Given the great potential for achieving record breaking organic solar cells (OSCs), newly explored solid additives that could optimize nanoscale morphology of active layers have rapidly gained widespread attention. Herein, a new volatile solid additive 2,5-dichlorothieno[3,2-b]thiophene (TT-Cl) is delicately explored, fully satisfying the design criteria of a planar conjugated skeleton with suitable molecular size, symmetrical geometry, and proper halogenation. When applied in the state-of-the-art OSCs with diverse active layers, the quite high crystallinity of TT-Cl and strong interactions with light-harvesting components lead to optimized molecular crystalline ordering, fibrillar networks, and vertical phase distributions, thus offering a significant performance enhancement. Consequently, PM6:Y6-based binary and ternary OSCs achieved PCEs of 18.20% and 18.95%, respectively. Moreover, PM6:CH23-based binary OSCs presented an outstanding PCE of 18.72%. Our work not only provides a broad-spectrum solid additive to optimize film morphologies powerfully but also manifests great potential for achieving a record-breaking PCE of OSCs.

中文翻译：

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一种广谱固体添加剂，通过形态调节进一步提高高效有机太阳能电池

鉴于有机太阳能电池（OSC）破纪录的巨大潜力，新开发的可优化活性层纳米级形态的固体添加剂迅速引起了广泛关注。这里，一种新的挥发性固体添加剂2,5-二氯噻吩[3,2- b]噻吩（TT-Cl）经过精心探索，完全满足具有合适分子尺寸、对称几何形状和适当卤化的平面共轭骨架的设计标准。当应用于具有不同活性层的最先进的 OSC 时，TT-Cl 的相当高的结晶度以及与光捕获成分的强烈相互作用导致优化的分子晶体排序、纤维网络和垂直相分布，从而提供显着的性能提升。因此，基于 PM6:Y6 的二元和三元 OSC 分别实现了 18.20% 和 18.95% 的 PCE。此外，基于 PM6:CH23 的二元 OSC 呈现出 18.72% 的出色 PCE。