Analysis of Chemical Bonding and Structural Network of Gold Silicide in Core–Shell Silicon Nanowire

The Au-catalyzed core–shell silicon nanowires (Si-NWs) were synthesized by chemical vapor deposition by using SiH₄ and H₂ precursor gases. The TEM and FTIR studies revealed that the Si-NWs consist of core silicon surrounded by a thick oxide sheath and Au distributed at the a-SiOx/Si interface. The x-ray photoelectron spectroscopy (XPS) was used to study the chemical composition and electronic environments of gold silicide in the a-SiO_x/Si-NWs. The elemental analysis and chemical network of gold silicide of core–shell Si-NWs were explained on the basis of the random atomic distribution of Si, O and Au atoms. The Raman spectra and XRD peak reveal the crystalline core of Si-NWs. The individual contribution to the Au (4d) core orbital was deconvoluted to Au-Si-Au, Au-Si-O, Au-Au, Au-O-Au, Au-O-Si and Au=O/Au-O₂ bonding structure. The analysis shows that the O linked with Si and Au has also contributed to growth of Si-NWs.