Recent advances in ternary organic solar cells (OSCs) based on O6T-4F have revealed the attractive potential of O6T-4F in developing highly efficient devices. Even so, the exploration of photocurrent generation mechanisms in O6T-4F based devices remains critical and challenging. In this study, we systematically research on exciton separation and charge transport route in ternary OSCs based on PTB7-Th: O6T-4F: PC₇₁BM by novel pump-probe photoconductive (PC) spectroscopy. Detailed studies suggest that, benefiting from the superior molecular structure, O6T-4F plays a dominant role in the photocurrent generating and charge transport. The electron injection rate from the donor to O6T-4F is fivefold larger than PC₇₁BM. The separation of exciton of O6T-4F mainly occurs on the interface with the donor and that at the interface with PC₇₁BM is ignorable. Moreover, for extracting electrons efficiently, a self-assemble monolayer (SAM) of 4-aminobenzoic acid (ABA) is used to modify the ZnO electron transport layer. The optimized ternary OSCs achieve a striking improvement in short-circuit current density (J_sc) and efficiency. This work provides a perspective of viewing the relationship between two acceptors in ternary system and an effective strategy to improve charge transport at the interface.

基于O6T-4F的三元有机太阳能电池（OSC）的最新进展表明，O6T-4F在开发高效器件方面具有诱人的潜力。即便如此，在基于O6T-4F的设备中光电流生成机制的探索仍然至关重要且具有挑战性。在这项研究中，我们通过新颖的泵浦探针光电导（PC）光谱系统研究了基于PTB7-Th：O6T-4F：PC ₇₁ BM的三元OSC中的激子分离和电荷传输途径。详细的研究表明，受益于优越的分子结构，O6T-4F在光电流产生和电荷传输中起着主导作用。从供体到O6T-4F的电子注入速率是PC _71的五倍BM。O6T-4F的激子分离主要发生在与供体的界面上，而与PC ₇₁的界面的BM是可忽略的。此外，为了有效地提取电子，使用4-氨基苯甲酸（ABA）的自组装单分子层（SAM）修饰ZnO电子传输层。优化的三元OSC在短路电流密度（J _sc）和效率方面实现了惊人的提高。这项工作提供了一个视角，可以查看三元系统中两个受体之间的关系，以及改善界面处电荷传输的有效策略。