Halogenated Nonfused Ring Electron Acceptor for Organic Solar Cells with a Record Efficiency of over 17%

作者：Dawei Li, Huarui Zhang, Xinyue Cui, Yanan Chen, Nan Wei, Guangliu Ran, Hao Lu, Shenhua Chen, Wenkai Zhang, Cuihong Li, Yahui Liu, Yuqiang Liu, Zhishan Bo · 发表于：Advanced Materials · 年份：2023 · DOI：10.1002/adma.202310362 · 被引用次数：105 · 研究领域：Organic Electronics and Photovoltaics、Perovskite Materials and Applications、Conducting polymers and applications

Three nonfused ring electron acceptors (NFREAs), namely, 3TT-C2-F, 3TT-C2-Cl, and 3TT-C2, are purposefully designed and synthesized with the concept of halogenation. The incorporation of F or/and Cl atoms into the molecular structure (3TT-C2-F and 3TT-C2-Cl) enhances the π-π stacking, improves electron mobility, and regulates the nanofiber morphology of blend films, thus facilitating the exciton dissociation and charge transport. In particular, blend films based on D18:3TT-C2-F demonstrate a high charge mobility, an extended exciton diffusion distance, and a well-formed nanofiber network. These factors contribute to devices with a remarkable power conversion efficiency of 17.19%, surpassing that of 3TT-C2-Cl (16.17%) and 3TT-C2 (15.42%). To the best of knowledge, this represents the highest efficiency achieved in NFREA-based devices up to now. These results highlight the potential of halogenation in NFREAs as a promising approach to enhance the performance of organic solar cells.