Tunneling of electrons via rotor-stator molecular interfaces: combined ab initio and model study

TL;DR

This study combines ab initio calculations and modeling to analyze electron tunneling through rotor-stator molecular interfaces, revealing how molecular structure and conformation influence electronic transport properties and transition voltages.

Contribution

It introduces a combined ab initio and model approach to study tunneling barriers and conformational effects in rotor-stator molecules, highlighting geometry-dependent transport.

Findings

Presence of aldehyde enhances bistability and transport properties.

Conformational dependence significantly affects tunneling current.

Low-voltage field emission observed due to molecular conformation.

Abstract

Tunneling of electrons through rotor-stator anthracene aldehyde molecular interfaces is studied with a combined ab initio and model approach. Molecular electronic structure calculated from first principles is utilized to model different shapes of tunneling barriers. Together with a rectangular barrier, we also consider a sinusoidal shape that captures the effects of the molecular internal structure more realistically. Quasiclassical approach with the Simmons' formula for current density is implemented. Special attention is paid on conformational dependence of the tunneling current. Our results confirm that the presence of the side aldehyde group enhances the interesting electronic properties of the pure anthracene molecule, making it a bistable system with geometry dependent transport properties. We also investigate the transition voltage and we show that confirmation dependent field emission could be observed in these molecular interfaces at realistically low voltages. The present study accompanies our previous work where we investigated the coherent transport via strongly coupled delocalized orbital by application of Non-equilibrium Green's Function Formalism.