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Shape‐selective synthesis of II–VI semiconductor nanowires
Author(s) -
Fasoli A.,
Colli A.,
Hofmann S.,
Ducati C.,
Robertson J.,
Ferrari A. C.
Publication year - 2006
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200669142
Subject(s) - nanorod , nucleation , nanocrystal , nanowire , materials science , nanotechnology , epitaxy , semiconductor , substrate (aquarium) , fabrication , chemical vapor deposition , chemical engineering , optoelectronics , chemistry , layer (electronics) , medicine , oceanography , alternative medicine , organic chemistry , pathology , geology , engineering
Polar II–VI semiconductors can nucleate in complex shapes ranging from nanowires to nanoribbons, nanosaws and multipods. Here we demonstrate the deterministic and fully reproducible shape‐selective growth of several morphologies of CdSe and ZnTe nanocrystals by a steady‐state vapour transport process. A simple pressure‐based precursor‐flow shutter excludes any effects of temperature ramping, ensuring reproducible shape selectivity for each set of deposition parameters. Once thermal gradients are eliminated, we show that the transition from one nanocrystal shape to another is controlled just by the interplay of precursor impinging on the substrate (ruled by the powder temperature T P ) and sample surface kinetics (ruled by the sample temperature T S ). Furthermore, a regime is found where seeded, epitaxial growth of CdSe nanorods becomes dominant over the conventional catalyst‐assisted nucleation. This allows the fabrication of vertical nanorod arrays free of any metal contamination. Seeded growth of branched and tetrapod‐like nanocrystals is also possible by further optimisation of the growth parameters. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)