Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 30: P2: Organic Electronics and Photovoltaics
CPP 30.3: Poster
Dienstag, 17. März 2015, 14:00–16:00, Poster B
Interplay of Environmental and Molecular Factors in Backbone Order of a Semiconducting Polymer: A DFT Study of Polyfluorenes — •Elizabeth Lupton1, Feng Liu2, and Bernhard Dick1 — 1Institute for Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany — 2Department of Materials Science and Engineering, University of Utah, Salt Lake City, UT 84112, USA
The environmental and molecular parameters which determine the nature of chromophores in polymeric systems are identified through systematic studies of molecules with well defined structures. Polyfluorenes exhibit both disordered and ordered phases which depend on the degree of planarity of the conjugated polymer backbone and can be distinguished spectroscopically. We examine the intrinsic and extrinsic factors that determine the ordering of the backbone using DFT and TDDFT calculations. We determine that a stable ordered phase with a specific torsional angle between repeat units exists which planarizes on exitation, and that specific deviations from the ordering, such as rotations which cause deviations from backbone linearity, do not affect the molecules' ability to planarize. The results demonstrate the complicated interplay between external confinement, intermolecular properties and photoexcitation in determining the structure and photophysics of organic semiconducting polymers.