Unveiling the correlations among molecular structures, morphological characteristics, macroscopic properties and device performances is crucial for developing better photovoltaic materials and achieving higher efficiencies. To achieve this goal, a comprehensive study is performed based on four state-of-the-art non-fullerene acceptors (NFAs), which allows to systematically examine the above-mentioned correlations from different scales. It’s found that extending conjugation of NFA shows positive effects on charge separation promotion and non-radiative loss reduction, while asymmetric terminals can maximize benefits from both terminals. Another molecular optimization is from alkyl chain tuning. The shortened alkyl side chain results in strengthened terminal packing and decreased π-π distance, which contribute high carrier mobility and finally the high charge collection efficiency. With the most-acquired benefits from molecular structure and macroscopic factors, PM6:BTP-S9-based organic photovoltaics (OPVs) exhibit the optimal efficiency of 17.56% (certified: 17.4%) with a high fill factor of 78.44%, representing the best among asymmetric acceptor based OPVs. This work provides insight into the structure-performance relationships, and paves the way toward high-performance OPVs via molecular design.

揭示分子结构、形态特征、宏观性质和器件性能之间的相关性对于开发更好的光伏材料和实现更高的效率至关重要。为了实现这一目标，基于四种最先进的非富勒烯受体（NFA）进行了全面的研究，这使得可以从不同的尺度系统地检查上述相关性。研究发现，NFA 的扩展共轭对促进电荷分离和减少非辐射损耗具有积极作用，而不对称端子可以最大限度地发挥两个端子的优势。另一种分子优化来自烷基链调整。缩短的烷基侧链导致加强的末端堆积和减小的π-π距离，这有助于高载流子迁移率，最终实现高电荷收集效率。凭借从分子结构和宏观因素中获得的最大优势，基于 PM6:BTP-S9 的有机光伏 (OPV) 表现出 17.56% 的最佳效率（认证：17.4%）和 78.44% 的高填充因子，代表了最佳效率。基于不对称受体的 OPV。这项工作提供了对结构与性能关系的深入了解，并为通过分子设计开发高性能 OPV 铺平了道路。