The role of impurities on the properties of electron transport through the metal/trans-PA/metal system: Green's function approach

In this work, we present a theoretical study on the conductance of trans-polyacetylene (trans-PA) nanowire in the presence of impurities and use of trans-PA as a molecular bridge sandwiched between two semi-infinite metallic electrodes with a simple cubic structure and square cross section. We use a tight-binding Hamiltonian model within the framework of a generalized Green's function technique and rely on the Landauer-Butikker formalism as the basis for studying the current-voltage characteristic of this system. Our calculations indicate that the presence of impurities gives rise to significant enhancement in the density of states within the bandgap and large enhancement in conductance and the current-voltage characteristic. Also our results show that the electronic properties of the system are sensitive to the molecule-to-impurity coupling strength. (C) 2010 Elsevier B.V. All rights reserved.