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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 20: Organic Electronics and Photovoltaics II
CPP 20.8: Vortrag
Dienstag, 23. März 2010, 15:30–15:45, H37
Hole transport characteristics of pentacene studied with Green functions and real-time propagation — •Sebastian Radke1, Caroline Gollub1,2, Stanislav Avdoshenko1, Rafael Gutiérrez1, and Gianaurelio Cuniberti1 — 1Institute for Materials Science and Max Bergmann Center of Biomaterials, Dresden University of Technology — 2Max Planck Institute for the Physics of complex Systems, Dresden
For temperatures higher than 150 Kelvin the charge carrier mobility in organic semiconductors depends sensitively upon an interplay of band-like and hopping transport [1]. In this contribution, the hole transport characteristics of an organic semiconducting material are studied with two different theoretical methods and both approaches are compared. As a model system a pentacene structure is selected, which is well-characterized in the context of organic electronics. The first approach is based on a Green function formulation of the Holstein-Peierls model, accounting for local and non-local electron-phonon coupling and it addresses the transport problem in the energy space, so that fluctuations are taken into account only within a static picture. In the second approach, a real-time propagation of the charge carrier wave function is performed and this provides a deeper insight into the different time scales appearing in the problem. The Hamiltonian is formulated in the tight-binding representation, where the parametrization is evaluated for different levels of theory of the MD trajectories and of the electronic structure calculations.
[1] Y. C. Cheng, et al., J. Chem. Phys. 118, 3764 (2002).