Facet-Dependent Electrical Conductivity Properties of Silver Oxide Crystals.

Ag2 O cubes, truncated octahedra, rhombic dodecahedra, and rhombicuboctahedra were synthesized in aqueous solution. Two tungsten probes were brought into contact with a single particle for electrical conductivity measurements. Strongly facet-dependent electrical conductivity behaviors have been observed. The {111} faces are most conductive. The {100} faces are moderately conductive. The {110} faces are nearly non-conductive. When electrodes contacted two different facets of a rhombicuboctahedron, asymmetrical I-V curves were obtained. The {111} and {110} combination gives the best I-V curve expected for a p-n junction with current flowing in one direction through the crystal but not in the opposite direction. Density of states (DOS) plots for varying number of different lattice planes of Ag2 O match with the experimental results, suggesting that the {111} faces are most electrically conductive. The thicknesses of the thin surface layer responsible for the facet-dependent properties of Ag2 O crystals have been determined.