  In this article a concept is introduced, which allows for reduced Coulomb
interaction in organic solar cells and as such for enhanced power conversion
efficiencies. The concept is based on the introduction of electrically
insulating, nanostructured high-k materials into the organic matrix, which do
not contribute to the charge transport, however, effectively enhance the
permittivity of the organic active layer and thereby reduce the Coulomb
interaction. Using an analytical model it is demonstrated that even at a
distance of 20 nm to the organic / inorganic interface of the nanostructure,
the Coulomb interaction can be reduced by more than 15 %. The concept is
implemented using P3HT:PCBM solar cells with integrated high-k nanoparticles
(strontium titanate). It could be demonstrated that in comparison to a
reference cell without integrated nanoparticles, the power conversion
efficiencies could be improved by ~20 %.
