Excess-silver-induced bridge formation in a silver sulfide atomic switch

Structural properties and electron transport of a Ag2S atomic switch composed of Ag-Ag2S-Ag heterostructure are investigated by nonequilibrium Green's function calculations considering the effect of excess Ag in the Ag2S layer. In addition to confirming experimentally the formation of the Ag bridge inside Ag2S, the bridge is found to consist of units having a structure similar to that of the Ag (111) face in the bulk Ag. The analyses of Mulliken population, transmission spectra, and current-voltage characteristics reveal that the bridge has a conductive and metallic nature. (c) 2008 American Institute of Physics.