Morphologies and electrical properties of multiple CuO nanowire-based device controlled by electroplating and thermal oxidation process

Metal oxide nanowire-based devices have been widely studied for chemical sensors. Based on the knowledge of the work functions of copper oxide nanowires and metal electrodes, the electrical junction properties such as Schottky barrier height could be modulated by changing the electrode material or decorating the nanowires with another material. Especially for the nanowire decoration process, nanoparticle sputtering or wet chemical synthesis has been used as a post processing method, which is complex and costly. These drawbacks have greatly limited the actual applications of the nanowire-based devices. In this work, a facile one-step thermal oxidation of electroplated interdigitated Cu patterns is proposed for multiple copper oxide nanowire-based device fabrication and a modulation mechanism based on adjusting nanowire density and total area of CuO/Cu–Au interface is discussed. The initial thickness of Cu and the electrode configuration play a deterministic role in the final CuO nanowire morphologies and their junction properties, which is a new finding.