title: Evaluation of the Electronic Structure of Single-Molecule Junctions Based on Current-Voltage and Thermopower Measurements: Application to C60Single-Molecule Junction.
abstract: The electronic structure of molecular junctions has a significant impact on their transport properties. Despite the decisive role of the electronic structure, a complete characterization of the electronic structure remains a challenge. This is because there is no straightforward way of measuring electron spectroscopy for an individual molecule trapped in a nanoscale gap between two metal electrodes. Herein, a comprehensive approach to obtain a detailed description of the electronic structure in single-molecule junctions based on the analysis of current-voltage (I-V) and thermoelectric characteristics is described. It is shown that the electronic structure of the prototypical C60single-molecule junction can be resolved by analyzing complementary results of the I-V and thermoelectric measurement. This combined approach confirmed that the C60single-molecule junction was highly conductive with molecular electronic conductances of 0.033 and 0.003 G0and a molecular Seebeck coefficient of -12 μV K-1. In addition, we revealed that charge transport was mediated by a LUMO whose energy level was located 0.5≈0.6 eV above the Fermi level of the Au electrode.
authors.affiliation: Department of Chemistry, Graduate School of Science, 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, Tokyo Institute of Technology, 2-12-1 W4-10 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Isshiki
authors.affiliation: Department of Chemistry, Graduate School of Science, 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, 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 Chemistry, Graduate School of Science, 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
keywords: electron transport; electronic structure; fullerenes; single-molecule junction; thermopower