Photoluminescence studies on the supramolecular interactions between a pyrollidinofullerene and zinc-phthalocyanine used in organic solar cells

We present a study of supramolecular interactions between a highly soluble pyrollidinofullerene bearing three chelating pyridyl groups (PyF) and zinc-phthalocyanine (ZnPc). Photoluminesccnce quenching shows a non-diffusive concentration dependency, which can be explained by the formation of a non-covalently bonded supramolecular dyad. A further indication for such a complexation is observed by a significantly increased solubility of ZnPc in CH2Cl2 upon addition of PyF. Solar cells fabricated from a thin evaporated layer of ZnPc and a spincoated layer of PyF show short-circuit current densities of approximately 4 mA/cm(2) with open circuit voltages around 400 mV under 100 mW/cm(2) simulated AM1.5 illumination.