The effect of asymmetrical electrode on the transport properties of molecular devices

By applying nonequilibrium Green's functions in combination with the density functional theory, we have investigated the electronic transport properties of molecular devices consisting of the carbon atomic chain coupling with symmetry and asymmetry Au electrodes. The asymmetry Au electrodes systems display good rectifying behavior. The main origin of this phenomenon is that a molecular core coupling with asymmetry electrodes can generate two asymmetrical Schottky barriers at both extended molecule regions. This rectification is also explained by the calculated transmission spectrum and the spatial distribution of the LUMO and HOMO states.