Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 10: POSTERS New Materials, Organic Semiconductors
CPP 10.8: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
Atomistic force field and electronic properties of carbazole: melt and macrocyle — •Thorsten Vehoff1, James Kirkpatrick2, Kurt Kremer1, and Denis Andrienko1 — 1Max-Planck-Institut fùr Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany — 2Department of Physics, Imperial College London, Prince Consort Road, London SW7 2B W, United Kingdom
Processable polymers with a conjugated backbone, e.g. carbazole, are interesting for use as hole conducting materials. Hole transport characteristics strongly depend on the local arrangement of molecules; for this reason, to obtain an efficient device, it is necessary to control the morphology of the material: very often, small changes of the structure (e.g. longer alkane side chains) or processing conditions (annealing regime, choice of solvents) result in a significant change of the morphology and, hence, charge carrier mobility.
In this contribution, we study the columnar mesophase of a carbazole macrocycle1. First an atomistic force field is developed for carbazole furnished with alkyne side chains as well as carbazole dimers and then tested on a melt of carbazole oligomers by evaluating properties such as the density and diffusion coefficient and comparing with experimental results. The mobility of charge carriers along the columns is calculated by first computing charge hopping rates between carbazole monomers and macrocycles according to Marcus theory and then solving the master equation for charge dynamics.