High performance organic solar cells (OSCs) are usually realized by using post-treatment and/or additive, which can induce the formation of metastable morphology, leading to unfavorable device stability. In terms of the industrial production, the development of high efficiency as-cast OSCs is crucially important, but it remains a great challenge to obtain appropriate active layer morphology and high power conversion efficiency (PCE). Here, efficient as-cast OSCs are constructed via introducing a new polymer acceptor PY-TPT with a high dielectric constant into the D18:L8-BO blend to form a double-fibril network morphology. Besides, the incorporation of PY-TPT enables an enhanced dielectric constant and lower exciton binding energy of active layer. Therefore, efficient exciton dissociation and charge transport are realized in D18:L8-BO:PY-TPT-based device, affording a record-high PCE of 18.60% and excellent photostability in absence of post-treatment. Moreover, green solvent-processed devices, thick-film (300 nm) devices, and module (16.60 cm²) are fabricated, which show PCEs of 17.45%, 17.54%, and 13.84%, respectively. This work brings new insight into the construction of efficient as-cast devices, pushing forward the practical application of OSCs.

中文翻译：

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通过精细的双原纤维网络形态和改进的活性层介电常数实现高性能铸态有机太阳能电池

高性能有机太阳能电池（OSC）通常通过使用后处理和/或添加剂来实现，这会诱导亚稳态形貌的形成，导致不利的器件稳定性。就工业生产而言，开发高效铸态OSC至关重要，但获得合适的活性层形貌和高功率转换效率（PCE）仍然是一个巨大的挑战。在这里，通过将具有高介电常数的新型聚合物受体 PY-TPT 引入 D18:L8-BO 混合物中形成双原纤维网络形态，构建了高效的铸态 OSC。此外，PY-TPT的加入可以提高活性层的介电常数并降低激子结合能。因此，基于D18:L8-BO:PY-TPT的器件实现了高效的激子解离和电荷传输，在没有后处理的情况下提供了创纪录的18.60%的PCE和优异的光稳定性。此外，还制备了绿色溶剂处理器件、厚膜（300 nm）器件和模块（16.60 cm ²），其PCE分别为17.45%、17.54%和13.84%。这项工作为高效铸态器件的构建带来了新的见解，推动了 OSC 的实际应用。