Regensburg 2007 – scientific programme

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SYOE: Symposium Organic Thin Film Electronics: From Molecular Contacts to Devices

SYOE 8: Poster Session SYOE

SYOE 8.7: Poster

Tuesday, March 27, 2007, 18:00–20:00, Poster B

Structural properties and scanning tunneling data of a monolayer of PTCDA on the Ag(111) surface — •Michael Rohlfing — Fachbereich Physik, Universität Osnabrück

The adsorption of a monolayer of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) on the Ag(111) surface constitutes one of the best studied adsorption systems of organic molecules on metals [1]. Here we present density-functional calculations of this prototypical systems, yielding detailed insight into its structural properties. Using the local-density approximation as the best choice for the exchange-correlation functional, we discuss the bond lengths inside the molecules, their distortion due to adsorption, and their position and orientation relative to the substrate and to each other. Based on the obtained geometric and electronic structure we calculate scanning-tunneling microscopy and spectroscopy data within the Tersoff-Hamann framework. To this end, two-dimensional Fourier transform methods and spatial extrapolation techniques are employed to evaluate the sample wave functions at the tip position. We obtain constant-current images and spectral data that reveal detailed information about the electronic structure of the system.

[1] A. Kraft, R. Temirov, S. K. M. Henze, S. Soubatch, M. Rohlfing, and F. S. Tautz, Phys. Rev. B 74, 041402(R) (2006).