Photons and Electrons on the Move

The conversion of sunlight photons to electrons is the essence of the natural photosynthesis that powers life. Dedicated antennas funnel the suns energy towards reaction centres. Amazingly, nature reaches almost perfect photon-to-electron conversion efficiency, while it regulates down at high light level for protection and survival.How does nature dynamically re-organize the membrane architecture, its packing, order, diffusion, on light stress? Which pathways are taken to charge separation? What is the role of fluctuations, coherences, color and vibrations?My group recently succeeded in first detection of the fs spectral progression of a single exciton, the nanoscale tracking of electron transport and reveal energy disorder of a single photosynthetic complex. These pioneering results, together with our expertise in fs pulse control and nanoimaging, set the grounds to now address photosynthetic light-to-charge transfer in real nanospace and ultrafast. Specific objectives are:Energy transport on the nanoscale: tracking spatiotemporal membrane transport by super-resolved transient optical microscopy and nanophotonic light localization: to reveal disorder and quantify diffusion.Light to charge: photo-current detection of the energy flow: by ultrafast photo-thermoelectric graphene and photo-electrochemical detection I will probe charge separation of the reaction center directly, quantify rate and efficiency.Multidimensional spectra on the nanoscale: by collinear 2D spectroscopic imaging with photocurrent and fluorescence detection, I will map the development of the energy landscape, at special membrane spots, ultimately on a single complex.Functional imaging: visualize the dynamic light-response of the membrane architecture, the changes in packing density, (dis)order, diffusion and pathways to charge separation.The novel tool-set of FastTrack and the insights on natures energy strategies are directly relevant for artificial photosynthesis and solar technology.