Determination of carrier density of ZnO nanowires by electrochemical techniques

The carrier density of ZnO nanowires has been determined by means of electrochemical impedance spectroscopy. A model taking into account the geometry of ZnO nanowires has been developed and the differences with the standard flat model, as curved Mott-Schottky plots, are discussed. The as-grown electrodeposited samples present a high donor density of $6.2\times {10}^{19}{\mathrm{cm}}^{-3}$ , dramatically reduced by two orders of magnitude after an annealing in air at $450°\mathrm{C}$ during $1\mathrm{h}$ . The results show that the surface of the ZnO nanowires is active; therefore this system appears as a useful structure to support a functionalized nanostructured devices.