Low-dimensional semiconductor superlattices formed by geometric control over nanocrystal attachment.
Oriented attachment, the process in which nanometer-sized crystals fuse by atomic bonding of specific crystal facets, is expected to be more difficult to control than nanocrystal self-assembly that is driven by entropic factors or weak van der Waals attractions. Here, we present a study of oriented attachment of PbSe nanocrystals that counteract this tuition. The reaction was studied in a thin film of the suspension casted on an immiscible liquid at a given temperature. We report that attachment can be controlled such that it occurs with one type of facets exclusively. By control of the temperature and particle concentration we obtain one- or two-dimensional PbSe single crystals, the latter with a honeycomb or square superimposed periodicity in the nanometer range. We demonstrate the ability to convert these PbSe superstructures into other semiconductor compounds with the preservation of crystallinity and geometry.
Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, P.O. Box 80.000, 3508 TA, Utrecht, The Netherlands.
Wiel H
WH
Evers
Bart
B
Goris
Sara
S
Bals
Marianna
M
Casavola
Joost
J
de Graaf
René
R
van Roij
Marjolein
M
Dijkstra
Daniël
D
Vanmaekelbergh