Abstract：
The interactions between the electron donors and electron acceptors (D/A) play important roles for the performance of organic solar cells (OSCs). While the isomerization strategy is known to optimize molecular geometries and properties, the impacts of isomerization on the donors or acceptors in D/A interactions have not been extensively investigated. Here in, we innovatively investigated the impacts of donor isomerism on the D/A interactions by synthesizing two small molecule donors m-ph-ZnP2 and p-ph-ZnP2 by linking two functionalized porphyrins at the meta and para positions of phenyl groups, respectively. Compared with p-ph-ZnP2, m-ph-ZnP2 displays reduced self-aggregation but with PC61BM. Consequently, a much higher power conversion efficiency (PCE) of 5.43% is achieved for the m-ph-ZnP2 binary OSCs than the p-ph-ZnP2 devices with a PCE of 2.03%. The enhanced performance of m-ph-ZnP2-based device can be primarily attributed to the stronger intramolecular charge transfer (ICT), the enhanced D/A interactions, the improved charge transfer, and the suppressed charge recombination. Furthermore, the ternary devices based on m-ph-ZnP2:Y6:PC61BM achieve a PCE of 8.34%. In short, this work elucidates the relationship among the chemical structure, D/A interactions and device performance, providing valuable guidelines for designing efficient OSCs materials.
摘要：
电子供体和电子受体（D/A）之间的相互作用对有机太阳能电池（OSC）的性能起着重要作用。虽然已知异构化策略可以优化分子的几何形状和性质，异构化对D/A相互作用中供体或受体的影响尚未得到广泛研究。在这里，我们通过在苯基的间位和对位连接两个官能化的卟啉来合成两个小分子供体m-ph-ZnP2和p-ph-ZnP2，创新性地研究了供体异构对D/A相互作用的影响。分别。与p-ph-ZnP2相比，m-ph-ZnP2显示出减少的自聚集，但与PC61BM相比。因此,与PCE为2.03%的p-ph-ZnP2器件相比,m-ph-ZnP2二元OSC实现了5.43%的高得多的功率转换效率(PCE)。基于m-ph-ZnP2的器件的性能增强主要归因于更强的分子内电荷转移（ICT），增强的D/A交互，改进的电荷转移，和抑制的电荷重组。此外，基于m-ph-ZnP2:Y6:PC61BM的三元器件实现8.34%的PCE。总之,这项工作阐明了化学结构之间的关系，D/A交互和设备性能，为设计有效的OSC材料提供有价值的指导。
