Cu2O nanowires in an alumina template:: Electrochemical conditions for the synthesis and photoluminescence characteristics

Cu2O nanowires, mainly consisting of (100) and (200) polycrystalline structure with a length of 4 mu m are prepared by electro-chemical deposition using a porous alumina template. It is found that the optimized electrochemical conditions to prepare Cu2O nanowires are different from those for the formation of a bulk thin Cu2O layer since different pH values are found between the tip of the pores and the bulk, due to diffusion limits in porous alumina with an extremely high aspect ratio of 300. We point out that Cu2O (200), Cu2O (111), Cu, and co-deposited alloys can be obtained under specific electrochemical conditions. In addition, the optical band gap of the prepared Cu2O nanowires with a length of 4 mu m and a diameter of 200 nm is estimated to be 2.17 eV from photoluminescence measurements.