Hot charge-transfer excitons set the time limit for charge separation at donor/acceptor interfaces in organic photovoltaics

Photocurrent generation in organic solar cells relies on the dissociation of excitons into free electrons and holes at donor/acceptor heterointerfaces. Femtosecond spectroscopy and non-adiabatic simulations on the phthalocyanine–fullerene model system now reveal the relaxation dynamics of hot charge-transfer excitons in this process.