Synthesis and photovoltaic properties of three different types of terpolymersElectronic supplementary information (ESI) available: Synthesis and characterization of intermediates, SCLC measurements, GIWAXS line-cut profiles and packing parameters. See DOI: 10.1039/c6qm00267f

• Main Authors: Uddin, Mohammad Afsar, An, Na Gyeong, Li, Yuxiang, Song, Seyeong, Ryu, Hwasook, Kim, Jin Young, Woo, Han Young
• Format: Journal Article
• Language: English
• Published: 01.06.2017
• ISSN: 2052-1537
• DOI: 10.1039/c6qm00267f

Three types of photoactive terpolymers (Random, Regular and Block) were synthesized by incorporating two electron-deficient moieties and one electron-rich moiety based on two parent donor polymers, poly[(2,5-bis(2-decyltetradecyloxy)phenylene)- alt -(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[ c ][1,2,5]thiadiazole)] (PPDT2FBT DT ) and poly[(2,5-bis(2-decyltetradecyloxy)phenylene)- alt -(5,6-dicyano-4,7-di(thiophen-2-yl)benzo[ c ][1,2,5]thiadiazole)] (PPDT2CNBT). All three terpolymers showed broad light absorption in the range of 300-850 nm covering the absorption of two parent polymers. Their optical, electrochemical, morphological and photovoltaic properties were compared and investigated in detail. Power conversion efficiencies (PCEs) of 5.63, 4.45 and 3.13% were obtained for PPDT2FBT DT - random -PPDT2CNBT, PPDT2FBT DT - regular -PPDT2CNBT and PPDT2FBT DT - block -PPDT2CNBT based photovoltaic devices, respectively. Through intensive investigation on charge carrier mobility, photocurrent and light intensity dependence of J SC , the random structure was proved to be the most effective molecular design in this series of terpolymers, showing weaker charge recombination and enhanced charge transport/extraction with well-distributed blend morphology. The fine modulation of different arrangements and compositions of the three monomers in a main chain is crucial for optimizing the terpolymeric structures as efficient photoactive materials. A series of terpolymers (Random, Regular and Block) based on dithienylphenylene, difluorobenzothiadiazole and dicyanobenzothiadiazole moieties were synthesized, and their optical, electrochemical, morphological, electrical and photovoltaic properties were studied.