters, Oleg Konovalov, Andrei V. Petukhov, Marjolein Dijkstra, L.D.A. Siebbeles, Sandra Van Aert, Sara Bals, Daniel Vanmaekelbergh