北京航空航天大学孙艳明团队揭示了具有小单重态-三重态能量间隙的二聚体受体可以抑制三重态损失，实现20.85%的有机太阳能电池效率。2025年12月15日，《德国应用化学》杂志发表了这一成果。

相对较高的非辐射能量损失已成为制约有机太阳能电池（OSCs）性能提高的主要因素，其中三重态激子的形成是主要障碍。在低带隙受体中，缩小第一单重态和三重态激发态之间的能隙（ΔE_ST）被认为是缓解这一问题的有效策略。

在这项工作中，研究组设计并合成了一个二聚体受体，DY-TXT，利用热激活延迟荧光（TADF）分子作为桥接单元。与传统的非富勒烯受体相比，这种新型结构具有更高的光致发光量子产率和显著降低的ΔE_ST （~0.1 eV）。加入D18:L8-BO宿主体系后，DY-TXT提高了电致发光量子效率，显著抑制了三重态激子的产生，从而减少了三重态的能量损失。小的ΔE_ST也促进反向系统间交叉过程，使三重态激子的循环。因此，所得到的三元器件实现了0.194 eV的低非辐射能量损失和20.85%的出色功率转换效率。这项工作证明了一种有效的策略来抑制三重体介导的能量损失，并为提高OSCs的性能提供了一个有希望的途径。

附：英文原文

Title: Dimeric Acceptor with Small Singlet-Triplet Energy Gap Enables Suppressed Triplet Loss and 20.85% Efficiency of Organic Solar Cells

Author: Lingzhi Guo, Lunbi Wu, Huotian Zhang, Yiyang Pan, Xiaoming Li, Xiaobin Dong, Jingyi Kong, Min Hun Jee, Minqiang Mai, Sha Liu, Han Young Woo, Tao Jia, Zujin Zhao, Feng Gao, Zhen Wang, Yanming Sun

Issue&Volume: 2025-12-15

Abstract: The relatively high non-radiative energy loss has become a major limiting factor for improving the performance of organic solar cells (OSCs), with triplet exciton formation being a primary source. Narrowing the energy gap between the first singlet and triplet excited states (ΔEST) in low-bandgap acceptors is considered an effective strategy to mitigate this issue. In this work, we design and synthesize a dimeric acceptor, DY-TXT, utilizing a thermally activated delayed fluorescence (TADF) molecule as the bridging unit. This novel structure exhibits a higher photoluminescence quantum yield and a significantly reduced ΔEST (～0.1 eV) compared to conventional nonfullerene acceptors. When incorporated into the D18:L8-BO host system, DY-TXT enhances the electroluminescence quantum efficiency and markedly suppresses triplet exciton generation, thereby reducing energy loss via triplet states. The small ΔEST also facilitates reverse intersystem crossing process, enabling recycling of triplet excitons. Consequently, the resulting ternary device achieves a low non-radiative energy loss of 0.194 eV and an outstanding power conversion efficiency of 20.85%. This work demonstrates an effective strategy for suppressing triplet-mediated energy losses and provides a promising avenue for advancing the performance of OSCs.

DOI: 10.1002/anie.202524341

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202524341