Intrinsically stretchable organic solar cells (IS-OSCs) are among the most promising technologies for wearable power applications. However, the development of electron acceptors that simultaneously meet the demands for high performance and mechanical stretchability remains a significant challenge. In this study, we creatively synthesized three oligomeric acceptors with flexible linkers (2YF-Br, 4YF-T, and 6YF-BT) and achieved both high efficiency and mechanical robustness in IS-OSCs. Benefiting from an improved fibrous morphology and excellent charge dynamics, rigid OSCs based on 4YF-T demonstrated a superior power conversion efficiency (PCE) of 18.76%, outperforming devices based on 2YF-Br and 6YF-BT. Additionally, the thermal stability of rigid OSCs progressively improved with increasing molecular weight, from 2YF-Br to 6YF-BT. Furthermore, the enlarged molecular weight of the acceptors significantly enhanced mechanical stretchability, with crack-onset strain (COS) values of 16.11%, 20.62%, and 25.92% for 2YF-Br, 4YF-T, and 6YF-BT, respectively. Importantly, as molecular weight increased, the mechanical robustness of IS-OSCs also improved, with 6YF-BT-based devices achieving remarkable stretchability (strain at PCE80% = 35%). This study introduces a new class of high-molecular-weight acceptors with well-defined structures, paving the way for the advancement and practical application of IS-OSCs in wearable electronics.

中文翻译：

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柔性连接的寡聚受体：可拉伸器件的精确合成和增强的光伏/机械性能

本征可拉伸有机太阳能电池 （IS-OSC） 是可穿戴电源应用最有前途的技术之一。然而，开发同时满足高性能和机械可拉伸性的电子受体仍然是一个重大挑战。在这项研究中，我们创造性地合成了三种具有柔性接头的寡聚受体 （2YF-Br、4YF-T 和 6YF-BT），并在 IS-OSCs 中实现了高效率和机械稳健性。得益于改进的纤维形态和出色的电荷动力学，基于 4YF-T 的刚性 OSC 表现出 18.76% 的卓越功率转换效率 （PCE），优于基于 2YF-Br 和 6YF-BT 的器件。此外，刚性 OSC 的热稳定性随着分子量的增加而逐渐提高，从 2YF-Br 到 6YF-BT。此外，受体分子量的增加显著提高了机械拉伸性，2YF-Br、4YF-T 和 6YF-BT 的裂纹起始应变 （COS） 值分别为 16.11%、20.62% 和 25.92%。重要的是，随着分子量的增加，IS-OSC 的机械稳健性也得到了提高，基于 6YF-BT 的器件实现了显着的拉伸性（PCE80% = 35% 时的应变）。本研究介绍了一类具有明确结构的新型高分子量受体，为 IS-OSC 在可穿戴电子产品中的进步和实际应用铺平了道路。