Hyperpolarised electron spins as a sensitive probe for investigating structure–function relationship in organic energy materials

Energy conversion and storage is of paramount importance, and organic functional materials are increasingly being used for this purpose. Hyperpolarised electron spins as created, e.g., by light excitation act as sensitive probe of their environment. This allows to investigate the structure–function relationship of these materials by using time-resolved electron paramagnetic resonance (TREPR) spectroscopy. Insights range from morphology and details of the aggregation behaviour in both, film and solution to triplet routes to the electronic structure of these materials far beyond exciton delocalisation. Here, we focus particularly on the effects of conjugation break and systematic backbone variation on exciton delocalisation as well as solvent and cooling rate on aggregate formation. TREPR spectroscopy provides insight into these effects with molecular resolution that is not available by and complementary to other methods.