Zhang Jiayou, Mao Houdong, Zhou Kangkang, Zhang Lifu, Luo Dou, Wang Pei, Ye Long, Chen Yiwang
National Engineering Research Center for Carbohydrate Synthesis/Key Laboratory of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang, 330022, China.
Institute of Polymers and Energy Chemistry (IPEC)/Jiangxi Provincial Key Laboratory of New Energy Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
Adv Mater. 2024 Feb;36(7):e2309379. doi: 10.1002/adma.202309379. Epub 2023 Dec 7.
Flexible organic solar cells (FOSCs) have attracted considerable attention from researchers as promising portable power sources for wearable electronic devices. However, insufficient power conversion efficiency (PCE), intrinsic stretchability, and mechanical stability of FOSCs remain severe obstacles to their application. Herein, an entangled strategy is proposed for the synergistic optimization of PCE and mechanical properties of FOSCs through green sequential printing combined with polymer-induced spontaneous gradient heterojunction phase separation morphology. Impressively, the toughened-pseudo-planar heterojunction (Toughened-PPHJ) film exhibits excellent tensile properties with a crack onset strain (COS) of 11.0%, twice that of the reference bulk heterojunction (BHJ) film (5.5%), which is among the highest values reported for the state-of-the-art polymer/small molecule-based systems. Finite element simulation of stress distribution during film bending confirms that Toughened-PPHJ film can release residual stress well. Therefore, this optimal device shows a high PCE (18.16%) with enhanced (short-circuit current density) J and suppressed energy loss, which is a significant improvement over the conventional BHJ device (16.99%). Finally, the 1 cm flexible Toughened-PPHJ device retains more than 92% of its initial PCE (13.3%) after 1000 bending cycles. This work provides a feasible guiding idea for future flexible portable power supplies.
柔性有机太阳能电池（FOSCs）作为可穿戴电子设备有前景的便携式电源，已引起研究人员的广泛关注。然而，FOSCs的功率转换效率（PCE）不足、固有拉伸性和机械稳定性仍然是其应用的严重障碍。在此，提出一种缠结策略，通过绿色顺序印刷结合聚合物诱导的自发梯度异质结相分离形态，对FOSCs的PCE和机械性能进行协同优化。令人印象深刻的是，增韧伪平面异质结（Toughened-PPHJ）薄膜表现出优异的拉伸性能，裂纹起始应变（COS）为11.0%，是参考本体异质结（BHJ）薄膜（5.5%）的两倍，这是基于聚合物/小分子的最先进体系报道的最高值之一。薄膜弯曲过程中应力分布的有限元模拟证实，Toughened-PPHJ薄膜能够很好地释放残余应力。因此，这种优化后的器件显示出高PCE（18.16%），同时（短路电流密度）J增强且能量损失受到抑制，与传统BHJ器件（16.99%）相比有显著提高。最后，1厘米的柔性Toughened-PPHJ器件在1000次弯曲循环后仍保留其初始PCE（13.3%）的92%以上。这项工作为未来的柔性便携式电源提供了可行的指导思路。
