Current–voltage characteristics of single molecular junction: Dimensionality of metal contacts

Formalisms for current–voltage (I–V) characteristics of a single molecular junction with electrodes possessing one-, two-, and three-dimensional energy distributions are derived and compared in the framework of elastic scattering theory. Model calculations on a device constituted of 1,4 benzene-dithiolate molecule chemically bonded to two gold electrodes are carried out using hybrid density functional theory. It is shown that the dimensionality of metal contacts has a strong effect on the I–V characteristics of the molecular junction, in particular the shape of the conductance curves. Good agreement with experimental I–V curves has been found for the case of the three-dimensional electron system.