Large negative differential resistance in triangular and square cyclopropyllithium derivative molecule

Different from hexagon-based carbon structures, the recently synthesized cyclopropyllithium derivative molecule of [{μ-c-CSiMe3C2H4}Li]4 possesses both triangular and quadrilateral rings, which is expected to exhibit interesting electronic features. Based on first-principles calculations, the electronic transport of this molecule contacted with carbon linear chain electrodes is investigated. Large negative differential resistance (NDR) phenomenon is observed. Moreover, the NDR is found to be robust to the doping on side branches which are perpendicular to the transport direction, but sensitive to the doping on main branches, which has a great influence on the NDR. NDR is found in all the doping cases, suggesting it is the intrinsic feature of such systems. Further analysis shows that, it is the suppression of the transmission peak induced by the change of energy states from delocalization to localization around the Fermi level that triggers the NDR. Our findings may throw light on the development of future molecular devices. •Large negative differential resistance (NDR) is observed in the single-molecule level.•NDR is robust to the doping on side branches which are perpendicular to the transport direction.•NDR is sensitive to the doping on main branches which are parallel to the transport direction.•The decay of delocalization of the states triggers the NDR.