Nanostructures and self-catalyzed growth of SnO2

SnO 2 nanostructures including one-dimensional nanowires and two-dimensional nanobelts have been grown on a gold covered single crystal silicon substrates using thermal evaporation of active carbon and SnO2 powders. Field emission scanning electron microscopy, x-ray diffraction, Raman spectra, and high-resolution transmission electron microscopy are used to identify the morphology and the structure of these resulting SnO2 nanostructures. Based on these experimental analyses, we found self-catalyzed growth of SnO2 nanocrystals on top of SnO2 nanowires, i.e., SnO2 can spontaneously nucleate on the (110) crystalline plane of SnO2 nanowires without any catalyst. The growth behavior of these synthesized SnO2 nanostructures is discussed on the basis of the vapor-liquid-solid mechanism.