Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 58: Organic-Inorganic Systems III: Metal-Organics
O 58.4: Vortrag
Mittwoch, 9. März 2016, 15:45–16:00, S054
A new perspective on the adsorption behavior of nonplanar phthalocyanines on Cu(111) — •Elisabeth Wruss1, Shashank S. Harivyasi1, David A. Egger2, Oliver T. Hofmann1, Elisabeth Verwuester1, Alexander Gerlach3, Nahid Ilyas4, Frank Schreiber3, Oliver L. A. Monti4, and Egbert Zojer1 — 1Graz University of Technology, Graz, Austria. — 2Weizmann Institute of Science, Rehovoth, Israel. — 3Universität Tübingen, Tübingen, Germany — 4University of Arizona, Tucson, USA
The geometric and electronic properties of nonplanar, chlorinated members of the phthalocyanine family, namely chlorogallium phthalocyanine and chloroboron subphthalocyanine upon adsorption on Cu(111) are investigated, using DFT simulations including the vdW-surf correction. The comparison with experimental results including x-ray standing wave, ultraviolet photoelectron spectroscopy and scanning tunneling microscopy yields strong indications of a dissociation of the molecules upon adsorption associated with a loss of the Cl atom as one possible scenario. For the chlorogallium phthalocyanine system, the experimental and calculated adsorption heights and adsorption-induced work-function shifts yield good quantitative agreement. Surprisingly, the same work-function change is also found for the adsorption of intact "Cl-down" molecules, despite hugely different geometries and molecular dipoles. This seeming contradiction can be explained as a consequence of Fermi-level pinning. Our findings show that the adsorption process of chlorinated phthalocyanines and related molecules is considerably more complex than previously assumed.