Theoretical study of exciton dissociation through hot states at donor–acceptor interface in organic photocell
We theoretically study the dissociation of geminate electron–hole pairs (i.e., excitons) through vibrational hot states at the donor–acceptor interface of organic photocells. To conduct this, we modify the formalism of Rubel et al. [Phys. Rev. Lett., 2008, 100, 196602], and use the theoretical concepts of Arkhipov et al. [Phys. Rev. Lett., 1999, 82, 1321] and Knights et al. [J. Phys. Chem. Sol., 1974, 35, 543] to consider vibrational hot states. The effects of band-offset energy and the dissipation of excess energy are discussed on the basis of calculations of the escape probability for hot electrons. Furthermore, we show that vibrational hot state and delocalization of excitons lead to an increased probability to separate geminate electron–hole pairs.