Abstract: Nanoelectronics is an important area of research in nanotechnology and nanoscience, in which nano structures with electronics functionality are designed and fabricated. In this paper, a Au/Ag/Ag₂S/Au solid-state electrochemical nanoswitch was constructed by using electrochemical methods from the “bottom-up” approach. The Ag₂S nanoelectrochemical switch fabricating procedure includes three steps: (1) A silver layer was electrodeposited on one of a pair of facing Au electrodes which was separated with about 2 μm gap width; (2) the surface of the silver layer was then converted to Ag₂S by electrochemical oxidation in a basic Na₂S solution; (3) the gap was narrowed down to about 1 nm by electrodepositing Au atoms on to the other one of the facing pair electrodes. It is demonstrated that such a device can switch between “on” and “off” states at room temperature and in air. A gap of 1 nm is the key structure of the switch. The Ag₂S switch works by controlling the formation and annihilation of an atomic Ag-bridge at the tip point between two electrodes. The reversibility and stability of the switch is satisfactory with a current difference between “on” and “off” states more than three orders of magnitude.

Key words: Ag₂S, Nanoswitch, Electrochemistry, Electrodeposition