Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 44: Poster Session II (Semiconductors; Oxides and Insulators: Adsorption, Clean Surfaces, Epitaxy and Growth; Surface Chemical Reactions and Heterogeneous Catalysis; Surface or Interface Magnetism; Solid-Liquid Interfaces; Organic, Polymeric, Biomolecular Films; Particles and Clusters; Methods: Atomic and Electronic Structure; Time-resolved Spectroscopies)

O 44.56: Poster

Mittwoch, 28. März 2007, 17:00–19:30, Poster C

Controlling molecular adsorption through domain-patterned lithium niobate — •Alexander Haußmann, Marc Tobias Wenzel, Stefan Grafström, Thomas Härtling, Christian Loppacher, and Lukas Eng — Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden

Recent progress in engineering ferroelectric domains has led to the possibility of creating domain patterns on the submicron scale. Because the domain arrangement corresponds to a pattern of opposite surface charges, such structured ferroelectric materials promise interesting applications as templates for the structured adsorption of charged molecules on surfaces. Recent work has reported on the adsorption of noble-metal nanoparticles [1] to such surfaces. Here, we report on the adsorption of λ-DNA to LiNbO₃ single-crystal surfaces. The DNA molecules of some 10 µm in length were marked with the fluorescent dye yoyo-1 to facilitate optical tracking of the their distribution on the surface. We found that λ-DNA preferentially adsorbs to c⁺ domains. The recently discovered reduction of the coercive field of LiNbO₃ under UV illumination [2] offers a promising way for writing arbitrary domain patterns on the micrometer scale. Here, we will report first results on the switching and adsorption behavior observed in a setup in which the sample is mounted in a liquid cell and a focused He-Cd laser beam (at λ = 325 nm) is used for UV patterning.

[1] J. L. Giocondi and G. S. Rohrer, Chem. Mater. 13, 241 (2001)

[2] M. Müller, E. Soergel, K. Buse, Appl. Phys. Lett. 83, 1824 (2003)