Intermolecular Effect in Molecular Electronics

TL;DR

This paper explores how lateral intermolecular interactions influence conductance in molecular electronics, revealing that substrate-mediated interactions significantly enhance conductance and produce notable resonances.

Contribution

It introduces a combined Green function and DFT approach to analyze substrate-mediated intermolecular effects in molecular conductance.

Findings

Conductance increases due to intermolecular interactions.

Substrate-mediated interactions are the primary cause of conductance enhancement.

A resonance appears 0.3 eV above the Fermi energy.

Abstract

We investigate the effects of lateral interactions on the conductance of two molecules connected in parallel to semi-infinite leads. The method we use combines a Green function approach to quantum transport with density functional theory for the electronic properties. The system, modeled after a self-assembled monolayer, consists of benzylmercaptane molecules sandwiched between gold electrodes. We find that the conductance increases when intermolecular interaction comes into play. The source of this increase is the indirect interaction through the gold substrate rather than direct molecule-molecule interaction. A striking resonance is produced only 0.3 eV above the Fermi energy.