Orientationally ordered silicon nanocrystal cuboctahedra in superlattices

This is an open access article published under an ACS AuthorChoice License.-- et al.Uniform silicon nanocrystals were synthesized with cuboctahedral shape and passivated with 1-dodecene capping ligands. Transmission electron microscopy, electron diffraction, and grazing incidence wide-angle and small-angle X-ray scattering show that these soft cuboctahedra assemble into face-centered cubic superlattices with orientational order. The preferred nanocrystal orientation was found to depend on the orientation of the superlattices on the substrate, indicating that the interactions with the substrate and assembly kinetics can influence the orientation of faceted nanocrystals in superlattices.This research was funded by the Robert A. Welch Foundation (Grant F-1464 and F-1696) and the National Science Foundation (Grant CBET-1403768). CHESS is supported by the NSF & NIH/NIGMS via NSF award DMR-1332208. J.A. and M.d.l.M. acknowledge funding from Generalitat de Catalunya 2014 SGR 1638 and MINECO projects MAT2014-59961-C2-2-R and Severo Ochoa Program (Grant SEV-2013-0295).Peer Reviewe