Synthesis of donor–acceptor poly(perylene diimide-altoligothiophene) copolymers as n-type materials for polymeric solar cells

Donor–acceptor alternated copolymers based on perylene diimide units linked in bay positions with oligothiophene units were prepared and used as acceptor material in polymeric solar cells. The copolymers have exhibited ambipolar electrochemical properties, high electronic affinities and wide electronic absorption in the visible spectrum. The spectroscopical characterization of the copolymer blends with poly-3-hexylthiophene showed evidences indicative of a charge transfer from the perylene-based copolymers to the polythiophene. All-polymeric solar cells were prepared with the blends and the photovoltaic characterization of these devices showed conversion efficiencies of 0.8% and 0.4%. The results demonstrate the potentialities of perylene-based copolymers as processable photoactive acceptor in organic solar cells.