Resistance switching of an individual Ag2S/Ag nanowire heterostructure

Ag/Cu-based chalcogenide ionic conductors are candidates for use in applications in resistance-switching and nonvolatile memory devices. We report the investigation of the electrical properties of individual Ag2S/Ag heteronanowires (HNWs) by atomic force microscopy (AFM) using a nanoscale-tip electrode. Hysteretic current–voltage (IV) curves and the polarity-dependent resistance-switching phenomenon in an individual Ag2S/Ag HNW were observed. A local impedance spectroscopy measurement of Ag2S/Ag HNWs was performed to reveal the interface-related electrical characteristics. The DC-bias-dependent impedance spectra suggested the occurrence of charge and mass transfer at the interface of the electrode/mixed conductor. It is proposed that reversible resistance switching originates from the creation and rupture of filament-like conducting pathways inside the Ag2S/Ag HNW.