Copper indium diselenide nanowire arrays by electrodeposition in porous alumina templates

A simple template assisted approach for fabricating I–III–VI semiconductor nanowire arrays is presented. Vertically aligned arrays of CuInSe 2 (CIS) nanowires of controllable diameter and length were synthesized by pulse cathodic electrodeposition from a novel acidic electrolyte solution into anodized alumina (AAO) templates, followed by annealing at 220 °C in vacuum. Scanning electron microscopy revealed that the nanowires were dense and compact. Depending on the dimensions of the starting AAO template, the diameters ranged from 5 to 40 nm and the lengths ranged from 600 nm to 5 µm; the grain size was estimated to be less than 5 nm. The composition of the nanowires was analyzed by energy dispersive x-ray (EDX) spectroscopy, and was found to be close to stoichiometric CuInSe 2 within the limit of the resolution of the EDX technique. High resolution transmission electron microscopy and x-ray diffraction revealed high purity CuInSe 2 nanowires with a preferred [112] orientation.