Molecular level control of donor/acceptor heterostructuresin organic photovoltaic devices

We have fabricated donor/acceptor-type organic photovoltaic devices based on copper phthalocyanine and Rose Bengal with varied number of donor/acceptor interfaces. Device architecture, namely, the number of such interfaces in the molecular scale, has been controlled via layer-by-layer electrostatic self-assembled film deposition technique. The interface area between donor and acceptor has been varied in order to optimize effective exciton separation and carrier transport. The number of donor/acceptor interfaces has opposite effects on exciton dissociation and charge transport in the devices. The results show that interface area has to be optimized to enhance the combined effect of exciton dissociation and carrier transport in organic photovoltaic devices.