title: Electromechanical and conductance switching properties of single oligothiophene molecules.
abstract: We have studied the electron transport and electromechanical properties of single oligothiophenes with three and four thiophene repeating units covalently linked to two Au electrodes. The four-repeating unit molecule is found to be more conductive than the three-repeating unit molecule. This unusual length dependence is due to the different electronic states of the molecules. Both molecules can be switched reversibly between a high and low conducting state by oxidizing and reducing the molecules using an electrochemical gate. The conductance of the molecules decreases upon stretching, which is attributed to a force-induced increase in the HOMO-LUMO gap.
authors.affiliation: Department of Electrical Engineering & The Center for Solid State Electronics Research, Arizona State University, Tempe, Arizona 85287, USA.
authors.forename: Bingqian Q
authors.initials: BQ
authors.lastname: Xu
authors.forename: Xiulan L
authors.initials: XL
authors.lastname: Li
authors.forename: Xiaoyin Y
authors.initials: XY
authors.lastname: Xiao
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakaguchi
authors.forename: Nongjian J
authors.initials: NJ
authors.lastname: Tao
mesh_terms: D004548:Elasticity; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D046911:Macromolecular Substances / Q000032:analysis / Q000737:chemistry; D019563:Mechanics; D020409:Molecular Motor Proteins / Q000737:chemistry*; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D012666:Semiconductors; D013314:Stress, Mechanical; D013876:Thiophenes / Q000032:analysis / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D020409:Molecular Motor Proteins; D013876:Thiophenes