Optical activation of Si nanowires using Er-doped sol-gel derived silica

Optical activation of Si nanowires (Si-NWs) using sol-gel derived Er-doped silica is investigated. Si-NWs of about 100 mn diameter were grown on Si substrates by the vapor-liquid-solid method using Au catalysts and H₂ diluted SiCl₄. Afterwards, Er-doped silica sol-gel solution was spin-coated, and annealed at 950 °C in flowing N₂/O₂ environment. Such Er-doped silica/Si-NWs nanocomposite is found to combine the advantages of crystalline Si and silica to simultaneously achieve both high carrier-mediated excitation efficiency and high Er³⁺ luminescence efficiency while at the same time providing high areal density of Er ³⁺ and easy current injection, indicating the possibility of developing sol-gel activated Si-NWs as a new material platform for Si-based photonics.