Synthesis and Photovoltaic Properties of Conjugated Copolymers with Benzo[1,2-b:4,5-b′]dithiophene and Bis(thiophene)phthalimide Units

Authors

  • Guobing Zhang,

    1. Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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  • Yingying Fu,

    1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, China
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  • Qing Zhang,

    Corresponding author
    1. Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
    • Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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  • Zhiyuan Xie

    Corresponding author
    1. State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, China
    • State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, China.
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Abstract

Two new donor/acceptor copolymers PBDTPhBT1 and PBDTPhBT2 with alternating benzodithiophene (BDT) and bisthiophene-phthalimide (PhBT) units were synthesized by Stille coupling reaction. The copolymers showed identical optical bandgaps of 1.98 eV. The HOMO energy levels are −5.35 and −5.32 eV for PBDTPhBT1 and PBDTPhBT2, respectively. The bulk heterojunction solar cell devices based on these copolymers as donors and PC71BM as acceptor displayed high open-circuit voltages of 0.90–0.93 V and achieved power conversion efficiency of 1.54% under the illumination of AM 1.5, 100 mW · cm−2.

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