Wang Long, Jiang Wenlin, Guo Shaoting, Wang Senhao, Zhang Mengfan, Liu Zuyuan, Wang Guoliang, Miao Yanqin, Yan Lingpeng, Shao Jiang-Yang, Zhong Yu-Wu, Liu Zitong, Zhang Deqing, Fu Hongbing, Yao Jiannian
Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of Technology Taiyuan 030024 China
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China.
Chem Sci. 2022 Nov 16;13(46):13907-13913. doi: 10.1039/d2sc05580e. eCollection 2022 Nov 30.
Singlet fission (SF) has drawn tremendous attention as a multiexciton generation process that could mitigate the thermal loss and boost the efficiency of solar energy conversion. Although a SF-based solar cell with an EQE above 100% has already been fabricated successfully, the practical efficiency of the corresponding devices is plagued by the limited scope of SF materials. Therefore, it is of great importance to design and develop new SF-capable compounds aiming at practical device application. In the current contribution, a π-expanded strategy, we presented a new series of robust SF chromophores based on polycyclic DPP derivatives, Ex-DPPs. Compared to conventional DPP molecules, Ex-DPPs feature strong absorption with a fivefold extinction coefficient, good molecular rigidity to effectively restrain non-radiative deactivation, and an expanded π-skeleton which endow them with well-suited intermolecular packing geometries for achieving efficient SF process. These results not only provide a new type of high-efficiency SF chromophore but also address some basic guidelines for the design of potential SF materials targeting practical light harvesting applications.
单重态裂变（SF）作为一种多激子产生过程，因其可减少热损失并提高太阳能转换效率而备受关注。尽管已经成功制备出了外量子效率（EQE）高于100%的基于SF的太阳能电池，但相应器件的实际效率却受到SF材料范围有限的困扰。因此，针对实际器件应用设计和开发新型具有SF能力的化合物具有重要意义。在当前的研究中，我们采用一种π扩展策略，提出了一系列基于多环二吡咯并吡咯（DPP）衍生物（Ex-DPPs）的新型稳健的SF发色团。与传统的DPP分子相比，Ex-DPPs具有强吸收和五倍的消光系数、良好的分子刚性以有效抑制非辐射失活，以及扩展的π骨架，这赋予它们适合的分子间堆积几何结构以实现高效的SF过程。这些结果不仅提供了一种新型的高效SF发色团，还为针对实际光捕获应用的潜在SF材料设计提供了一些基本指导原则。
