Preparation of silicon nanowires by hydrothermal deposition on silicon substrates.

Smooth silicon nanowires (SiNWs) without metallic catalysts have been prepared using silicon monoxide as starting material by hydrothermal deposition on silicon substrates. Scanning electron microscopy and transmission electron microscopy demonstrate that SiNWs have smooth surfaces and around 170 nm in diameter as well as larger than 10 μm in length. High-resolution transmission electron microscopy shows that each nanowire consists a polycrystalline silicon core and an amorphous silica sheath. Si and silicon oxide, is proposed, are generated from silicon monoxide under high temperature and high pressure of hydrothermal conditions. The growth mechanism of silicon nanowires is proposed as the oxide-assisted growth mechanism. [ABSTRACT FROM AUTHOR]