Electron tunneling between two electrodes mediated by a molecular wire containing a redox center

TL;DR

This paper derives a quantum conductivity expression for a molecular wire with a redox center in an electrochemical environment, revealing complex current behaviors and spectroscopic possibilities.

Contribution

It provides an explicit formula for conductivity considering solvent interactions and demonstrates novel electronic features in a three-atom chain model.

Findings

Current-voltage curves exhibit rectification and negative differential resistance.

Electronic spectroscopy of intermediate states is feasible at constant bias.

Strong redox-electronic level interactions lead to unique transport phenomena.

Abstract

We derive an explicit expression for the quantum conductivity of a molecular wire containing a redox center, which is embedded in an electrochemical environment. The redox center interacts with the solvent, and the average over the solvent configurations is performed numerically. Explicit calculations have been performed for a chain of three atoms. When the redox center interacts strongly with neighboring electronic levels, the current-potential curves show interesting features like rectification, current plateaus and negative differential resistance. Electronic spectroscopy of intermediate states can be performed at constant small bias by varying the electrochemical potential of the wire.