title: Site-Selection in Single-Molecule Junction for Highly Reproducible Molecular Electronics.
abstract: Adsorption sites of molecules critically determine the electric/photonic properties and the stability of heterogeneous molecule-metal interfaces. Then, selectivity of adsorption site is essential for development of the fields including organic electronics, catalysis, and biology. However, due to current technical limitations, site-selectivity, i.e., precise determination of the molecular adsorption site, remains a major challenge because of difficulty in precise selection of meaningful one among the sites. We have succeeded the single site-selection at a single-molecule junction by performing newly developed hybrid technique: simultaneous characterization of surface enhanced Raman scattering (SERS) and current-voltage (I-V) measurements. The I-V response of 1,4-benzenedithiol junctions reveals the existence of three metastable states arising from different adsorption sites. Notably, correlated SERS measurements show selectivity toward one of the adsorption sites: "bridge sites". This site-selectivity represents an essential step toward the reliable integration of individual molecules on metallic surfaces. Furthermore, the hybrid spectro-electric technique reveals the dependence of the SERS intensity on the strength of the molecule-metal interaction, showing the interdependence between the optical and electronic properties in single-molecule junctions.
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kaneko
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Daigo
authors.initials: D
authors.lastname: Murai
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Santiago
authors.initials: S
authors.lastname: Marqués-González
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komoto
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Nishino
authors.affiliation: Department of Mechanical Engineering, Nagoya Institute of Technology , Gokiso, Showa, Nagoya 466-8555, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: WPI Center for Materials Nanoarchitechtonics (WPI-MANA), National Institute for Materials Science , Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tsukagoshi
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology , 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kiguchi