AVS 51st International Symposium
    Organic Films and Devices Wednesday Sessions
       Session OF+EM-WeM

Paper OF+EM-WeM7
OMBD of Organic Semiconductors on Metal Surfaces: Structural and Electronic Properties

Wednesday, November 17, 2004, 10:20 am, Room 304C

Session: Molecular and Organic Films and Devices - Electronics
Presenter: G. Witte, Ruhr-Universität Bochum, Germany
Authors: G. Witte, Ruhr-Universität Bochum, Germany
C. Wöll, Ruhr-Universität Bochum, Germany
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The promising potential of using organic semiconductor materials as active layers for organic electronic applications and the increasing interest in molecular electronics have expressed an urgent necessity of understanding the molecular microstructure and growth properties of ordered organic films. Of particular interest for the fabrication of thin films organic field effect transistors are polycyclic aromatic hydrocarbons which reveal a large variety of structures upon growth on inorganic substrates.@footnote 1@ Here we report results of a comprehensive growth study of pentacene and perylene films on various metal surfaces. By combining LEED, HAS, XPS, NEXAFS, TDS and AFM we were able to characterize the molecular microstructure developing upon film growth. In all cases a characteristic molecular reorientation from a substrate controlled interface phase towards a bulk-like thick film phase was obtained. On particular surfaces such as Cu(110) even epitaxial film growth was achieved.@footnote 2@@footnote 3@ The studied organic films revealed further a pronounced dewetting which favours the formation of crystalline islands upon deposition. Moreover, the electronic properties of thin pentacene films on various metal surfaces were characterized by UPS. It was found that the magnitude of the interface dipole moment is not directly related to the adsorption energy of the molecules at the metal surface but is caused to some extend by an exchange like coupling mechanism. @FootnoteText@ @footnote 1@ G. Witte and Ch. Wöll, J. Mat. Res. (focuss issue Organic Electronics, 2004).@footnote 2@ S. Lukas et. al., ChemPhysChem 5, 266 (2004).@footnote 3@ S. Söhnchen et al., J.Chem. Phys. in print (2004).