Light-induced electron spin resonance as a probe for charge separation and recombination in hybrid donor:acceptor systems

- L-ESR as a probe for charge separation in donor:acceptor blends is reviewed.
- L-ESR as a probe for charge carrier recombination is reviewed.
- Organic and hybrid donor:acceptor systems are compared.

Donor:acceptor systems are the core of many concepts for photovoltaic devices, because they provide a mean to separate photo-generated electron-hole pairs into extractable charge carriers. In organic photovoltaics, donor:acceptor systems consist of two different organic semiconductors. Alternatively, inorganic semiconductor nanocrystals are also suitable materials. Their use in combination with an organic material gives rise to hybrid systems. Charge separation being a key step in the energy conversion process, suitable methods are required to study this physical process. The present review article provides an overview on the use of light-induced electron spin resonance as a powerful method to investigate charge separation in donor:acceptor blends. Thereby, organic and hybrid material systems are compared. Furthermore, detailed investigations of recombination processes are considered as well.

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