Ternary blends have shown great potential to increase the power conversion efficiency (PCE) of organic solar cells (OSCs). In this work, we studied a ternary OSC system with a donor polymer (PM6) and two structurally similar non-fullerene acceptors (named ITCPTC and MeIC). Although these two small molecular acceptors (SMAs) exhibit similar absorption spectra, they introduce a surprising synergistic effect on tuning the domain size and crystallinity of the OSC blend. More specifically, MeIC is a SMA with strong crystallinity, which results in excessive phase segregation and large domain size for the PM6:MeIC binary blend. By adding a structurally similar and less crystalline SMA (ITCPTC) into the binary blend, the domain size and morphology of the blend are much improved without sacrificing the electron mobility of the blend. As a result, the optimal blend ratio of PM6 : ITCPTC : MeIC (1 : 0.4 : 0.6) led to an impressive FF of 78.2% and PCE of 14.13%, which are the highest values reported for ternary non-fullerene OSCs reported to date.

中文翻译：

---

使用两个结构相似的小分子受体，从而使三元有机太阳能电池具有较高的效率和填充系数†

三元混合物显示出巨大的潜力，可以提高有机太阳能电池（OSC）的功率转换效率（PCE）。在这项工作中，我们研究了具有供体聚合物（PM6）和两个结构相似的非富勒烯受体（分别称为ITCPTC和MeIC）的三元OSC系统。尽管这两个小分子受体（SMA）表现出相似的吸收光谱，但它们在调节OSC共混物的畴尺寸和结晶度方面产生了令人惊讶的协同效应。更具体地说，MeIC是具有强结晶度的SMA，对于PM6：MeIC二元共混物，会导致过度的相偏析和较大的畴尺寸。通过在二元共混物中添加结构相似且结晶度较低的SMA（ITCPTC），可在不牺牲共混物电子迁移率的情况下大大改善共混物的畴尺寸和形貌。因此，