Next, CVCs were obtained for these device architectures, and the onset potentials and slopes (conductance) of the ohmic, limiting and overlimiting regimes were compared. The same procedure for device preparation as described in the preceding paragraph was employed, and then, a voltage sweep (0.25 V steps every 0.33 s) was applied and the current monitored. In the planar Au device, three distinct regimes are observed in the CVC (blue line, Figure ). In the Ag/Au device (red line, Figure ), there is a direct transition from the ohmic to overlimiting regime.