| People involved: | Eva Åkesson, Tõnu Pullerits, Torbjörn Pascher, Villy Sundström, Arkady Yartsev |
| Former members: | Jane Larsen, Johan Andersson, Tomáš Polívka |
This project is related to the following Fields, Subjects and Techniques:
Natural photosynthesis utilizes two coupled pigment systems, a light-harvesting antenna and a photochemical reaction center, for efficient conversion of light-energy into stabilized charges that is used to drive the conversion of solar energy into chemically stable high energy products. The need for a coupled antenna-reaction center system is easily realized by considering the fact that the photochemical reaction in photosynthesis, splitting of water and formation of molecular oxygen, requires that four photochemical cycles of the reaction center occur in quite short time (typically a millisecond). On this time scale all charge- separated states undergo recombination reactions to the ground state, which causes the loss of the acquired photon energy. Without an antenna system coupled to the reaction center that can collect and deliver sufficient number of photons in the required short time before charge recombination occurs, the conversion efficiency of any photocatalytic system remains very low at the ambient light intensities (photon fluxes) delivered by the sun. Thus, the requirement of an antenna coupled to a photochemical reaction center can be expected to be a necessary feature for efficient photocatalytic operation at ambient solar light intensities in any artificial solar energy conversion system.
