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SYOE: Symposium Organic Thin Film Electronics: From Molecular Contacts to Devices
SYOE 8: Poster Session SYOE
SYOE 8.106: Poster
Dienstag, 27. März 2007, 18:00–20:00, Poster B
Conformational disorder of conjugated polymers — Sebastian Westenhoff2, •Wichard Beenken1, Arkady Yartsev3, and Neil Greenham2 — 1Technische Universität Ilmenau, FG Theoretische Physik I, Postfach 100565, 98684 Ilmenau, Deutschland — 2Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CH3 0HE, United Kingdom — 3Lunds Universitet, Kemisk Fysik, Box 124, 22100 Lund, Schweden
Conformational disorder of conjugated polymers is an important issue to be understood and quantified. In this paper we present a new method to assess the chain conformation of conjugated polymers based on measurements of intrachain energy transfer. The chain conformation is modeled on the basis of monomer-monomer interactions, such as torsion, bending, and stretching of the connecting bond. The latter two potentials are assumed to be harmonic, while the torsional potential was calculated by density functional theory using B3-LYP functional with the SVP basis set. The energy transfer dynamics of excitons on these chains are quantitatively simulated using Förster-type line-dipole energy transfer. This allows us to compare the simulated ground state conformation of single polymer chains to ultrafast depolarization experiments of poly [3-(2,5-dioctylphenyl)thiophene] in solution. We identify torsional rotation as the main contributor to conformational disorder and find that this disorder is mainly controlled by the energy difference between syn and anti bonds. [J. Chem. Phys. 125, 154903 (2006)]