Conductance-voltage characteristics of single molecule junction : in resonant tunneling regime

Abstract EN

Electronic transport characteristics through a single molecule junction are investigated by using the Keldysh non equilibrium Green function (NEGF) model.

The model consists of a molecular bridge (represented by a molecular orbital) attached with two free electron reservoirs (represents two metallic leads) and it is coupled with a vibrational degree of freedom (represents a molecular vibrational mode).

The behavior of the electronic transfer through the molecular junction becomes more clearly visible by studying of the conductance-voltage characteristics.

The numerical calculations are done based on this model to study the changes in conductance behavior through a single molecule junction in the resonant tunneling regime.

According to our results, the conductance-voltage characteristics are influenced by (I) the electron-vibration interaction, (II) the molecular bridge-leads coupling strength, (III) the junction temperature, and (IV) the molecular vibrational mode energy.

We conclude that the previous parameters have a significant role in determination of the electron conduction through the single-molecule junctions.

Especially, the conductance is very sensitive to the molecular bridge-leads coupling strength and the junction temperature.

These features provide important information about the study of the electronic transport phenomena in molecular junctions.

Keywords: Molecular junction; nonequilibrium Green function theory; electronic transport; conductance; electron-vibration couplin