Effect of the Debye screening on the tunnel current through simple electrochemical bridged contact

General equations for tunnel current through electrochemical contact containing a redox-center in molecular bridge group are observed with allowing for potential distribution in the tunnel gap. Simple approximate expressions appropriate for the analysis of experimental data are also derived. The dependences of the position of the current maximum and its width on the bias voltage, the position of the bridge group in the tunnel gap, and the system's physical parameters (like the electrolyte ionic strength) are calculated.

It is shown that the Debye screening in solution affects these dependences significantly.