i-v characteristics of a molecular wire of polyaniline (emeraldine base)

in this study, polyaniline molecule (emeraldine base) is modeled as a molecular wire and the effects of the metal/molecule coupling strength and the molecule length on the current-voltage (i-v) characteristics are numerically investigated. using a tight-binding hamiltonian model, the methods based on non-equilibrium green’s function theory, landauer formalism and newns-anderson model, our calculations indicate that the i-v curve has the step-like form and the current is very sensitive to the metal/molecule coupling strength. a negative differential resistance region is also exhibited after second voltage step in the i-v curves and the line slope at that region is studied as a function of two parameters, which are the metal/molecule coupling strength and the molecule length.