Negative differential resistance behaviors in OPE derivatives combined C60 molecular junctions modulated with side groups

Abstract

By applying non-equilibrium Green’s functions (NEGF) in combination with the density functional theory (DFT), we investigate the electronic transport properties of molecular junctions constructed by OPE derivatives with different side groups combined C60 molecules. The results show that the side groups play an important role in the properties of electron transport. Negative differential resistance (NDR) is observed in such devices. Especially for the molecule with electron-donating group (−OCH3), two NDR appear at different bias voltage regions. And the mechanism is proposed for the NDR behavior, owing to the shift of the molecular orbitals caused by the change in molecule charge.