title: Role of stress on charge transfer through self-assembled alkanethiol monolayers on Au.
abstract: We have studied charge transfer through alkanethiol molecules self-assembled on Au(111) substrates using interfacial force microscopy. Simultaneous measurement of the tip-substrate current and the normal interfacial force reveals the critical role of tip-film contact. Measurable currents are seen only for tip-applied stresses above about 20 MPa, after which the current rises exponential with stress. We suggest that charge transfer results from stress-induced band-gap states near the Fermi level in these normally highly insulating molecular films.
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185-1415, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Son
authors.forename: H I
authors.initials: HI
authors.lastname: Kim
authors.forename: J E
authors.initials: JE
authors.lastname: Houston