Organic photovoltaics (OPVs) have emerged as a promising renewable energy generation technology in past decades. However, the deep understanding of the details in exciton dissociation and carrier recombination in ternary organic solar cells (OSCs) is still lacking. Herein, a novel ternary OSC based on a PTB7‐Th:Y6:ITIC blend with a power conversion efficiency (PCE) enhancement of 29% is reported. A trade‐off is surprisingly found to exist between the exciton dissociation and carrier recombination process. The addition of nonfullerene acceptor Y6 in the ternary blend is found to create an efficient exciton dissociation process but accelerates the free carrier recombination process. Dielectric properties are also studied for ternary OSCs. The addition of Y6 into the binary blend is found to tune down the dielectric constant of the active layer and as a result accelerates the carrier recombination. The best performance is obtained for PTB7‐Th:Y6(5 wt%):ITIC(95 wt%)‐based ternary devices. In addition to its balanced charge carrier mobility and efficient charge extraction process, PTB7‐Th:Y6(5 wt%):ITIC(95 wt%)‐based ternary devices reach a balance in the trade‐off between the exciton dissociation and carrier recombination process and thus achieve the highest short‐circuit current density (J_sc) value.

中文翻译：

---

Y6敏感的非富勒烯三元有机太阳能电池中激子解离和载流子复合与介电性质之间的权衡

在过去的几十年中，有机光伏（OPV）已经成为一种有前途的可再生能源发电技术。但是，仍然缺乏对三元有机太阳能电池（OSC）中激子解离和载流子复合的细节的深刻理解。本文报道了一种基于PTB7-Th：Y6：ITIC共混物的新型三元OSC，其功率转换效率（PCE）增强了29％。令人惊讶地发现在激子离解和载流子重组过程之间存在折衷。发现在三元混合物中添加非富勒烯受体Y6可产生有效的激子离解过程，但可加速自由载流子重组过程。还研究了三元OSC的介电性能。发现将Y 6添加到二元共混物中可降低活性层的介电常数，并因此加速载流子复合。对于基于PTB7-Th：Y6（5 wt％）：ITIC（95 wt％）的三元器件，可以获得最佳性能。除了平衡的电荷载流子迁移率和有效的电荷提取过程外，基于PTB7-Th：Y6（5 wt％）：ITIC（95 wt％）的三元器件还可以在激子离解和载流子重组之间取得平衡过程，从而实现最高的短路电流密度（J _sc）值。