1. Geometry design of tethered small-molecule acceptor enables highly stable and efficient polymer solar cells
- Author
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Yang Bai, Ze Zhang, Qiuju Zhou, Hua Geng, Qi Chen, Seoyoung Kim, Rui Zhang, Cen Zhang, Bowen Chang, Shangyu Li, Hongyuan Fu, Lingwei Xue, Haiqiao Wang, Wenbin Li, Weihua Chen, Mengyuan Gao, Long Ye, Yuanyuan Zhou, Yanni Ouyang, Chunfeng Zhang, Feng Gao, Changduk Yang, Yongfang Li, and Zhi-Guo Zhang
- Subjects
Science - Abstract
Abstract With the power conversion efficiency of binary polymer solar cells dramatically improved, the thermal stability of the small-molecule acceptors raised the main concerns on the device operating stability. Here, to address this issue, thiophene-dicarboxylate spacer tethered small-molecule acceptors are designed, and their molecular geometries are further regulated via the thiophene-core isomerism engineering, affording dimeric TDY-α with a 2, 5-substitution and TDY-β with 3, 4-substitution on the core. It shows that TDY-α processes a higher glass transition temperature, better crystallinity relative to its individual small-molecule acceptor segment and isomeric counterpart of TDY-β, and a more stable morphology with the polymer donor. As a result, the TDY-α based device delivers a higher device efficiency of 18.1%, and most important, achieves an extrapolated lifetime of about 35000 hours that retaining 80% of their initial efficiency. Our result suggests that with proper geometry design, the tethered small-molecule acceptors can achieve both high device efficiency and operating stability.
- Published
- 2023
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