Structural and optical properties of Au-catalyzed SiNWs grown using pulsed plasma-enhanced chemical vapour deposition

Silicon nanowires (SiNWs) were grown on indium tin oxide-coated glass substrates using pulsed plasma-enhanced chemical vapour deposition (PPECVD) with gold (Au) as a catalyst. Various thicknesses of Au thin films ranging from 10 nm to 100 nm were deposited on the substrates by thermal evaporation. The surface morphological study of the prepared wires showed that the wire diameter increased as the catalyst film thickness increased. The X-ray diffraction patterns of the prepared SiNWs illustrated that the grown wires had cubic phase, and the crystallinity was enhanced as the catalyst thickness increased. The photoluminescence spectra of the SiNWs had a red emission band whose band location and shape were found to be dependent on catalyst thickness. The Raman spectra of the prepared nanowires showed that the first order transverse band shifted toward lower frequencies compared with the c-Si band location. The first order transverse band approached the c-Si band location as the wire diameter increased due to the increasing catalyst film thickness. (C) 2013 Elsevier Ltd. All rights reserved.