Empirical Model of the Charge Carriers’ Photogeneration in Organic Solar Cells

A model of the photocurrent generation of charge carriers in blends of donor (D) and acceptor (A) materials structured on the nanoscale is considered. The absorption of a quantum of light in one of these materials creates a molecular exciton, which can reach the interface between the D and A phases and form an interfacial charge transfer (CT) exciton on this interface, which dissociates into an electron-hole pair. The probabilities of the dissociation of CT excitons into free current carriers are calculated as a function of the electric field and the thermalization length of the electron-hole pair.