title: Barrier formation and charging energy for a variable nanogap organic molecular junction: a tip/C60/Au(111) configuration.
abstract: We analyze the nanogap organic molecular junction formed by a C(60) molecule in between an Au-tip and an Au(111)-surface. In our approach, we first calculate the atomic geometry of the tip/C(60)/Au(111) nanocontact as a function of the tip-surface distance and molecule adsorption site using a density functional theory-local density approximation (DFT-LDA) technique. The electronic structure and metal/organic barrier height formation (for a single molecule) are analyzed using the induced density of interface states model for metal/organic interfaces. From this analysis we calculate the charging energy U(eff) of the C(60) molecule at the nanocontact and determine self-consistently the transport energy gap and the organic molecule density of states. Our results are shown to be in good agreement with the experimental evidence.
authors.affiliation: Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain. enrique.abad@uam.es
authors.forename: E
authors.initials: E
authors.lastname: Abad
authors.forename: J I
authors.initials: JI
authors.lastname: Martínez
authors.forename: J
authors.initials: J
authors.lastname: Ortega
authors.forename: F
authors.initials: F
authors.lastname: Flores