A first principles study on transport properties of benzene-based molecular junctions: The effect of side groups and anchoring atoms

摘要

Using density functional theory in conjunction with the nonequilibrium Greens function technique, the electron transport through the substituted benzenedithiol molecules inserted between two gold electrodes was investigated. We calculated the currentvoltage characteristics for positive and negative bias voltages. It was found that due to interaction with the applied electric field, the currentvoltage curve of amino substituted benzene molecule is asymmetric and exhibited switching behavior. Despite the asymmetric structure of benzene molecule substituted with hydroxyl group, there was no obvious rectification behavior in its currentvoltage curve, but a peak and a valley were observed in its currentvoltage characteristics. Furthermore, we calculated the currentvoltage curve for benzenediselenol and found that the best anchoring atom depends on bias voltage.