Hierarchical morphology has been clearly demonstrated to improve all performance parameters in ternary organic photovoltaics but shows strong dependence on the molecular structures. Here we develop four small molecule electron acceptors with different alkyl chain length to find the optimal solution of alkyl chain towards the defined hierarchical morphology and carry out a clear and comprehensive investigation of the alkyl chain length effects on the structure-morphology-device performance relationships in ternary blend. There is a positive correlation between the power conversion efficiencies of the four ternary systems and their short-circuit current density parameters, manifesting the significance of distinguishing optimal alkyl side chain length of small molecule electron acceptors for defined hierarchical morphology to afford efficient carrier generation. The non-optimal side chains would retard the BTR crystalline and make the PC₇₁BM domain sizes incontrollable, leading to a morphology without a defined hierarchy. Such a detailed mapping of the alkyl side chain length of small molecule electron acceptors provide a new insight into the materials combinations for the next-step high performance multi-component organic photovoltaics

中文翻译：

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三元有机太阳能电池中小分子受体的侧链长度向最佳分层形态的映射

已经清楚地证明了层状形态可改善三元有机光伏中的所有性能参数，但显示出对分子结构的强烈依赖性。在这里，我们开发了四个具有不同烷基链长的小分子电子受体，以找到针对定义的分层形态的烷基链的最佳解决方案，并对烷基链长对结构-形态-器件性能关系的影响进行了清晰而全面的研究。三元混合。四个三元系统的功率转换效率与其短路电流密度参数之间存在正相关关系，证明区分小分子电子受体的最佳烷基侧链长度对于定义的分层形态以提供有效的载流子产生的重要性。非最佳的侧链会阻碍BTR结晶并导致PC_71个BM域大小不可控，导致没有定义层次结构的形态。小分子电子受体的烷基侧链长度的这种详细映射为下一步高性能多组分有机光伏材料的材料组合提供了新的见解