High-Performance All-Polymer Solar Cells Enabled by an n-Type Polymer Based on a Fluorinated Imide-Functionalized Arene

Huiliang Sun, Yumin Tang, Chang Woo Koh, Shaohua Ling, Ruizhi Wang, Kun Yang, Jianwei Yu, Yongqiang Shi, Yingfeng Wang, Han Young Woo, Xugang Guo

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41 Citations (Scopus)

Abstract

A novel imide-functionalized arene, di(fluorothienyl)thienothiophene diimide (f-FBTI2), featuring a fused backbone functionalized with electron-withdrawing F atoms, is designed, and the synthetic challenges associated with highly electron-deficient fluorinated imide are overcome. The incorporation of f-FBTI2 into polymer affords a high-performance n-type semiconductor f-FBTI2-T, which shows a reduced bandgap and lower-lying lowest unoccupied molecular orbital (LUMO) energy level than the polymer analog without F or with F-functionalization on the donor moiety. These optoelectronic properties reflect the distinctive advantages of fluorination of electron-deficient acceptors, yielding “stronger acceptors,” which are desirable for n-type polymers. When used as a polymer acceptor in all-polymer solar cells, an excellent power conversion efficiency of 8.1% is achieved without any solvent additive or thermal treatment, which is the highest value reported for all-polymer solar cells except well-studied naphthalene diimide and perylene diimide-based n-type polymers. In addition, the solar cells show an energy loss of 0.53 eV, the smallest value reported to date for all-polymer solar cells with efficiency > 8%. These results demonstrate that fluorination of imide-functionalized arenes offers an effective approach for developing new electron-deficient building blocks with improved optoelectronic properties, and the emergence of f-FBTI2 will change the scenario in terms of developing n-type polymers for high-performance all-polymer solar cells.

Original languageEnglish
Article number1807220
JournalAdvanced Materials
Volume31
Issue number15
DOIs
Publication statusPublished - 2019 Apr 12

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Keywords

  • all-polymer solar cells
  • fluorination
  • imide-functionalized arene
  • n-type polymer
  • organic electronics

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Sun, H., Tang, Y., Koh, C. W., Ling, S., Wang, R., Yang, K., Yu, J., Shi, Y., Wang, Y., Woo, H. Y., & Guo, X. (2019). High-Performance All-Polymer Solar Cells Enabled by an n-Type Polymer Based on a Fluorinated Imide-Functionalized Arene. Advanced Materials, 31(15), [1807220]. https://doi.org/10.1002/adma.201807220