Wang Yeye, Yang Mingqun, Chen Zhili, Zhong Jianbin, Zhao Feixiang, Wei Wenkui, Yuan Xiyue, Zhang Wei, Ma Zaifei, He Zhicai, Liu Zhitian, Huang Fei, Cao Yong, Duan Chunhui
Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, PR China.
Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials, South China University of Technology, Guangzhou, PR China.
Nat Commun. 2025 Jul 1;16(1):5449. doi: 10.1038/s41467-025-60650-3.
Toward commercialization of organic solar cells (OSCs), photoactive materials that enable high efficiency yet possess low cost should be developed. Fully non-fused ring electron acceptors (FNEAs) that extend the conjugated skeleton with carbon-carbon (C-C) single bonds solely have lower synthetic costs than their fused-ring counterparts. However, the power conversion efficiencies (PCEs) of FNEAs are lagging due to low acceptor crystallinity and difficulty in the formation of fibrillary bi-continuous interpenetrating network morphology. Herein, we report four FNEAs (NEH-4F, EEH-4F, NBO-4F, and EBO-4F) through rational design of peripheral substituents. Specifically, the encapsulated central core guarantees the planarity of the conjugated skeleton and improves acceptor crystallinity, while the lengthened outer side chains modulate the molecular stacking and regulate the thermodynamic compatibility between the FNEAs and the polymer donor PTTz. Therefore, nanoscale phase separation morphology with bi-continuous interpenetrating fibril network structures was found in the blend of PTTz:EBO-4F, which promotes exciton diffusion and charge transport in solar cells. A record-breaking PCE of 18.04% is thus obtained, which greatly reduces the efficiency gap between FNEAs and fused-ring electron acceptors. These results demonstrate the promising prospect of fabricating high-efficiency OSCs from low-cost FNEAs through rational molecular design.
为了实现有机太阳能电池（OSCs）的商业化，需要开发出兼具高效率和低成本的光活性材料。仅通过碳 - 碳（C - C）单键扩展共轭骨架的全非稠环电子受体（FNEAs），其合成成本低于稠环同类物。然而，由于受体结晶度低以及难以形成纤维状双连续互穿网络形态，FNEAs的功率转换效率（PCEs）滞后。在此，我们通过合理设计外围取代基报告了四种FNEAs（NEH - 4F、EEH - 4F、NBO - 4F和EBO - 4F）。具体而言，封装的中心核保证了共轭骨架的平面性并提高了受体结晶度，而延长的外侧链调节分子堆积并调节FNEAs与聚合物供体PTTz之间的热力学相容性。因此，在PTTz:EBO - 4F的共混物中发现了具有双连续互穿纤维网络结构的纳米级相分离形态，这促进了太阳能电池中的激子扩散和电荷传输。由此获得了创纪录的18.04%的PCE，这大大缩小了FNEAs与稠环电子受体之间的效率差距。这些结果证明了通过合理的分子设计从低成本FNEAs制备高效OSCs的广阔前景。
