Combinatorial growth of Si nanoribbons
1 Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, South Korea
2 Spin Device Research Center, Korea Institute of Science and Technology, Seoul 136-791, South Korea
3 Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
Nanoscale Research Letters 2011, 6:476 doi:10.1186/1556-276X-6-476Published: 27 July 2011
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 saw-like 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 twin-assisted VS mechanism for lateral growth.