Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 21: FV-internes Symposium „Optische Spektroskopie von dünnen Schichten und Grenzfl
ächen"

DS 21.3: Hauptvortrag

Dienstag, 8. März 2005, 11:15–12:00, TU HS110

Optical analysis of monolayers at surfaces and interfaces — •V. Wagner — School of Engineering and Science, International University Bremen, Campus Ring 8, D-28759 Bremen, Germany

Controlling of surface and interface properties is crucial for tailoring advanced materials, especially if the structure size in one or more dimensions approaches the nanoscale regime. Thus, analysis and modification of the last atomic layer is of crucial importance. Optical probes offer the advantage of high spectral resolution and the possibility to analyze under liquid, vapor and vacuum environments. With emphasis on Raman spectroscopy and modulation spectroscopy various examples of analysis of structural and binding properties of such monolayers are discussed. Especially materials used in electronic applications, i.e. organic and inorganic semiconductors, are addressed. It is demonstrated how the orientation of surface reconstructions of II-VI semiconductors are determined by Raman spectroscopy or the modification of bonding properties is sensed of organic molecules, e.g. 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) on top of metallic silver surfaces. Furthermore, modulation spectroscopy is applied to follow the changes of the electronic properties and provides complementary information to the vibrational data obtained by Raman scattering.