title: Orientational ordering of nonplanar phthalocyanines on Cu(111): strength and orientation of the electric dipole moment.
abstract: In order to investigate the orientational ordering of molecular dipoles and the associated electronic properties, we studied the adsorption of chlorogallium phthalocyanine molecules (GaClPc, Pc=C32N8H16(-2) on Cu(111) by using the x-ray standing wave technique, photoelectron spectroscopy, and quantum mechanical calculations. We find that for submonolayer coverages on Cu(111) the majority of GaClPc molecules adsorb in a Cl-down configuration by forming a covalent bond to the substrate. For bilayer coverages the x-ray standing wave data indicate a coexistence of the Cl-down and Cl-up configurations on the substrate. The structural details established for both cases and supplementary calculations of the adsorbate system allow us to analyze the observed change of the work function.
authors.affiliation: Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany. alexander.gerlach@uni-tuebingen.de
authors.forename: A
authors.initials: A
authors.lastname: Gerlach
authors.forename: T
authors.initials: T
authors.lastname: Hosokai
authors.forename: S
authors.initials: S
authors.lastname: Duhm
authors.forename: S
authors.initials: S
authors.lastname: Kera
authors.forename: O T
authors.initials: OT
authors.lastname: Hofmann
authors.forename: E
authors.initials: E
authors.lastname: Zojer
authors.forename: J
authors.initials: J
authors.lastname: Zegenhagen
authors.forename: F
authors.initials: F
authors.lastname: Schreiber