Growth and characterization of FeSi nanowires by chemical vapor deposition for gas sensing applications

Abstract

FeSi nanowires were synthesized via a chemical vapor deposition method. Anhydrous FeCl3 powder in this case served as the Fe source and was evaporated at a temperature of 1100oC to interact with silicon substrates which served as the silicon source. The nanowires followed the vapor solid (VS) growth mechanism, which does not require the use of a metal catalyst; the native silicon oxide layer on the silicon substrates played the role of the catalyst in the growth of these nanostructures. A second growth mechanism, involving the use of a metal catalyst to assist in the growth of the nanowires was attempted by depositing a thin film of gold on silicon substrates. The reaction yielded SiOx nanowires; these results are discussed in detail in Chapter 5. All the nanostructures were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Photoluminescence Spectroscopy (PL), Raman Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR).