First Principles Study of Electron Tunneling Through Ice
J. Phys. Chem. C, October (2012)
Understanding the electronic transport properties of nanoconfined systems under wetting conditions is essential for many applications ranging from molecular nano-junctions to nanoelectronics. The fundamental mechanism of the EC-STM operation in aqueous solution however is still not completely understood.
With the aim of understanding electrochemical scanning tunnel microscopy experiment in aqueous environment we investigate electron transport through ice in the coherent limit. By comparing the decay coefficient for different ice structures and different Au electrode orientations we find that the electron transport occurs via tunneling with almost one-dimensional character. We demonstrate that the slow decay of the current with the ice thickness is largely due to the small effective mass of the conduction electrons and that a finite bias measurement may be capable of sorting polar from non polar interfaces due to the asymmetry of the current-voltage curves for polar interfaces.