title: Soft epitaxy of nanocrystal superlattices.
abstract: Epitaxial heterostructures with precise registry between crystal layers play a key role in electronics and optoelectronics. In a close analogy, performance of nanocrystal (NC) based devices depends on the perfection of interfaces formed between NC layers. Here we systematically study the epitaxial growth of NC layers for the first time to enable the fabrication of coherent NC layers. NC epitaxy reveals an exceptional strain tolerance. It follows a universal island size scaling behaviour and shows a strain-driven transition from layer-by-layer to Stranski-Krastanov growth with non-trivial island height statistics. Kinetic bottlenecks play an important role in NC epitaxy, especially in the transition from sub-monolayer to multilayer coverage and the epitaxy of NCs with anisotropic shape. These findings provide a foundation for the rational design of epitaxial structures in a fundamentally and practically important size regime between atomic and microscopic systems.
authors.affiliation: 1] Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA [2] James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Sara M
authors.initials: SM
authors.lastname: Rupich
authors.affiliation: Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Castro
authors.affiliation: 1] James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA [2] Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: William T M
authors.initials: WT
authors.lastname: Irvine
authors.affiliation: 1] Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA [2] James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA [3] Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Talapin