Synthesis and Photovoltaic Characterization of Dithieno[3,2-b:2′,3′-d]thiophene-Derived Narrow-Bandgap Polymers

Authors

  • Enwei Zhu,

    1. Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing, P. R. China
    Search for more papers by this author
  • Bin Ni,

    1. Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing, P. R. China
    Search for more papers by this author
  • Baofeng Zhao,

    1. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, P. R. China
    Search for more papers by this author
  • Jiefeng Hai,

    1. Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing, P. R. China
    Search for more papers by this author
  • Linyi Bian,

    1. Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing, P. R. China
    Search for more papers by this author
  • Hongbin Wu,

    1. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, P. R. China
    Search for more papers by this author
  • Weihua Tang

    Corresponding author
    1. Key Laboratory of Soft Chemistry and Functional Materials, Ministry of Education, Nanjing University of Science and Technology, Nanjing, P. R. China
    Search for more papers by this author

Abstract

image
Three novel dithieno[3,2-b:2′,3′-d]thiophene-based low-bandgap polymers are synthesized by a Suzuki–Miyaura coupling reaction or by direct arylation polycondensation. The polymers present a high molecular weight (26–32 kDa) and narrow polydiversity (1.3–1.7). With a highest occupied molecular orbital (HOMO) energy level around −5.20 eV, these polymers exhibit a narrow bandgap of 1.75–1.87 eV. All the polymers display strong absorption in the range of 350–700 nm. Bulk-heterojunction (BHJ) solar cells are further fabricated by blending the as-prepared polymer with (6,6)-phenyl-C61-butyric acid methyl ester (PC61BM) at different weight ratios. The best devices contribute a power conversion efficiency (PCE) of 0.73% under AM 1.5 (100 mW cm−2).

Ancillary