物理化学学报

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扭曲的噻吩端基受体用于降低有机太阳能电池中的非辐射能量损失并实现20.79%的光电转化效率

周晟熙1,3, 戴海娟2, 肖承义1, 李梦迪1, 李加雨1, 张雅楠1, 李鹏风1, 于冬宏3,4, 王二刚5, 李韦伟1   

  1. 1 北京化工大学软物质科学与工程北京先进创新中心，有机无机复合材料国家重点实验室，北京 100029;
    2 威海拓展纤维有限公司，山东 威海 264211;
    3 Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark; Sino-Danish Center for Education and Research, Aarhus, Denmark;
    4 Sino-Danish Center for Education and Research, Aarhus, Denmark;
    5 Department of Chemistry and Chemical Engineering, Chalmers University of Technology, G?teborg, Sweden
  • 收稿日期:2026-06-20 修回日期:2026-08-28 录用日期:2026-08-30
  • 通讯作者: 戴海娟, 肖承义, 于冬宏, 李韦伟Haijuan Dai, Chengyi Xiao, Donghong Yu, Weiwei Li E-mail:du7758521dai@163.com;xiaocy@mail.buct.edu.cn;yu@bio.aau.dk;liweiwei@iccas.ac.cn
  • 基金资助:
    国家自然科学基金(52473165, 22475013)、中央高校基本科研业务费(buctrc201828, XK1802-2) 、超分子结构与材料国家重点实验室开放课题基金(sklssm202622)。

Suppressing nonradiative energy loss in organic solar cells with 20.79% efficiency via thiophene-terminal engineering of a twisted acceptor

Shengxi Zhou1,3, Haijuan Dai2, Chengyi Xiao1, Mengdi Li1, Jiayu Li1, Yanan Zhang1, Pengfeng Li1, Donghong Yu3,4, Ergang Wang5, Weiwei Li1   

  1. 1 Beijing Advanced Innovation Center for Soft Matter Science and Engineering & State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China;
    2 Weihai Tuozhan Fiber Limited Company, Weihai 264211, Shandong Province, China;
    3 Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark; Sino-Danish Center for Education and Research, Aarhus, Denmark;
    4 Sino-Danish Center for Education and Research, Aarhus, Denmark;
    5 Department of Chemistry and Chemical Engineering, Chalmers University of Technology, G?teborg, Sweden
  • Received:2026-06-20 Revised:2026-08-28 Accepted:2026-08-30

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摘要： 降低非辐射能量损失是提高有机太阳能电池光伏性能的关键要素。针对这一问题，本研究提出了一种噻吩端基修饰策略，成功设计并合成了具有扭曲分子构象的小分子受体AQx-2T。通过用给电子性噻吩取代传统吸电子性端基IC-2F，分子内电荷转移得到有效减弱，LUMO能级变浅，并在D18:AQx-2T二元器件中实现了超过1.0 V的高开路电压(VOC)。除了能级调控，C–C单键连接的噻吩能够自由旋转，破坏了AQx-2T的分子平面性，从而抑制分子过度聚集并降低其结晶度。因此，AQx-2T实现了超低的ΔEnr(0.182 eV)。其作为客体受体引入D18:L8-BO二元体系时，AQx-2T与L8-BO受体共组装，调节了分子有序性，抑制了大尺度相分离，构建了更加均衡的给–受体互穿网络结构。此外，D18:L8-BO二元体系的ΔEnr数值是0.216 eV，在三元体系中降低至0.197 eV。最终，优化后的三元D18:L8-BO:AQx-2T器件获得了20.79%的光电转换效率。本研究为提高有机太阳能电池的开路电压及新型三元体系的合理设计提供了宝贵见解。

关键词: 有机太阳能电池, 小分子受体, 端基工程, 非辐射能量损失, 开路电压

Abstract: Minimizing nonradiative energy loss (ΔEnr) is a critical imperative for bridging the efficiency gap in organic solar cells (OSCs). Herein, we demonstrate a thiophene-terminal engineering strategy to develop a twisted small-molecule acceptor, named AQx-2T. By substituting conventional terminal groups with electron-donating thiophene moieties, the intramolecular charge-transfer character is effectively moderated, leading to upshifted frontier molecular orbitals and a high open-circuit voltage (VOC) exceeding 1.0 V in D18:AQx-2T binary devices. Crucially, the rotational freedom of the thiophene linkages induces a more twisted molecular conformation, which successfully mitigates excessive aggregation and reduces crystallinity. Consequently, AQx-2T achieves an ultralow ΔEnr of 0.182 eV. When introduced as a guest acceptor into the highly crystalline D18:L8-BO host matrix, AQx-2T promotes acceptor co-assembly, moderates molecular ordering, suppresses large-scale phase separation, and refines the bulk-heterojunction morphology. Benefiting from improved exciton dissociation, balanced charge transport, and minimized recombination, the optimized ternary D18:L8-BO:AQx-2T device achieves an outstanding power conversion efficiency of 20.79%, accompanied by a reduced ΔEnr from 0.216 eV to 0.197 eV. This work demonstrates that balancing molecular planarity and electronic structures via terminal engineering provides a powerful paradigm for overcoming the voltage deficit in high-performance OSCs.

Key words: Organic Solar Cells, Small Molecule Acceptors, Terminal Engineering, Nonradiative Energy Loss, Open-circuit Voltage