title: Self-assembled nanogaps for molecular electronics.
abstract: A nanogap for molecular devices was realized using solution-based self-assembly. Gold nanorods were assembled to gold nanoparticle-coated conducting SnO2:Sb nanowires via thiol end-capped oligo(phenylenevinylene)s (OPVs). The molecular gap was easily created by the rigid molecule itself during self-assembly and the gap length was determined by the molecule length. The gold nanorods and gold nanoparticles, respectively covalently bonded at the two ends of the molecule, had very small dimensions, e.g. a width of approximately 20 nm, and hence were expected to minimize the screening effect. The ultra-long conducting SnO2:Sb nanowires provided the bridge to connect one of the electrodes of the molecular device (gold nanoparticle) to the external circuit. The tip of the atomic force microscope (AFM) was contacted onto the other electrode (gold nanorod) for the electrical measurement of the OPV device. The conductance measurement confirmed that the self-assembly of the molecules and the subsequent self-assembly of the gold nanorods was a feasible method for the fabrication of the nanogap of the molecular devices.
authors.affiliation: Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen, Denmark.
authors.forename: Qingxin
authors.initials: Q
authors.lastname: Tang
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Tong
authors.forename: Titoo
authors.initials: T
authors.lastname: Jain
authors.forename: Tue
authors.initials: T
authors.lastname: Hassenkam
authors.forename: Qing
authors.initials: Q
authors.lastname: Wan
authors.forename: Kasper
authors.initials: K
authors.lastname: Moth-Poulsen
authors.forename: Thomas
authors.initials: T
authors.lastname: Bjørnholm
mesh_terms: D003460:Crystallization / Q000379:methods; D004553:Electric Conductivity; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008839:Microelectrodes; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000295:instrumentation*; D010316:Particle Size; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D017971:Tin Compounds; D006046:Gold; C045358:stannic oxide