| People involved: | Sumera Tubasum, Tõnu Pullerits |
| Former members: | Mats Dahlbom, Tomáš Polívka, Niklas Christensson, Tommy Garting |
This project is related to the following Fields, Subjects and Techniques:
| Fields: | |
| Subjects: | Photosynthesis |
| Techniques: | Fluorescence line narrowing, Pump-probe spectroscopy |
At low temperatures we have observed strongly red-shifted emission in transient-absorption measurements of light-harvesting complexes indicating formation of excitonic polarons - collective excitations accompanied with a significant deformation of environment which leads to exciton self-trapping. During that process the extent of coherence in the system shrinks from about 5 nm to 2-3 nm. We have developed a model capable to describe simultaneously dynamic processes like exciton relaxation, localization, polaron formation and diffusion of self-trapped excitons. Recently we have carried out fluorescence line narrowing spectroscopy measurements which were analyzed in terms of polaron formation. We relate polarons to the electronic states with strong charge-transfer character.