Millimeter-long and uniform silicon nanocables

An ultralong Si nanocable has been prepared by simple thermal evaporation of SiO powder mixed with a small amount of Sn. The nanocable has a uniform diameter of about 680 nm and millimeters in length. The core of the nanocable is single-crystal Si with an average diameter of 160 nm, and the shell is composed of compact amorphous SiO _x with a uniform thickness of 260 nm. The cladding SiO _x emits strong light in a wide spectral range from UV to visible. In particular, each nanocable has a droplet head of Si-Sn eutectic and an uncovered Si core at the tail. The nanocables can be directly fabricated into metal-oxide-semiconductor field effect transistors (MOSFETs) via simple thermal deposition of Au electrodes. The performance of the MOSFETs reveals that the Si nanocables are p-type semiconductors with 1.1 × 10 ¹⁷ cm ^-3 hole concentration and 3.69 cm ² V ^-1 s ^-1 hole mobility. © 2008 American Chemical Society.