Naphthalenothiophene Imide-Based Polymer Donor for High-Performance Polymer Solar Cells
Haijun Ning, Gongya Zhang, Hui Chen, Zhuoran Wang, Shao‐Fei Ni, Fushen Lu, Fan Liu, Li Dang, Jiangang Liu, Feng He, Qinghe Wu
Abstract
Naphthalenothiophene imide (NTI), bearing six-membered imide and a five-membered aromatic ring, was synthesized by a one-step Suzuki reaction in high yield. NTI is an electron-deficient monomer that could effectively lower the HOMO energy level of the polymer. Thus, the NTI-based polymer PNTB1 has a low-lying HOMO energy level (−5.42 eV) without introducing any F or Cl group into the polymer backbone. By mixing with a nonfullerene electron acceptor Y6, solar cell devices exhibit power conversion efficiency as high as 15.18%. Because of the high efficiency of the NTI-based polymer and avoidance of multi-step synthesis of introducing other electron-accepting groups into the polymer chain, the electron-deficient NTI is a promising building unit for high-performance polymer donors.