New nanowire heterostructures: SnO2 nanowires epitaxial growth on Si bicrystalline nanowires

Combining thermal decomposition and evaporation of a mixed powder of SiO and SnO2 under careful temperature control resulted in SnO2 nanowires epitaxial growth on Si bicrystalline nanowires, forming new three layered radial Si-Si-SnO2 nanowire heterostructures, which the nature of interfacial regions and phase boundaries are different from the characteristics of axial composite nanowires. Each Si-Si-SnO2 composite nanowire has a uniform diameter along its whole length; the typical diameter of the nanowires ranges from 50 to 150 nm, and the diameters of Si bicrystalline nanowires and SnO2 nanowires within a nanowire heterostructure are similar to 30-100 nm. These Si-Si-SnO2 nanowire heterostructures display unique intensive green luminescence emission compared to that of UV emissions of the near-band edge of SnO2.