Interaction effects in electric transport through self-assembled molecular monolayers

TL;DR

This paper presents a theoretical study of how inter-molecular Coulomb interactions influence electric transport in molecular monolayers, revealing correlated currents, non-linear I-V features, and charge trap effects causing negative differential resistance.

Contribution

It introduces a modified master equation approach to model transport in large interacting molecular systems, highlighting the impact of Coulomb interactions and charge traps.

Findings

Inter-molecular Coulomb interactions cause correlated currents.

Non-linear current-voltage characteristics are observed.

Charge traps can induce negative differential resistance.

Abstract

We theoretically investigate the effect of inter-molecular Coulomb interactions on transport through molecular monolayers (or other devices based on a large number of nanoscale conductors connected in parallel). Due to the interactions, the current through different molecules become correlated, resulting in distinct features in the non-linear current-voltage characteristics, as we show by deriving and solving a type of modified master equation, suitable for describing transport through an infinite number of interacting conductors. Furthermore, if some of the molecules fail to bond to both electrodes, charge traps can be induced at high voltages and block transport through neighboring molecules, resulting in negative differential resistance.