The past decade has seen a tremendous development of organic solar cells (OSCs). To date, high-performance OSCs have boosted power conversion efficiencies (PCEs) over 17%, showing bright prospects toward commercial applications. Compared with binary OSCs, ternary OSCs, by introducing a third component as a second donor or acceptor into the active layer, have great potential in realizing outstanding photovoltaic performance. Herein, a comprehensive review of the recent advances of ternary solar cells is presented. According to the chemical components of active layer materials, we classify the ternary systems into four categories, including polymer/small molecule/small molecule, polymer/polymer/small molecule, all-polymer and all-small-molecule types. The relationships among the photovoltaic materials structure and weight ratio, active layer morphology and photovoltaic performance are systematically analyzed and summarized. The features and design strategies of each category are also discussed and summarized. Key issues and challenges faced in ternary OSCs are pointed out, and potential strategies and solutions are proposed. This review may provide guidance for the field of ternary OSCs.

中文翻译：

---

三元有机太阳能电池的最新进展，挑战和前景

在过去的十年中，有机太阳能电池（OSC）取得了巨大的发展。迄今为止，高性能OSC已将功率转换效率（PCE）提升了17％以上，在商业应用中显示出光明的前景。与二元OSC相比，三元OSC通过将第三组分作为第二施主或受主引入有源层中，在实现出色的光伏性能方面具有巨大潜力。在此，对三元太阳能电池的最新进展进行了全面回顾。根据活性层材料的化学成分，我们将三元体系分为四类，包括聚合物/小分子/小分子，聚合物/聚合物/小分子，全聚合物和全小分子类型。光伏材料结构与重量比之间的关系，对活性层的形貌和光伏性能进行了系统的分析和总结。还讨论并总结了每个类别的功能和设计策略。指出了三元OSC面临的关键问题和挑战，并提出了潜在的策略和解决方案。该综述可以为三元OSC领域提供指导。