Charge Transport Properties of Molecular Junctions built from Dithiol Polyenes

TL;DR

This paper investigates how charge transmission varies in molecular junctions made from dithiol polyenes, revealing non-monotonic behavior with molecule length and validating results with an analytic model.

Contribution

It introduces an ab initio method for calculating Green's functions in molecular junctions and compares these results with an analytic model for validation.

Findings

Transmission is not a monotonic function of molecule length.

Ab initio calculations align well with the analytic model.

Correlation space approximation impacts transmission results.

Abstract

We present a study of the charge transmission behavior of a series of dithiol polyenes in the context of molecular junctions. Using the Landauer theory and zero voltage approximation the Green's functions of the inserted molecules are calculated from a fully ab initio wave function based procedure. Various possibilities in approximating the correlation space are explored and quantitatively evaluated. Our results show that the transmission behavior of a molecular junction is not a monotonic function of the length of the employed molecule. Moreover we introduce the analytic solution of a suitable model system to countercheck the ab initio results and find a remarkable degree of correspondence.