A Simple Technique to Grow Long Vertically Aligned CuO Nanowires on Oxidized Silicon Substrate

This paper describes the growth of CuO nanowires on oxidized Si wafer by an oxidation reaction. Copper thin films of about 3 μm thickness were sputter deposited on oxidized Si wafer. The samples were then annealed in a furnace at 500 °C, 600 °C and 700 °C under normal atmospheric conditions. After heating, the color of the deposited copper turned black. Electron microscopic studies indicated that the black film consisted of CuO nanowires having diameter in the range of 50–200 nm and length up to 30 μm. The diameter and length could be varied by varying the annealing temperature. The nanowires of CuO were grown on large area (2 inch diameter oxidized silicon wafer) thus making it feasible to use these for device fabrication such as gas sensors. The X-ray diffractogram (XRD) and Energy Dispersive X-ray (EDX) studies were carried out to investigate the crystal structure and growth mechanism of nanowires. The possible mechanism is also proposed to explain the growth of these CuO nanowires.