One-step fabrication of uniform Si-core/CdSe-sheath nanocables.

A simple one-step thermal evaporation of CdSe powder using Si substrate at controlled conditions results in ultrauniform Si-core/CdSe-sheath nanocables. These nanocables are approximately 80 nm in diameter and several tens of micrometers in length. Detailed microstructure and chemical composition analysis of the nanocables indicates that they are composed of a single crystalline Si (cubic) core and CdSe (hexagonal) sheath. The experimental evidence suggested that the Si nanowires can be directly grown from the Si substrate via an oxide-assisted growth mechanism and further served as templates for CdSe, resulting in nanocable heterostructures.