Abstract The present article mainly focuses on the synthesis of copolymers alternating thienothiophene, diketopyrrolopyrrole based units with thiophene spacers were designed, synthesized and characterized. The synthesized polymers were characterized for thermal stability, structural and its photovoltaics properties. All the synthesized polymers showed good solution formability, exhibits high thermal stability up to 200 °C, and ~1.8eV optical band gap. And also, the polymers synthesized using dithiophene spacer exhibit low energy band gap and hence broad optical absorption range. These polymers were used as a donors and PC61BM acceptor to fabricate the. Devices were fabricated for various solution concentration and ratios of donor: acceptor to attain the maximum achievable efficiency. For the preliminary optimized device condition the maximum obtained efficiencies is 1.06%, JSC is 66.3 Am−2, VOC is 0.65 V and fill factor is 23.7%.

中文翻译：

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低带隙噻吩并噻吩-二酮吡咯并吡咯共聚物，以 V2O5 作为空穴传输层用于光伏应用

摘要 本文主要研究了噻吩并噻吩交替共聚物的合成，设计、合成并表征了具有噻吩间隔基的二酮吡咯并吡咯单元。合成的聚合物具有热稳定性、结构和光伏特性。所有合成的聚合物都显示出良好的溶液成型性，在高达 200°C 时表现出高热稳定性和~1.8eV 的光学带隙。而且，使用二噻吩间隔物合成的聚合物表现出低能带隙，因此具有宽的光吸收范围。这些聚合物被用作供体和 PC61BM 受体来制造。为各种溶液浓度和供体：受体比例制造器件，以获得最大可实现的效率。