Non-fused ring electron acceptors (NFREAs) are regarded as alternative materials for low-cost organic solar cells (OSCs), but their power conversion efficiencies (PCEs) lag behind those of their fused ring counterparts. Herein, we designed and synthesized three NFREAs of FIOTT-4F, HIOTT-4F, and MIOTT-4F with fluorine atoms, hydrogen atoms, and methyl groups on the rigid aromatic side chains, respectively, among which FIOTT-4F with fluorinated aromatic side chains shows the best photovoltaic properties. The interchain interactions orchestrated by F atoms on FIOTT-4F lead to the formation of a compact, well-ordered three-dimensional (3D) charge transport network and improved compatibility with the polymer donor D18, resulting in rapid charge generation and transfer. Consequently, the D18:FIOTT-4F-based OSC gives a champion PCE of 17.5%, the highest value reported for NFREAs-based cells to date. Furthermore, the device exhibits superior photostability: over 80% of the initial PCE is preserved after 200 h 1-sun illumination. This research offers an original example addressing the “efficiency-cost-stability” triangle, thus paving the way to the commercialization of OSCs.

中文翻译：

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通过链间相互作用增强非稠环电子受体的晶体网络和电荷转移，用于高效稳定的有机太阳能电池


非稠环电子受体（NFREA）被认为是低成本有机太阳能电池（OSC）的替代材料，但其功率转换效率（PCE）落后于稠环电子受体。在此，我们设计并合成了三种刚性芳香侧链上分别含有氟原子、氢原子和甲基的NFREA：FIOTT-4F、HIOTT-4F和MIOTT-4F，其中FIOTT-4F具有氟化芳香侧链显示出最佳的光伏性能。 FIOTT-4F 上的 F 原子协调的链间相互作用导致形成紧凑、有序的三维 (3D) 电荷传输网络，并改善与聚合物供体 D18 的兼容性，从而实现快速电荷生成和转移。因此，基于 D18:FIOTT-4F 的 OSC 的冠军 PCE 为 17.5%，这是迄今为止基于 NFREA 的电池报告的最高值。此外，该器件还表现出优异的光稳定性：在 200 小时 1 太阳光照后，80% 以上的初始 PCE 得以保留。这项研究提供了一个解决“效率-成本-稳定性”三角的原创示例，从而为OSC的商业化铺平了道路。