Structural and electron transport investigations of functionalized carboxylic acids on Cu(110)-
surfaces: experimental and ab initio studies

Dr. Ing. Silvia Karthäuser, Research Center Jülich [Homepage]

Dr. Nicolae Atodiresei, Research Center Jülich [Homepage]

Prof. Dr. Stefan Blügel, Research Center Jülich [Homepage]

Our aim is to investigate the detailed structure and the electronic transport through the carboxylate-
Cu(110) interface, experimentally and theoretically, and to use these data to build up a molecular
device, which is based on the exploitation of the different electron transport paths through these
molecules. The environmental coupling and electron transport properties will be investigated using
the carboxylic acids with systematically varying substituents adsorbed in different configurations on
Cu(110) to deduce the influence of the HOMO/LUMO gap on the intermolecular and moleculesubstrate
coupling. Experimentally we aim to combine differential conductance measurements and
inelastic tunneling spectroscopy with high resolution UHV-STM to get the energy levels and the
electron-phonon coupling of the carboxylic acids in a thoroughly defined environment. Theoretically
we aim at combining ab initio methods to describe structural and transport properties and to deduce
the theoretical parameters to predict structures of carboxylic acids, which are stable in two
conductive states so that they have the potential to be used as electronic devices. Furthermore we
intend to chemically modify the carboxylic monolayers or embed single molecules in situ. Finally we
will use the electron transport through the intermolecular π-π interaction of carboxylic acids to
modulate the electron transport vertical through the molecule and to build up a molecular device.