Deciphering the Role of Chalcogen-Containing Heterocycles in Nonfullerene Acceptors for Organic Solar Cells
Gaoda Chai, Jianquan Zhang, Mingao Pan, Zhen Wang, Jianwei Yu, Jiaen Liang, Han Yu, Yuzhong Chen, Ao Shang, Xiyuan Liu, Fujin Bai, Ruijie Ma, Yuan Chang, Siwei Luo, An‐Ping Zeng, Hang Zhou, Kai Chen, Feng Gao, Harald Ade, He Yan
Abstract
The field of organic solar cells has experienced paradigm-shifting changes in recent years because of the emergence of nonfullerene acceptors (NFAs). It is critically important to gain more insight into the structure–property relationship of the emerging A′-DAD-A′-type NFAs. In this Letter, a family of NFAs named BPF-4F, BPT-4F, and BPS-4F incorporating various chalcogen-containing heterocycles, i.e., furan, thiophene, and selenophene, respectively, was designed and synthesized. These NFAs exhibited dramatic differences in their photovoltaic performances with device efficiencies of 16.8% achieved by the thiophene-based cells, which was much higher than the furan-based ones (12.6%). In addition, the selenophene-based NFA showed a red-shifted absorption relative to the furan- and thiophene-based ones and obtained a decent efficiency of 16.3% owing to an improved JSC. The reasons why these NFAs performed differently are systematically studied by comparing their optoelectronic properties and film morphology, which provides new understandings of the molecular design of high-performance NFAs.