Oligoselenophene Derivatives Functionalized with a Diketopyrrolopyrrole Core for Molecular Bulk Heterojunction Solar Cells

Solution-processable oligoselenophenes functionalized with diketopyrrolopyrfole cores have! been synthesized for use as the donor material in bulk heterojunction solar cells. The optical " absorption of these materials extends to the edge of the visible spectrum. Power conversion efficiencies of 1.53 +/- 0.04% for DPPS and 0.84 +/- 0.04% for DPPDS were obtained under simulated 100 mW/cm(2) AM 1.5G irradiation for devices when PC61BM was used as an acceptor. DPPS showed hole mobilities of 4 x 10(-5) cm(2)/(V s) and a peak erternal quantum efficiency (EQE) of 25%, while DPPDS showed hole mobilities of 2 x 10(-5) cm(2)/(V s) and a peak EQE of 19%. To the best of our knowledge, these are the first oligoselenophenes that have been reported in molecular bulk heterojunction solar cells and this study could serve as a springboard for the design and optimization of high-performance selenophene-containing photovoltaics.