title: Ultrafast Charge Transfer Pathways Through A Prototype Amino-Carboxylic Molecular Junction.
abstract: Charge transport properties of a vertically stacked organic heterojunction based on the amino-carboxylic (A-C) hydrogen bond coupling scheme are investigated by means of X-ray resonant photoemission and the core-hole clock method. We demonstrate that hydrogen bonding in molecular bilayers of benzoic acid/cysteamine (BA/CA) with an A-C coupling scheme opens a site selective pathway for ultrafast charge transport through the junction. Whereas charge transport from single BA layer directly coupled to the Au(111) is very fast and it is mediated by the phenyl group, the interposition of an anchoring layer of CA selectively hinders the delocalization of electrons from the BA phenyl group but opens a fast charge delocalization route through the BA orbitals close to the A-C bond. This evidences that hydrogen bonding established upon A-C recognition can be exploited to spatially/orbitally manipulate the charge transport properties of heteromolecular junctions.
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana , Jadranska ul. 19, 1000 Ljubljana, Slovenia.
authors.forename: Gregor
authors.initials: G
authors.lastname: Kladnik
authors.affiliation: Dipartimento di Fisica, Università di Trieste , via A. Valerio 2, I-34127 Trieste, Italy.|CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Puppin
authors.affiliation: CNR-ISM, UOS Trieste , Area Science Park Basovizza, 34149 Trieste, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Coreno
authors.affiliation: CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: de Simone
authors.affiliation: CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Floreano
authors.affiliation: CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Verdini
authors.affiliation: Dipartimento di Fisica, Università di Trieste , via A. Valerio 2, I-34127 Trieste, Italy.|CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Morgante
authors.affiliation: Faculty of Mathematics and Physics, University of Ljubljana , Jadranska ul. 19, 1000 Ljubljana, Slovenia.
authors.forename: Dean
authors.initials: D
authors.lastname: Cvetko
authors.affiliation: CNR-IOM Laboratorio TASC , Basovizza SS-14, km 163.5, I-34012 Trieste, Italy.
authors.forename: Albano
authors.initials: A
authors.lastname: Cossaro
mesh_terms: D019817:Benzoic Acid / Q000737:chemistry*; D003543:Cysteamine / Q000737:chemistry*; D004579:Electron Transport; D006046:Gold / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D013499:Surface Properties
chemical_list: D003543:Cysteamine; D006046:Gold; D019817:Benzoic Acid
keywords: Organic heterojunction; amino-carboxylic; charge transport; core-hole-clock; hydrogen bond; resonant photoemission