Molecular Geometry‐Property Relationship of Benzodipyrrole‐Based A‐DA'D‐A Type Acceptors for High‐Performance Organic Solar Cells

作者：Yufei Gong, Senke Tan, Xiaojun Li, Shucheng Qin, Xiangjin Li, Tianwei Zou, Yuechen Li, Yuechen Li, Meng Yuan, Ziyue Zhang, Huawei Hu, Tongling Liang, Jinyuan Zhang, Lei Meng, Feng Liu, Yongfang Li, Yongfang Li · 发表于：Angewandte Chemie International Edition · 年份：2025 · DOI：10.1002/anie.202505366 · 被引用次数：16 · 研究领域：Conducting polymers and applications、Organic Electronics and Photovoltaics、Perovskite Materials and Applications

Molecular geometry plays a crucial role in determining the physical and chemical properties of organic semiconductor materials. However, there is little research on the molecular geometry-property relationship of A-DA'D-A type small molecule acceptors (SMAs), which are the most representative organic semiconductor materials used in organic solar cells (OSCs). In this work, we used dichlorine-substituted benzene as the A' unit to overcome the geometry constraints imposed by the conventional A' unit that has a large size. Four isomers of benzodipyrrole-based SMAs (C-Cl46-Cl, Ɂ-Cl46-Cl, M-Cl46-Cl, and S-Cl46-Cl) with C-, Ɂ-, M-, and S-shaped molecular geometries were synthesized, and the effect of molecular geometry on their photovoltaic performance was studied. We revealed that the molecular geometry influences the physicochemical and photovoltaic properties in three aspects: 1) intrinsic physicochemical properties, including energy levels, absorption, and reorganization energy; 2) molecular stacking pattern, which governs the exciton diffusion and charge transport processes; and 3) donor-acceptor interaction and miscibility. We found that the C-shaped molecular geometry possesses a suitable energy level and absorption range, dense and ordered molecular stacking, and improved donor-acceptor interaction and miscibility. These advantages enable a record-high power conversion efficiency (PCE) of 19.94% (certified as 19.54%) for the binary OSCs based on D18:C-Cl46-Cl active layer. ...