Gold anchoring on Si sawtooth faceted nanowires

¹ Université Paris-Sud, Institut d'Electronique Fondamentale, UMR 8622 - Orsay, F-91405, France, EU
² CNRS - Orsay, F-91405, France, EU
³ CNRS, Laboratoire de Photonique et de Nanostructures, UPR20, Site Alcatel de Marcoussis Marcoussis, F-91460, France, EU

^a laetitia.vincent@ief.u-psud.fr

Received: 1 February 2011
Accepted: 17 May 2011

Abstract

This paper reports on the sawtooth faceting and the related gold coverage of silicon nanowires (NWs). ⟨ 111⟩-oriented Si NWs were grown on Si(111) substrates by ultra high vacuum chemical vapor deposition using the vapor-liquid-solid mechanism with a gold catalyst. We observed that gold nanoclusters are unequally distributed on the NW surface. They are mainly distributed on only three non-consecutive sidewalls corresponding to the (), () and () planes among the six available crystallographic {112} surfaces. In addition they are anchored on upward {111} facets. This original observation brings enhanced knowledge on the faceting mechanisms. The threefold symmetry of the facet formation and gold anchoring is supported by criteria of minimal Au/Si interfacial energy. Moreover results evidence that the selective presence of gold on the NW sidewalls affects the overall morphology due to an increased radial growth on the covered sidewalls.