Charge transport through a flexible molecular junction

TL;DR

This paper investigates vibrational effects on electron transport in a flexible biphenyl molecular junction using exact scattering methods, analyzing current-voltage behavior and tunneling processes across various conditions.

Contribution

It introduces a mechanistic model combined with numerically exact scattering techniques to study vibrationally inelastic electron transport in flexible molecular junctions.

Findings

Vibrational excitation significantly influences transmission probabilities.

Electron-assisted tunneling in torsional potentials is characterized.

Approximate methods' validity for transmission calculations is evaluated.

Abstract

Vibrationally inelastic electron transport through a flexible molecular junction is investigated. The study is based on a mechanistic model for a biphenyl molecule between two metal electrodes. Employing methods from electron-molecule scattering theory, which allow a numerically exact treatment, we study the effect of vibrational excitation on the transmission probability for different parameter regimes. The current-voltage characteristic is analyzed for different temperatures, based on a Landauer-type formula. Furthermore, the process of electron assisted tunneling between adjacent wells in the torsional potential of the molecule is discussed and the validity of approximate methods to describe the transmission probability is investigated.