Berlin 2015 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 56: Frontiers of electronic structure theory: Optical excitations
HL 56.1: Hauptvortrag
Mittwoch, 18. März 2015, 15:00–15:30, MA 004
Ultrafast coherent dynamics in photovoltaics — •Carlo Andrea Rozzi1, Sarah Maria Falke2, Daniele Brida3,4, Margherita Maiuri4, Michele Amato5, Ephraim Sommer2, Antonietta De Sio2, Angel Rubio6,7, Giulio Cerullo4, Elisa Molinari1,8, and Christoph Lienau2 — 1CNR-NANO, Modena, Italy — 2Carl von Ossietzky Universität, Oldenburg, Germany — 3University of Konstanz, Germany — 4CNR-IFN, Politecnico di Milano, Italy — 5Universitè Paris-Sud, Orsay, France — 6Universidad del País Vasco San Sebastián, Spain — 7Fritz-Haber-Institut, Berlin, Germany — 8Università di Modena e Reggio Emilia, Modena, Italy
The photoinduced charge-separation events occurring in photovoltaic systems 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 and algae. We have studied charge separation in reference systems for artificial photosynthesis and photovoltaics by combining TDDFT simulations of the quantum dynamics and high time resolution femtosecond spectroscopy. We provide evidence that the coherent coupling between electronic and nuclear degrees of freedom is of key importance in triggering charge delocalization and transfer both in covalently bonded molecules and in bulk heterojunctions[1]. We have exploited the results of our research to design, syntesize and characterize a novel molecular scaffold for photovoltaic applications.[2] [1] Falke S., et al., Science, 344, 1001 (2014) [2] Pittalis S., et al., Adv. Func. Mat. (2014)