Electron transport through a metal-molecule-metal junction

TL;DR

This study investigates electron transport in metal-molecule-metal junctions using bisthiolterthiophene molecules, revealing non-linear I-V characteristics and conductance switching influenced by electrode spacing, analyzed through tunneling models.

Contribution

It provides experimental data on I-V characteristics of bisthiolterthiophene junctions and discusses their behavior using tunneling transport models considering molecular electronic spectra.

Findings

Zero bias conductance in 10-100 nS range

Reproducible non-linear I-V curves with step-like features

Switching of I-V characteristics by changing electrode distance

Abstract

Molecules of bisthiolterthiophene have been adsorbed on the two facing gold electrodes of a mechanically controllable break junction in order to form metal-molecule(s)-metal junctions. Current-voltage (I-V) characteristics have been recorded at room temperature. Zero bias conductances were measured in the 10-100 nS range and different kinds of non-linear I-V curves with step-like features were reproducibly obtained. Switching between different kinds of I-V curves could be induced by varying the distance between the two metallic electrodes. The experimental results are discussed within the framework of tunneling transport models explicitly taking into account the discrete nature of the electronic spectrum of the molecule.