Characterizations of Ohmic and Schottky-behaving contacts of a single ZnO nanowire

International audience; Current–voltage and Kelvin probe force microscopy (KPFM) measurements were performedon single ZnO nanowires. Measurements are shown to be strongly correlated with the contactbehavior, either Ohmic or diode-like. The ZnO nanowires were obtained by metallo-organicchemical vapor deposition (MOCVD) and contacted using electronic-beam lithography.Depending on the contact geometry, good quality Ohmic contacts (linear I–V behavior) ornon-linear (diode-like) contacts were obtained. Current–voltage and KPFM measurements onboth types of contacted ZnO nanowires were performed in order to investigate their behavior.A clear correlation could be established between the I–V curve, the electrical potential profilealong the device and the nanowire geometry. Some arguments supporting this behavior aregiven based on technological issues and on depletion region extension. This work will help tobetter understand the electrical behavior of Ohmic contacts on single ZnO nanowires, forfuture applications in nanoscale field-effect transistors and nano-photodetectors.