Arrays of vertically aligned and hexagonally arranged ZnO nanowires: a new template-directed approach

A new template-directed method for large-scale fabrication of hexagonally patterned and vertically aligned ZnO nanowires is demonstrated. The process involves a novel type of metal membrane, gold catalyst templates produced using the membrane as the deposition mask, and catalyst-guided vapour-phase growth of ZnO nanowires. The metal membranes, composed of hexagonal nanotube arrays, are electrochemically replicated from ordered porous alumina. The obtained ZnO nanowires are uniformly aligned perpendicular to the GaN surface and have a distribution according to the pattern defined by the nanotube membrane. We also demonstrate that by modifying the electrochemical parameters and growth conditions, the diameter of the nanowires can be varied in the range 30-110 nm.