AVS 50th International Symposium
    Contacts to Organic Materials Topical Conference Tuesday Sessions
       Session OM-TuP

Paper OM-TuP2
Adsorption of PTDCA on Si(100)

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: T. Soubiron, IEMN-CNRS, France
Authors: B. Grandidier, IEMN-CNRS, France
T. Soubiron, IEMN-CNRS, France
J.P. Nys, IEMN-CNRS, France
M. Dubois, IEMN-CNRS, France
C. Delerue, IEMN-CNRS, France
D. Stievenard, IEMN-CNRS, France
Correspondent: Click to Email
Submonolayer coverages of perylene-tetracarboxylic-dianhydride (PTCDA) molecules have been investigated with scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). At low coverage, comparisons between the STM images and calculations of the electronic structure of the molecule show that the molecule adsorbs mostly in a planar configuration with its axis parallel to the Si dimers. Different configurations are observed and associated with physisorbed and chemisorbed states of the adsorbates. At higher coverage, X-ray measurements indicate that only a fraction of the molecules are chemisorbed and that the bonding occurs through the dicarbonyl functional groups, preserving the pi-conjugation of the molecules. While PTCDA selectively reacts with the Si dimers, steric hindrance is found to be the major cause to hamper the formation of an ordered film.