Controlled growth of vertical ZnO nanowires on copper substrate

We present an approach for diameter control of vertically aligned ZnO nanowires (NWs) grown directly on copper substrates. Vapor-solid growth was done at 550 degrees C with solid Zn precursor under Ar/O-2 flow, and the resulting nanowires with in situ-controllable diameters ranged between 50 to 500 nm. The nanowires were observed to elongate in tip growth and diameters were directly controlled by varying the oxygen concentration. Direct growth of vertical wires on metal substrates is expected to be useful to construct piezoelectric devices and applications involving sensors and detectors. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4793758]