In his dissertation, Koen investigated singlet fission, a process where two triplet states are created from a single singlet excitation, via a so-called triplet-pair state. This process takes place in specific organic semiconductors such as TIPS-tetracene, the material that is investigated in this work.
As shown in the thesis, the triplet-pair state can be probed optically at very low temperatures and at high magnetic fields. Combining both experimental work and computer simulations, Koen highlights the pivotal importance of the triplet-pair state for the spin-dynamics of the singlet fission process.
View the thesis