Nonfused Nonfullerene Acceptors with an A–D–A′–D–A Framework and a Benzothiadiazole Core for High-Performance Organic Solar Cells

• Published in: ACS applied materials & interfaces 2020-04, Vol.12 (14), p.16531-16540
• Main Authors: Pang, Shuting, Zhou, Xia, Zhang, Song, Tang, Haoran, Dhakal, Sujata, Gu, Xiaodan, Duan, Chunhui, Huang, Fei, Cao, Yong
• Format: Article
• Language: English
• Subjects: MATERIALS SCIENCE
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.0c01850

Nonfullerene acceptors (NFAs) have contributed significantly to the progress of organic solar cells (OSCs). However, most NFAs feature a large fused-ring backbone, which usually requires a tedious multiple-step synthesis, and are not applicable to commercial applications. An alternative strategy is to develop nonfused NFAs, which possess synthetic simplicity and facile tunability in optoelectronic properties and solid-state microstructures. In this work, we report two nonfused NFAs, BTCIC and BTCIC-4Cl, based on an A–D–A′–D–A architecture, which possess the same electron-deficient benzothiadiazole central core but different electron-withdrawing terminal groups. The optical properties, energy levels, and molecular crystallinities were finely tuned by changing the terminal groups. Moreover, a decent power conversion efficiency of 9.3 and 10.5% has been achieved by BTCIC and BTCIC-4Cl, respectively, by blending them with an appropriate polymer donor. These results demonstrate the potential of A–D–A′–D–A type nonfused NFAs for high-performance OSCs. Further development of nonfused NFAs will be very fruitful by employing appropriate building blocks and via side-chain optimizations.