Efficient bulk heterojunction solar cells from regio-regular- poly(3,3‴-didodecyl quaterthiophene)/PC70BM blends

Blends of regio-regular poly(3,3‴-didodecyl quaterthiophene) (PQT-12) with (6,6)-phenyl-C70-butyric acid methyl ester (PC70BM) were investigated as active layers for application in organic photovoltaics (OPV). By optimizing the PQT-12:PC70BM composition ratio and annealing conditions, power conversion efficiencies (η) of 1.4% could be obtained. Effects of different preparation parameters on the incident photon conversion efficiency (IPCE), short-circuit (Jsc), fill factor (FF), open-circuit voltage (Voc) and η are discussed.