On the electrostatic potential profile in biased molecular wires

A. Nitzan, M. Galperin, G.-L. Ingold, and H. Grabert

J. Chem. Phys. 117, 10837–10841 (2002) DOI: 10.1063/1.1522406

The potential profile across a biased molecular junction is calculated within the framework of a simple Thomas-Fermi type screening model. In particular, the relationship between this profile and the lateral molecular cross section is examined. We find that a transition from a linear potential profile to a potential that drops mainly near the molecule-metal contacts occurs with increasing cross section width, in agreement with numerical quantum calculations.