Physics colloquium by Rienk van Grondelle

Speaker: Rienk van Grondelle (University of Amsterdam and University of Pretoria)

Abstract:

Photosynthesis converts the energy of solar photons into the energy of charge
separated states. To do so photosynthesis employs pigments (chlorophylls,
carotenoids) bound to proteins. Light harvesting proteins (LHCs) absorb the light and
transfer the energy on an ultrafast (fs-ps) timescale to reaction centres (RCs) where
the electronic excitation energy is converted into a stable trans-membrane charge
separation. Both in LHCs and in RCs the delocalized electronic states (Frenkel
excitons) are mixed with charge transfer (CT) states as reflected by their strong
electro-optical response. Using 2D-electronic spectroscopy (2DES) we detected the
weakly allowed CT-exciton states in RCs and LHCs. In this talk I will review these
experiments plus modelling and fantasize about the possible functional implications.