Combinatorial growth of Si nanoribbons

Tae-Eon Park,Ilsoo Kim,Joonyeon Chang,Peter Voorhees,Heon-Jin Choi,Ki-Young Lee

doi:10.1186/1556-276x-6-476

Abstract

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.

Highlights

One-dimensional nanostructures have attracted much attention in the research community owing to their novel physical and chemical properties and due to their easy manipulation as building blocks for nanoscale devices
Si NRs were synthesized on Si substrates assisted by Pt as a catalyst via chemical vapor transport system [9,10]
To address the growth mechanism, the evolution of Si NRs over time was examined by transmission electron microscopy (TEM)

Summary

Introduction

One-dimensional nanostructures have attracted much attention in the research community owing to their novel physical and chemical properties and due to their easy manipulation as building blocks for nanoscale devices. To prepare the samples for cross-section TEM observation, the saw-like edged NRs were dispersed via ethanol solution onto Ge substrates coated with 30 nm of Au film.

Results

Conclusion