Abstract
Oriented attachment of synthetic semiconductor nanocrystals is emerging as a route for obtaining new semiconductors that can have Dirac-type electronic bands such as graphene, but also strong spin-orbit coupling. The two-dimensional (2D) assembly geometry will require both atomic coherence and long-range periodicity of the superlattices. We show how the interfacial self-assembly and oriented attachment of nanocrystals results in 2D metal chalcogenide semiconductors with a honeycomb superlattice. We present an extensive atomic and nanoscale characterization of these systems using direct imaging and wave scattering methods. The honeycomb superlattices are atomically coherent and have an octahedral symmetry that is buckled; the nanocrystals occupy two parallel planes. Considerable necking and large-scale atomic motion occurred during the attachment process.
Original language | English |
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Pages (from-to) | 1377-1380 |
Number of pages | 4 |
Journal | Science |
Volume | 344 |
Issue number | 6190 |
DOIs | |
Publication status | Published - 20 Jun 2014 |
Funding
We thank ESRF (Grenoble, France) for providing the synchrotron beamtime and the staff of ESRF beamline ID-01 for their support. We thank C. van Overbeek for his help on the PbS sample. This research is part of the programs "Control over Functional Nanoparticle Solids (FNS)" and "Designing Dirac Carriers in semiconductor honeycomb superlattices (DDC)," which are supported by the Foundation of Fundamental Research on Matter (FOM), which is part of the Dutch Research Council (NWO). The authors also acknowledge financial support from the European Research Council (ERC Advanced Grant 24691-COUNTATOMS and ERC Starting Grant #335078-COLOURATOM). The authors also appreciate financial support from the European Union under the Seventh Framework Program [Integrated Infrastructure Initiative 262348 European Soft Matter Infrastructure (ESMI)]. This work was supported by the Flemish Fund for Scientific Research (FWO Vlaanderen) through a Ph.D. research grant to B.G.
Keywords
- ORIENTED ATTACHMENT
- ELECTRON TOMOGRAPHY
- CATION-EXCHANGE
- DIRAC FERMIONS
- GRAPHENE
- NANOPARTICLES
- MICROSCOPY
- NANORODS
- GROWTH