Dresden 2009 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
O: Fachverband Oberflächenphysik
O 27: Poster Session I (Methods: Scanning probe techniques; Methods: Atomic and electronic structure; Methods: Molecular simulations and statistical mechanics; Oxides and Insulators: Clean surfaces; Oxides and Insulators: Adsorption; Oxides and Insulators: Epitaxy and growth; Semiconductor substrates: Clean surfaces; Semiconductor substrates: Epitaxy and growth; Semiconductor substrates: Adsorption; Nano- optics of metallic and semiconducting nanostructures; Electronic structure; Methods: Electronic structure theory; Methods: other (experimental); Methods: other (theory); Solutions on surfaces; Epitaxial Graphene; Surface oder interface magnetism; Phase transitions; Time-resolved spectroscopies)
O 27.41: Poster
Tuesday, March 24, 2009, 18:30–21:00, P2
Scanning Tunneling Microscopy and Spectroscopy of Phthalocyanine Molecules on Insulating Films — •Christof Uhlmann1, Maurice Ziola1, Niko Pavliček1, Tobias Sonnleitner1, Gerhard Meyer2, and Jascha Repp1,2 — 1Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany — 2IBM Research, Zurich Research Laboratory, CH-8803 Rüschlikon, Switzerland
Ultrathin insulating films on metal substrates facilitate the use of the scanning tunneling microscope to study the electronic properties of individual molecules, which are electronically decoupled from the metallic substrate. This geometry represents a double-barrier tunneling junction, in which at the resonances in conductance spectra an electron is temporarily added to or removed from the molecule. To gain a detailed understanding of the spectra, it is desirable to systematically vary the electronic structure of molecules step by step without changing the geometrical structure too strongly. We addressed this issue by studying a series of metal-phthalocyanine molecules. In this series, the lowest unoccupied (LUMO) and the highest occupied molecular orbital (HOMO) can differ greatly in symmetry for the different metal cores [1]. In addition to the variation of the electronic structures of the molecule itself we also varied the level alignment with respect to the Fermi level. The latter was done by varying the substrate system, which is accompanied by a variation in the work-function.
[1] M.-S. Liao and S. Scheiner, J. Chem. Phys. 114, 9780 (2001).