AVS 46th International Symposium
    Organic Electronic Materials Topical Conference Monday Sessions
       Session OE-MoP

Paper OE-MoP4
Electronic Transport Properties of Self-assembled @pi@-conjugated Azomethine Oligomers

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: J.J.W.M. Rosink, Delft Institute of Microelectronics and Submicrontechnology, The Netherlands
Authors: J.J.W.M. Rosink, Delft Institute of Microelectronics and Submicrontechnology, The Netherlands
L.J. Geerligs, Delft Institute of Microelectronics and Submicrontechnology, The Netherlands
E. van der Drift, Delft Institute of Microelectronics and Submicrontechnology, The Netherlands
A.I. Onipko, Bogolyubov Institute for Theoretical Physics, Ukraine
Y. Klymenko, Space Research Institute, Ukraine
B.A.C. Rousseeuw, Delft Institute of Microelectronics and Submicrontechnology, The Netherlands
S. Radelaar, Netherlands Institute for Metals Research, The Netherlands
Correspondent: Click to Email
A novel technique for the controlled fabrication of @pi@-conjugated azomethine oligomers bonded to a substrate is presented. The resulting thin films can be used to study the intra-molecular electronic transport properties. Starting from a gold substrate, monolayers of small monomeric organic units are alternately deposited from solution. They order and connect to the previous layer by self-assembly. In each deposition step, chemisorption takes place at the interface between two monolayers through a condensation reaction. Oligomer chain growth has been analyzed by ellipsometry, gaschromatography, mass-spectrometry and x-ray photoelectron spectroscopy (XPS). Molecular mechanics calculations support the observation from ellipsometry and XPS that the azomethine molecules order roughly perpendicular to the gold surface. Based on scanning tunneling spectroscopy (STS) experiments an electronic model for these experiments is proposed. The Green function method is used to establish the relationship between the I-V curves registered in the STS measurements and the @pi@-electronic structure of the oligomers of type M@sub 1@-M@sub 2@-M@sub 1@... probed in the experiments. We have succesfully fitted I-V curves observed in STS of a single monomer film. Modelling of organic multilayers with a particular focus on the role of molecule-to-metal contact is in progress.