SEPARAZIONE DI CARICA IN MISCELE DI MATERIALI ORGANICI: VALE LA LEGGE DI COULOMB?

After a brief introduction to organic photovoltaic materials, I discuss the problem of charge separation in these systems. In the best devices, the excitations produced by absorption of a photon can be converted into positive and negative charge carriers (holes and electrons, respectively) with near-100% efficiency. Such efficiencies are apparently at odds with Coulomb’s law, which would lead to change recombination due to their mutual electrostatic attraction. A theoretical model developed within my group overcomes this apparent contradiction, by taking into account quantum mechanical effects such as the delocalization of the charge carriers.