Doping a Main-Chain Twisted Wide Bandgap Bifunctional Molecule Enables Efficient Ternary Organic Solar Cells

作者：Xiaoyu Zhang, Weiping Wang, Yuchen Zhou, Shujuan Liu, Zezhou Liang, Wanting Yao, Jiahao Liu, Tianyi Zhao, Zhiyuan Cong, Baofeng Zhao, Wenyan Su, Yuxiang Li, Qinghao Yang, Chao Gao · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.4c09617 · 被引用次数：9 · 研究领域：Organic Electronics and Photovoltaics、Conducting polymers and applications、Nanowire Synthesis and Applications

The rapid development of organic solar cells (OSCs) has been particularly remarkable following the introduction of the high-performance small molecule electron acceptor Y6 and its derivatives. Despite the advances in state-of-the-art OSCs, challenges remain, notably the relatively low open circuit voltage ( V OC ) and charge mobility imbalance, which continue to hinder further improvements in OSCs’ performance. To address these issues, in this work, we synthesized a main-chain twisted wide bandgap small molecule i-IEDTB, which not only possesses superior hole mobility over electron mobility but also has higher lowest unoccupied molecular orbital (LUMO) energy levels, and adopted it as a bifunctional third compound to couple with a high-performance terpolymer Z10 and Y6 based OSC system. The integration of i-IEDTB in the Z10:Y6 blend, either as an acceptor or as a donor, significantly reduces the excessive aggregation of Y6 and facilitates a harmonized distribution of electron and hole mobilities by modulating the crystallization properties of the materials. This strategic intervention leads to a marked improvement in V OC and fill factor (FF). Consequently, the power conversion efficiency (PCE) of the optimized Z10:(Y6: i-IEDTB ) ternary device is elevated to an impressive 17.70%, surpassing the 16.50% of binary Z10:Y6 OSC. Besides, after doping 5% weight i-IEDTB replaced that of Z10, the device’s V OC, and FF were also increased to 0.846 V and 78.08% respectively, resulting ...