Low Temperature Electronic Transport through Macromolecules and Characteristics of Intramolecular Electron Transfer

TL;DR

This paper presents a theoretical analysis of low-temperature electronic transport in macromolecules, revealing how step-like current-voltage features can inform on intramolecular electron transfer mechanisms and pathways.

Contribution

It introduces a coherent tunneling model for low-temperature electron transfer in macromolecules and analyzes dephasing effects using the Buttiker model, linking theory with experimental data.

Findings

Step-like structures in I-V curves indicate ET pathways.

Dephasing effects can be minimized to observe transmission features.

Analytical and numerical results support the model's predictions.

Abstract

A theory of electronic transport through molecular wires is applied to analyze characteristics of a long-range electron transfer (ET) through molecular bridges in macromolecules with complex donor/acceptor subsystems. Assuming a coherent electron tunneling through the bridge to be the predominant mechanism of ET at low temperatures it is shown that low temperature current-voltage curves can exhibit a step-like structure, which contains information concerning intrinsic features of ET processes such as the effect of donor/acceptor coupling to the bridge and primary pathways of electrons tunneling through the bridge. By contacting the proposed theoretical analysis with such experimental data a variety of valuable characteristics of long-range intramolecular ET can be identified. Analytical and numerical results are presented. Using the Buttiker dephasing model within the scattering matrix formalism we analyze dephasing effects, and we show that these effects could be reduced enough to allow the structure of the electron transmission function to be exposed in the experiments on the electronic transport through macromolecules.