Guo Jing, Qin Shucheng, Zhang Jinyuan, Zhu Can, Xia Xinxin, Gong Yufei, Liang Tongling, Zeng Yan, Han Guangchao, Zhuo Hongmei, Li Yuechen, Meng Lei, Yi Yuanping, Chen Jianhui, Li Xiaojun, Qiu Beibei, Li Yongfang
Province-Ministry Co-construction Collaborative Innovation Center of Hebei Photovoltaic Technology, Hebei Key Laboratory of Optic-electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding, Hebei, China.
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2025 Feb 10;16(1):1503. doi: 10.1038/s41467-025-56799-6.
Minimizing the energy loss, particularly the non-radiative energy loss (ΔE), without sacrificing the charge collection efficiency, is the key to further improve the photovoltaic performance of organic solar cells (OSCs). Herein, we proposed an asymmetric molecular design strategy, via developing alkyl/thienyl hybrid side chain based asymmetric small molecule acceptors (SMAs) BTP-C11-TBO and BTP-BO-TBO, to manipulate the intermolecular interactions to realize enhanced luminescence efficiency and reduced energy loss. Theoretical and experimental results indicate that compared to the three symmetric SMAs BTP-DC11, BTP-DTBO and BTP-DBO, the asymmetric SMAs BTP-C11-TBO and BTP-BO-TBO exhibit repressed electron-vibration coupling and reduced ΔE. Moreover, the asymmetric nature of BTP-BO-TBO allows the formation of multiple D:A interfacial conformations and interfacial energies, which have made the charge-transfer state energies closer to that of the strongly absorbing (and emitting) local-exciton state, thus gaining the low ΔE while maintaining efficient exciton dissociation. Consequently, the PM6:BTP-BO-TBO-based OSCs achieve a higher power conversion efficiency of 19.76%, with a high open circuit voltage of 0.913 V and an efficient fill factor of 81.17%, profiting from the more improved and balanced charge mobility and longer carrier lifetime. This work provides molecular design ideas to suppress nonradiative decay and paves the way to obtain high-performance OSCs.
在不牺牲电荷收集效率的前提下，尽量减少能量损失，特别是非辐射能量损失（ΔE），是进一步提高有机太阳能电池（OSC）光伏性能的关键。在此，我们提出了一种不对称分子设计策略，通过开发基于烷基/噻吩基杂化侧链的不对称小分子受体（SMA）BTP-C11-TBO和BTP-BO-TBO，来调控分子间相互作用，以实现增强的发光效率和降低的能量损失。理论和实验结果表明，与三种对称SMA BTP-DC11、BTP-DTBO和BTP-DBO相比，不对称SMA BTP-C11-TBO和BTP-BO-TBO表现出受抑制的电子-振动耦合和降低的ΔE。此外，BTP-BO-TBO的不对称性质允许形成多种D:A界面构象和界面能，这使得电荷转移态能量更接近强吸收（和发射）的局域激子态能量，从而在保持高效激子解离的同时获得低ΔE。因此，基于PM6:BTP-BO-TBO的OSC实现了19.76%的更高功率转换效率，具有0.913 V的高开路电压和81.17%的高效填充因子，这得益于更改善和平衡的电荷迁移率以及更长的载流子寿命。这项工作提供了抑制非辐射衰减的分子设计思路，并为获得高性能OSC铺平了道路。
