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.