Berlin 2012 – wissenschaftliches Programm
HL 79.1: Vortrag
Donnerstag, 29. März 2012, 10:30–10:45, EW 201
First principles study of photoinduced charge separation in an artificial light harvesting complex — •Carlo Andrea Rozzi1, Sarah Maria Falke2, Nicola Spallanzani1, Angel Rubio3, Elisa Molinari1, Daniele Brida4, Margherita Maiuri4, Giulio Cerullo4, Heiko Schramm2, Jens Christoffers2, and Christoph Lienau2 — 1CNR - Istituto Nanoscienze, Modena, Italy — 2Carl von Ossietzky Universität, OIdenburg, Germany — 3Fritz-Haber-Institut der MPG, Berlin, Germany — 4Politecnico di Milano, Italy
Nature has developed sophisticated and highly efficient molecular architectures to convert sunlight energy into chemical energy. It is known that the primary steps, specifically both energy and charge transfer, occur on extremely fast time scales. These processes have traditionally been interpreted in terms of the incoherent kinetics of optical excitations and of charge hopping, but recently signatures of quantum coherence were observed in energy transfer in photosynthetic bacteria. We have studied a carotene-porphyrin-fullerene triad, which is a prototypical artificial reaction center, by Time-dependent Density Functional Theory simulations of the quantum dynamics. In combination with high time resolution femtosecond spectroscopy our results provide clear evidence that the driving mechanism of the charge separation process is a quantum correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds, thus establishing the role of quantum coherence in artificial light harvesting.