Document Type: Research Paper
Solid State Physics Department, University of Mazandaran, Babolsar, I. R. Iran Molecular Electronics Lab., University of Mazandaran, Babolsar, I. R. Iran
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.