Site effect of impurity based on a bimolecular tunneling rectifier

This paper uses first-principles methods to describe a bimolecular tunneling rectifier comprised of benzene and cofacial cyclobutadiene and sandwiched between two Au electrodes, and the site effect of atomic impurity on its electron transport. The methods used are based on density functional theory and non-equilibrium Green's function. We compare the difference in the rectifier's tunneling characteristics when it has atomic purity and at different sites of impurity. The results reveal that the site effect can enhance, weaken or reverse the rectification behavior. The analytical results of the transmission spectrum, electrostatic difference potential and the eigenstates give us a vivid view of the electron transport in current. Copyright © 2011 American Scientific Publishers.