Metal-catalyst-free epitaxial growth of aligned ZnO nanowires on silicon wafers at low temperature

Hexagonally well-faceted ZnO nanowire arrays were successfully aligned to Si wafers using a metal-catalyst-free physical vapour deposition method at 500°C. The ZnO nanowires prepared using the metal-catalyst-free approach are single-crystalline and of high-purity. The one-dimensional growth of these nanowires with an average diameter of 100 nm follows the c axis direction of wurtzite ZnO. The as-synthesized nanowire arrays on Si wafers could offer novel opportunities for both fundamental research and technological applications.