AVS 47th International Symposium
    Organic Films and Devices Thursday Sessions
       Session OF+EL+SS-ThM

Paper OF+EL+SS-ThM1
Highly Ordered Layers of Large Conjugated @pi@-systems on Cu(111): A Novel Preparation Method

Thursday, October 5, 2000, 8:20 am, Room 313

Session: Organic Thin Films
Presenter: G. Beernink, Ruhr-Universität Bochum, Germany
Authors: G. Beernink, Ruhr-Universität Bochum, Germany
K. Weiss, Ruhr-Universität Bochum, Germany
A. Birkner, Ruhr-Universität Bochum, Germany
F. Dötz, Max-Planck-Institut für Polymerforschung, Germany
K. Müllen, Max-Planck-Institut für Polymerforschung, Germany
C. Wöll, Ruhr-Universität Bochum, Germany
Correspondent: Click to Email
With regard to applications in molecular electronics and the fabrication of nanoelectronic devices, polycyclic aromatic hydrocarbons (PAH), e.g. the graphite segment hexa-peri-hexabenzocoronene (HBC), have recently received considerable attention. For such large PAHs, however, the low solubility in organic or polar solvents and the rather large sublimation temperatures make the application of the commonly used deposition methods, namely adsorption from solution or evaporation in a vacuum system (CVD, OMBE) difficult or even impossible. In this work, we present a direct way to synthesize one particular polycyclic aromatic hydrocarbon, namely hexa-peri-hexabenzocoronene (HBC) by using a surface as a template. A modified precursor molecule, 1,2,3,4,5,6-Hexakis(4-dodecyloxyphen-1-yl)benzene (HPB), which is not planar, is evaporated on a Cu(111) surface. Heating of the substrate leads via thermally induced cyclodehydrogenation to the product HBC, which is characterized by XPS, X-ray absorption spectroscopy (NEXAFS) and STM. The NEXAFS-data directly demonstrate the formation of flat, graphite-like segments which interact only weakly with the substrate, whereas the STM data reveal a high of lateral order.