Volume 8, Issue 11 p. 1707-1712
Article

The Molecular Orientation of para-Sexiphenyl on Cu(110) and Cu(110) p(2×1)O

Martin Oehzelt Dr.

Martin Oehzelt Dr.

Institute of Physics, Surface and Interface Physics, Karl-Franzens Universität Graz, Universitätsplatz 5, 8010 Graz, Austria, Fax: (+43) 316-380-9816

Current address: Institut für Experimentalphysik, Abteilung für Atom- und Oberflächenphysik, Johannes Kepler Universität Linz, Altenbergerstraße 69, 4040 Linz, Austria, Fax: (+43) 732-2468-8509

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Leonhard Grill Dr.

Leonhard Grill Dr.

Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany

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Stephen Berkebile

Stephen Berkebile

Institute of Physics, Surface and Interface Physics, Karl-Franzens Universität Graz, Universitätsplatz 5, 8010 Graz, Austria, Fax: (+43) 316-380-9816

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Georg Koller Dr.

Georg Koller Dr.

Institute of Physics, Surface and Interface Physics, Karl-Franzens Universität Graz, Universitätsplatz 5, 8010 Graz, Austria, Fax: (+43) 316-380-9816

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Falko P. Netzer Prof. Dr.

Falko P. Netzer Prof. Dr.

Institute of Physics, Surface and Interface Physics, Karl-Franzens Universität Graz, Universitätsplatz 5, 8010 Graz, Austria, Fax: (+43) 316-380-9816

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Michael G. Ramsey Prof. Dr.

Michael G. Ramsey Prof. Dr.

Institute of Physics, Surface and Interface Physics, Karl-Franzens Universität Graz, Universitätsplatz 5, 8010 Graz, Austria, Fax: (+43) 316-380-9816

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First published: 26 July 2007
Citations: 75

Graphical Abstract

Optimizing performance: The molecular orientation and growth of organic semiconductors can be steered by surface chemistry. Using the model compound para-sexiphenyl [see figure C36H24 on Cu(110) p(2×1)–O], the flexibility of organic molecules to adopt a given surface corrugation and their unique tilting, which releases stress, is demonstrated.

Abstract

Controlling the molecular growth of organic semiconductors is an important issue to optimize the performance of organic devices. Conjugated molecules, used as building blocks, have an anisotropic shape and also anisotropic physical properties like charge transport or luminescence. The main challenge is to grow highly crystalline layers with molecules of defined orientation. The higher the crystallinity, the closer these properties reach their full intrinsic potential, while the orientation determines the physical properties of the film. Herein we show that the molecular orientation and growth can be steered by the surface chemistry, which tunes the molecule–substrate interaction. In addition, the oxygen reconstruction of the surface, demonstrates the flexibility of the organic molecules to adopt a given surface corrugation and their unique possibility to release stress by tilting.