Controlling nanocrystal superlattice symmetry and shape-anisotropic interactions through variable ligand surface coverage |
| |
Authors: | Choi Joshua J Bealing Clive R Bian Kaifu Hughes Kevin J Zhang Wenyu Smilgies Detlef-M Hennig Richard G Engstrom James R Hanrath Tobias |
| |
Institution: | School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA. |
| |
Abstract: | The assembly of colloidal nanocrystals (NCs) into superstructures with long-range translational and orientational order is sensitive to the molecular interactions between ligands bound to the NC surface. We illustrate how ligand coverage on colloidal PbS NCs can be exploited as a tunable parameter to direct the self-assembly of superlattices with predefined symmetry. We show that PbS NCs with dense ligand coverage assemble into face-centered cubic (fcc) superlattices whereas NCs with sparse ligand coverage assemble into body-centered cubic (bcc) superlattices which also exhibit orientational ordering of NCs in their lattice sites. Surface chemistry characterization combined with density functional theory calculations suggest that the loss of ligands occurs preferentially on {100} than on reconstructed {111} NC facets. The resulting anisotropic ligand distribution amplifies the role of NC shape in the assembly and leads to the formation of superlattices with translational and orientational order. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |