Torsion angle dependence of the rectifying performance in molecular device with asymmetrical anchoring groups

Using first-principles density functional theory and nonequilibrium Green's function formalism, we investigate the effect of torsion angle on the rectifying characteristics of 4′-thiolate-biphenyl-4-dithiocarboxylate sandwiched between two Au(111) electrodes. The results show that the torsion angle has an evident influence on rectifying performance of such devices. By increasing the dihedral angle between two phenyl rings, namely changing the magnitude of the intermolecular coupling effect, a different rectifying behavior can be observed in these systems. Our findings highlight that the rectifying characteristics are intimately related to dihedral angles and can provide fundamental guidelines for the design of functional molecular devices.