Metal-catalyzed semiconductor nanowires: a review on the control of growth directions

Semiconductor nanowires have become an important building block for nanotechnology. The growth of semiconductor nanowires using a metal catalyst via the vapor–liquid–solid (VLS) or vapor–solid–solid (VSS) mechanism has yielded growth directions in ⟨1 1 1⟩, ⟨1 0 0⟩ and ⟨1 1 0⟩ etc. In this paper, we summarize and discuss a broad range of factors that affect the growth direction of VLS or VSS grown epitaxial semiconductor nanowires, providing an indexed glimpse of the control of nanowire growth directions and thus the mechanical, electrical and optical properties associated with the crystal orientation. The prospect of using planar nanowires for large area planar processing toward future nanowire array-based nanoelectronics and photonic applications is discussed.