Structural and Optical Properties of Si-Core/SiO x -Shell Nanowires

Si-core/SiO (x) -shell nanowires (NWs) have been synthesized on Si(111) surfaces using the vapor-liquid-solid technique. A 2-nm-thick Au layer was deposited by electron-beam evaporation as a metal catalyst. Au nanoparticles were formed by annealing at high temperature, resulting in subsequent formation of NWs. The Si-core/SiO (x) -shell structure of the NWs was investigated via scanning electron microscopy, transmission electron microscopy, x-ray diffraction analysis, and Raman spectroscopy. Photoluminescence measurements demonstrated a quantum confinement effect because of the reduced diameter of the NWs.