Abstract
Solar cells based on organic materials are an emerging technology with a wide range of possible applications. The distribution of charge carriers in the most efficient devices, based on a bulk-heterojunction active layer structure, is hard to investigate by experiments. Modeling these cells by a kinetic Monte Carlo algorithms allows to consider a realistic morphology for the active layer and to investigate the charge densities along the interfaces between the two heterojunction materials. A major influence on the charge distribution can be attributed to the dielectric permittivity of the organic materials.