Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 86: Organic electronics and photovoltaics V (CPP, jointly with HL, O)

HL 86.2: Vortrag

Donnerstag, 14. März 2013, 15:30–15:45, H34

Simulations of Electron Transfer in a Fullerene Hexa-Pyropheophorbide-a Complex — •Thomas Plehn, Jörg Megow, and Volkhard May — Humboldt-Universität zu Berlin, Germany

Electron transfer (ET) is studied between electronically excited chromophores and a C60 fullerene forming a highly flexible complex, which is dissolved in a solvent. Such investigations are of particular interest with regard to future artificial photosynthetic reaction centers and respective applications in future components of photovoltaic devices. The whole discussion is based on extended MD-simulations. To obtain reliable ET results three differently advanced theories are used. The first treatment uses the classical Marcus theory. Respective Marcus parameters are obtained from literature [1]. A generalized ansatz can be derived by the Landau-Zener theory [2]. Secondly, a semi-classical surface-hopping method [3] is chosen. For this approach the conformation-dependent free-energy surfaces and Marcus parameters are calculated directly from the MD-trajectory. The third approach uses the dispersed-polaron/spin-boson model [3]. This method enables the approximation of a quantum-mechanical harmonic oscillator bath and thus the treatment of nuclear tunneling. A comparative discussion of the outcome of these three methods also in relation to experiment [1] is given finally.

[1] Regehly M. et al., J. Phys. Chem. B 2007, 111, 998

[2] Hilczer M. et al., J. Photochem. Photobiol. A 2003, 158, 83

[3] Warshel A. et al., Q. Rev. Biophys. 2001, 34, 4, 563