title: Energy alignment induced negative differential resistance: the role of hybrid states in aromatic molecular devices.
abstract: Hybridization in aromatic molecules plays an important role in determining their electron transport properties. When an sp(2) bonded aromatic ring hybridizes with a carbon pair in either sp(3), sp(2), or sp form, only sp(2) and sp result in a delocalized state across the whole molecule, opening a channel for transport. At the same time negative differential resistance (NDR) is found only in the sp(2) and sp cases. An energy alignment scheme is adopted to elucidate the NDR process. This is constructed by comparing the positions of frontier molecular levels and the states of leads. It is revealed that the alignment between lead states located around the Fermi energy with the lowest unoccupied molecular orbital of the central molecule is the main cause of the NDR.
authors.affiliation: Nano-organic Photoelectronic Laboratory, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Fan
authors.forename: R Q
authors.initials: RQ
authors.lastname: Zhang
authors.forename: A Reily
authors.initials: AR
authors.lastname: Rocha
authors.forename: Stefano
authors.initials: S
authors.lastname: Sanvito
mesh_terms: D000465:Algorithms; D001555:Benzene Derivatives / Q000737:chemistry*; D003198:Computer Simulation; D004583:Electrons; D008956:Models, Chemical; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001555:Benzene Derivatives; D013438:Sulfhydryl Compounds