Quantum transport through molecular wires

TL;DR

This study investigates electron transport in heterocyclic molecular wires using Green's function and tight-binding models, revealing how heteroatoms and coupling strength affect conductance and current-voltage characteristics.

Contribution

It provides a detailed analysis of how heteroatoms and coupling strength influence electron transport in molecular wires, using Green's function and tight-binding models.

Findings

Transport properties are significantly affected by heteroatoms.

Resonance peaks in conductance are sharp in weak coupling and broaden in strong coupling.

Current-voltage characteristics reveal key features of molecular transport.

Abstract

We explore electron transport properties in molecular wires made of heterocyclic molecules (pyrrole, furan and thiophene) by using the Green's function technique. Parametric calculations are given based on the tight-binding model to describe the electron transport in these wires. It is observed that the transport properties are significantly influenced by (a) the heteroatoms in the heterocyclic molecules and (b) the molecule-to-electrodes coupling strength. Conductance ($g$) shows sharp resonance peaks associated with the molecular energy levels in the limit of weak molecular coupling, while they get broadened in the strong molecular coupling limit. These resonances get shifted with the change of the heteroatoms in these heterocyclic molecules. All the essential features of the electron transfer through these molecular wires become much more clearly visible from the study of our current-voltage ($I$-$V$) characteristics, and they provide several key informations in the study of molecular transport.