Synthesis of Tin nitride Sn xN y nanowires by chemical vapour deposition
SourceNanoscale Research Letters
Google Scholar check
MetadataShow full item record
Tin nitride (Sn xN y) nanowires have been grown for the first time by chemical vapour deposition on n-type Si(111) and in particular by nitridation of Sn containing NH 4Cl at 450 °C under a steady flow of NH 3. The Sn xN y nanowires have an average diameter of 200 nm and lengths ≥5 μm and were grown on Si(111) coated with a few nm's of Au. Nitridation of Sn alone, under a flow of NH 3 is not effective and leads to the deposition of Sn droplets on the Au/Si(111) surface which impedes one-dimensional growth over a wide temperature range i.e. 300-800 °C. This was overcome by the addition of ammonium chloride (NH 4Cl) which undergoes sublimation at 338 °C thereby releasing NH 3 and HCl which act as dispersants thereby enhancing the vapour pressure of Sn and the one-dimensional growth of Sn xN y nanowires. In addition to the action of dispersion, Sn reacts with HCl giving SnCl 2 which in turn reacts with NH 3 leading to the formation of Sn xN y NWs. A first estimate of the band-gap of the Sn xN y nanowires grown on Si(111) was obtained from optical reflection measurements and found to be ≈2.6 eV. Finally, intricate assemblies of nanowires were also obtained at lower growth temperatures. © to the authors 2009.