Template-directed vapor–liquid–solid growth of silicon nanowires

Abstract

The synthesis of Si nanowires in nanoporous anodic alumina membranes was demonstrated using a combination of Au electrodeposition and vapor–liquid–solid growth at $\text{500\hspace{0.05em}°}\mathrm{C}$ using ${\mathrm{SiH}}_4$ as the Si source. The average diameter of the nanowires was $\text{200±54\hspace{0.17em}}\mathrm{nm}$ which was close to the pore size distribution of the membranes. High-resolution transmission electron microscopy revealed that the nanowires consist of a crystalline Si core, oriented in the 〈100〉 or 〈211〉 growth direction, with a thin $\text{(<3\hspace{0.17em}}\mathrm{nm})$ native oxide coating. In this process, Au terminates both ends of the growing wires, resulting in the formation of Au–Si–Au nanowires.