Ab initio study of molecule transport characteristics based on nonequilibrium Green’s function theory

We use a self-consistent method to study phenyl dithiol transport from the first-principles calculations. The calculated current and differential conductance are supported by the famous experimental results [ Reed et al. Science 278 252 (1997)]. We investigate the coupling effects between the sulfur atom and the metal surface by adjusting their distance in a very small range, and find that the charge carriers responsible for the initial rise of the current can be changed from holes to electrons. We calculate the I-V behaviors of the naphthalene-dithiol and anthracene-dithiol dressed by the gold electrodes. The numerical results present the quantum behaviors that are in agreement with the recent experiments for the anthrylacetylene by Zareie et al. Nano Lett. 3 139 (2003)].