High-performance GaN/Cu2O nanowires heterojunction synthesized by physical vapor deposition

The heterojunction between n-GaN nanowires (NWs) and p-cuprous oxide (Cu2O) (111) is fabricated vertically by thermal evaporation of GaN conventional powders without using any catalyst or template. The high-quality NW/Cu2O heterostructure is confirmed by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, selected area electronic diffraction, and energy-dispersive spectroscopy measurements. Diameters of these NWs range from 200 to 400 nm and their lengths arrive at several micrometers. In addition, the room-temperature photoluminescence properties of prepared products have been investigated. The results show that a strong sharp excitonic emission reveals excellent optical property superior to state-of-the-art GaN NWs on silicon or diamond substrates underlining a promising efficient ultraviolet (UV) optoelectronic device based on GaN/Cu2O heterojunction. (c) 2012 Elsevier B.V. All rights reserved.