Imaging and analysis of axial heterostructured silicon nanowires

Abstract

Silicon nanowires with axially varying n - and p -doping were grown by the vapor-liquid-solid approach using gold as the catalyst. The microstructures of the axial heterostructured silicon nanowires were studied using electron microscopy techniques. The nanowire sidewalls exhibit periodic nanofaceting, which is dopant-dependent. The nanofaceting occurs during the enhanced sidewall growth that arises when the diborane dopant gas is introduced. It is also found that the silicon nanowire can crystallize in a hexagonal phase, which is thermodynamically unstable in bulk silicon at ambient and may be due to the large surface stress present during the nucleation of SiNWs.