Template synthesis of M/M₂S (M = Ag, Cu) hetero-nanowires by electrochemical technique

Metal chalcogenide-based mixed ionic-electronic conductors such as Ag₂S and Cu₂S can be specifically architected for application in nanoelectronic devices. We present a template-confined synthesis of metal chalcogenide (e.g., Ag₂S, Cu₂S) nanowires for mixed conductor-based nanoelectronics. First, the metal nanowire array was electroplated into pores of a porous alumina membrane. Anodic polarization was then used to transform the metal into the metal sulfide in aqueous hydrosulfide (HS^-) solutions. The as-synthesized mixed conductors' hetero-nanowire array was characterized by X-ray diffraction and electron microscopy. Electronic transport measurements show non-linear and reproducible electrical switching characteristics. The high and low resistance states can be reversibly changed by altering the polarity of the applied voltage between the bottom and top electrodes. The electrical-switching behavior is attributed to electric-field-induced accumulation and dissolution of metallic conducting pathways inside the mixed conductors' nanowires.