Low-Dimensional Semiconductor Superlattices Formed by Geometric Control over Nanocrystal Attachment

• Published in: Nano letters 2013-06, Vol.13 (6), p.2317-2323
• Main Authors: Evers, Wiel H, Goris, Bart, Bals, Sara, Casavola, Marianna, de Graaf, Joost, van Roij, René, Dijkstra, Marjolein, Vanmaekelbergh, Daniël
• Format: Article
• Language: English
• Subjects: Attachment; Cross-disciplinary physics: materials science; rheology; Crystal structure; Exact sciences and technology; Fuses; Honeycomb; Materials science; Methods of nanofabrication; Nanocrystalline materials; Nanocrystals; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Physics; Self assembly; Semiconductors
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl303322k

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.