Liu Feng, Jiang Yuanyuan, Xu Renjie, Su Wenli, Wang Shijie, Zhang Yaogang, Liu Kerui, Xu Shengjie, Zhang Wenkai, Yi Yuanping, Ma Wei, Zhu Xiaozhang
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, China.
Angew Chem Int Ed Engl. 2024 Jan 15;63(3):e202313791. doi: 10.1002/anie.202313791. Epub 2023 Dec 14.
The blend nanomorphology of electron-donor (D) and -acceptor (A) materials is of vital importance to achieving highly efficient organic solar cells. Exogenous additives especially aromatic additives are always needed to further optimize the nanomorphology of blend films, which is hardly compatible with industrial manufacture. Herein, we proposed a unique approach to meticulously modulate the aggregation behavior of NFAs in both crystal and thin film nanomorphology via self-regulation effect. Nonfullerene acceptor Z9 was designed and synthesized by tethering phenyl groups on the inner side chains of the Y6 backbone. Compared with Y6, the tethered phenyl groups participated in the molecular aggregation via the π-π stacking of phenyl-phenyl and phenyl-2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (IC-2F) groups, which induced 3D charge transport with phenyl-mediated super-exchange electron coupling. Moreover, ordered molecular packing with suitable phase separation was observed in Z9-based blend films. High power conversion efficiencies (PCEs) of 19.0 % (certified PCE of 18.6 %) for Z9-based devices were achieved without additives, indicating the great potential of the self-regulation strategy in NFA design.
电子给体（D）和受体（A）材料的共混纳米形态对于实现高效有机太阳能电池至关重要。通常需要添加外源添加剂，尤其是芳香族添加剂来进一步优化共混膜的纳米形态，但这很难与工业制造相兼容。在此，我们提出了一种独特的方法，通过自调节效应精心调控非富勒烯受体（NFAs）在晶体和薄膜纳米形态中的聚集行为。通过在Y6主链的内侧链上连接苯基，设计并合成了非富勒烯受体Z9。与Y6相比，连接的苯基通过苯基 - 苯基和苯基 - 2 -（5,6 - 二氟 - 3 - 氧代 - 2,3 - 二氢 - 1H - 茚 - 1 - 亚基）丙二腈（IC - 2F）基团的π - π堆积参与分子聚集，这诱导了通过苯基介导的超交换电子耦合的三维电荷传输。此外，在基于Z9的共混膜中观察到具有合适相分离的有序分子堆积。在不添加添加剂的情况下，基于Z9的器件实现了19.0%的高功率转换效率（经认证的功率转换效率为18.6%），这表明自调节策略在非富勒烯受体设计中具有巨大潜力。
