Silicon nanoribbons (Si NRs) with a thickness of about 30 nm and a width up to a few micrometers were synthesized. Systematic observations indicate that Si NRs evolve via the following sequences: the growth of basal nanowires assisted with a Pt catalyst by a vapor-liquid-solid (VLS) mechanism, followed by the formation of sawlike edges on the basal nanowires and the planar filling of those edges by a vapor-solid (VS) mechanism. Si NRs have twins along the longitudinal < 110 > growth of the basal nanowires that also extend in < 112 > direction to edge of NRs. These twins appear to drive the lateral growth by a reentrant twin mechanism. These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction. These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twinassisted VS mechanism for lateral growth.
Bibliographical noteFunding Information:
This research was supported by the Second Stage of Brain Korea 21 project in Division of Humantronics Information Materials, a grant from the National Research Laboratory program (R0A-2007-000-20075-0), Nano R&D program (2009-0082724), and Pioneer research program for Converging technology (2009-008-1529) through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics