Recent breakthroughs in molecular design have allowed for remarkable achievement in the field of non-fullerene acceptor (NFA)-based organic solar cells (OSCs) with high power conversion efficiencies (PCEs) of over 15%. However, despite such promising advances, the inferior stability of OSCs under operating conditions remains a prominent challenge that must be overcome for their practical realization. Here, versatile ternary photoactive systems with simultaneously enhanced efficiency and photostability are developed by introducing a small amount of fullerene (PC₇₁BM) into a narrow band gap NFA-based bulk heterojunction nanocomposite (PTB7-Th:IEICO-4F); this approach leads to an enhanced PCE of 10.55% and a prolonged lifetime, retaining approximately 80% of the initial PCE after 500 h of operation under continuous illumination. Based on the energy levels and surface energies of the component materials, cascade energetic alignment facilitates electron transfer without trapping. The PTB7-Th/PC₇₁BM interface provides an energy barrier to suppress recombination between holes in PTB7-Th and electrons in IEICO-4F. Moreover, a small amount of PC₇₁BM promotes favorable molecular packing and orientation of IEICO-4F, leading to enhanced electron mobility and balanced charge transport. A study using transient absorption spectroscopy reveals that the ternary blend effectively suppresses the evolution of charge recombination.

中文翻译：

---

具有窄带隙非富勒烯受体和富勒烯添加剂的高效且光稳定的三元有机太阳能电池

分子设计方面的最新突破已经在基于非富勒烯受体（NFA）的有机太阳能电池（OSC）领域取得了令人瞩目的成就，其高功率转换效率（PCE）超过15％。然而，尽管取得了这些令人鼓舞的进步，但OSC在操作条件下的较差稳定性仍然是一个突出的挑战，必须对其进行实际实现加以克服。在这里，通过引入少量的富勒烯，开发了同时提高效率和光稳定性的多功能三元光敏体系（PC ₇₁BM）进入基于NFA的窄带隙本体异质结纳米复合材料（PTB7-Th：IEICO-4F）; 这种方法可将PCE增强10.55％，并延长使用寿命，在连续照明下运行500小时后，可保留大约80％的初始PCE。基于组分材料的能级和表面能，级联高能取向有助于电子转移而不会被俘获。PTB7-Th / PC ₇₁ BM接口提供了一个能垒，以抑制PTB7-Th中的空穴与IEICO-4F中的电子之间的复合。此外，少量的PC ₇₁BM促进IEICO-4F的良好分子堆积和取向，从而增强了电子迁移率和平衡的电荷传输。使用瞬态吸收光谱的研究表明，三元混合物有效地抑制了电荷重组的发展。