Thin organic films – growth and structural properties

description:
The optical and the electrical properties of thin organic films are highly aniostropic, Therefore, the crystalline properties like polymorphism, texture within these films, size of the crystallites, but also the film morphology are extremely important parameters for future application of these films in industrial products.

Left: Indexed x-ray diffraction pole figures of epitaxially grown sexiphenyl on mica(001)
Right: The six epitaxial relationships of sexiphenyl crystallites on a single crystalline mica(001) surface (from H. Plank, R. Resel, et al., Phys. Rev. B , vol. 64, p.235423 (2001))

special equipment:
X-ray powder diffractometer: Siemens D501
X-ray texture goniometer: Philips X'Pert System mit ATC3 Cradle

software development :
Stereopole - a software for the analysis of x-ray diffraction pole figures with IDL was developed, and can be >>downloaded<< free of charge.
(see: I. Salzmann and R. Resel, Journal of Applied Crystallography, 2004, submitted)

co-workers:
Martin Oehzelt, PhD student
Ondrej Lengyel, PhD student
Thomas Haber, diploma student
Ingo Salzmann, diploma thesis, January 2003
Harald Plank, diploma thesis, March 2002
Kurt Erlacher, diploma thesis, August 1999
Roland Resel, project director

co-operations:
Jozef Keckes, Erich Schmid Institut Leoben
Andrei Andreev, H. Sitter, N. S. Sariciftci, Universität Linz
Annette Thierry, Bernard. Lotz, Institut Charles Sadron, Strassburg
Christian Teichert, University Leoben
Michael Ramsey, University Graz
Adolf Winkler, Graz University of Technology
Detlef Smilgies, CHESS, Cornell University
Horst –Günther Rubahn, Odense University

financial support:
Austrian Science Foundation, project no.: P15626-TPH (10/2002-9/2004)
Action Austria – Slovakia, Austrian Academic Exchange, project no.: 22s29
(5/98 – 12/98)

important publications:
R. Resel, N. Koch, F. Meghdadi, G. Leising, W. Unzog, K. Reichmann,
Growth and preferred crystallographic orientation of hexaphenyl thin films
Thin Solid Films, vol.305, no.1-2, p.232-42 (1997)

H. -J. Brandt, R. Resel, J. Keckes, B. Koppelhuber-Bitschnau, N. Koch, G. Leising,
Determination of crystallite size and lattice strain in hexaphenyl thin films by line profile analysis
Mat. Res. Soc. Symp. Proc., vol.561, p.161-6, (1999)
(Materials Research Society - Spring Meeting, Symposium F: Organic Nonlinear Optical Materials and Devices, San Francisco, California, USA, 5-9 April 1999)

K. Erlacher, R. Resel, S. Hampel, T. Kuhlmann, K. Lischka, B. Müller, A. Thierry, B. Lotz, G. Leising,
Epitaxial growth of para-hexaphenyl on GaAs(001)-2x4
Surface Science, vol.437, p.191-7 (1999)

R. Resel, K. Erlacher, B. Müller, A. Thierry, B. Lotz, T. Kuhlmann, K. Lischka, G. Leising,
Molecular Beam Epitaxy of para-hexaphenyl on GaAs(111)
Surf. Interf. Analy., vol.30, no.1, p.518-21 (2000)
(7th European Conference on Analysis of Surfaces and Interfaces, Sevila, Spain, 4-8 October 1999)

R. Resel, M. Ottmar, M. Hanack, J. Keckes, G. Leising
Preferred orientation of copper phthalocyanine thin films evaporated on amorphous substrates
J. Mater. Res., vol.15, no.4, p. 934-9 (2000)

R. Resel, N. Koch, F. Meghdadi, G. Leising, L. Athouel, G. Froyer, F. Hofer,
A polymorph crystal structure of hexaphenyl observed in thin films
Cryst. Res. Technol., vol.36, no.1, p.47-54 (2001)

H. Plank, R. Resel, S. Purger, J. Keckes, A. Thierry, B. Lotz, A. Andreev, N. S. Sariciftci, H. Sitter
Heteroepitaxial growth of self-assembled highly ordered para-sexiphenyl films: a
crystallographic study
Phys. Rev. B, vol.64, p. 235423-1 … - 5 (2001)

H. Plank, R. Resel, N. S. Sariciftci, A. Andreev, H. Sitter, G. Hlawacek, C. Teichert, A. Thierry, B. Lotz,
Molecular alignments in epitaxial grown sexiphenyl films on mica(001)
Thin Solid Films, (2003) submitted

Left: Transmission Electron Microscopy (TEM) on a sexiphenyl thin film grown on a mica(001) surface, sexiphenyl grows in a needle like morphology. Right: Selected area transmission electron diffraction (taken form the area of the red circle of the TEM pattern) above; and the indexed diffraction pattern below (from H. Plank, R. Resel, Thin Solid Films 2003).