Dresden 2009 – scientific programme
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SYSO: Symposium Self-organizing Surfaces and Interfaces
SYSO 3: Self-Organizing Surfaces and Interfaces - Posters
SYSO 3.19: Poster
Wednesday, March 25, 2009, 17:30–19:30, P3
Influence of molecule adsorption on the surface electric fields of GaAs(001)c(4x4) and (2x4) — •T. Bruhn1,2, R. Passmann1,2, B.O. Fimland3, M. Kneissl1, N. Esser1,2, and P. Vogt1 — 1TU Berlin, Institut für Festkörperphysik, Hardenbergstr.36, 10623 Berlin, Germany — 2ISAS Berlin, Albert-Einstein-Str.9, 12489 Berlin, Germany — 3NUST, NO-7491 Trondheim, Norway
Organic/inorganic interfaces have been attracting a growing interest over the last years. Particularly the affection of surface electric fields due to molecular adsorption could open up perspectives for novel sensor concepts. For these purposes a profound understanding of the atomic and electronic properties of the interface formation is required.
In our experiments we have been investigating the interface between different the GaAs(001)c(4x4) and (2x4) surface reconstructions and self-assambled monolayers of small organic ring molecules (Cyclopentene (C5H8) and 1,4-Cyclohexadiene (C6H8)). The samples were prepared in UHV and investigated with reflectance anisotropy spectroscopy (RAS) and soft x-ray photoelectron spectroscopy (SXPS).
After the chemisorption of the molecules a significant influence on the linear electro-optic effect (LEO) could be observed. This influence could be shown to also depend on the substrate doping level. On both substrate surface reconstructions photoemission spectra of the Ga 3d and As 3d core levels exhibit a different influence on the surface band bending. These results can be explained by an affection of reconstruction induced piezo-electric fields due to the molecule adsorption.