Solvent Tuning of the Active Layer Morphology of Non-Fullerene Based Organic Solar Cells
Solvent Tuning of the Active Layer Morphology of Non-Fullerene Based Organic Solar Cells
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DOI：
10.1002/solr.202101084
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发表时间：
2022-02-23
期刊：
影响因子：
7.9
通讯作者：
Mueller-Buschbaum, Peter
中科院分区：
文献类型：
--
作者：
Grott, Sebastian;Kotobi, Amir;Mueller-Buschbaum, Peter
非富勒烯受体（NFA）基有机太阳能电池近年来取得了巨大的进展。对于纯NFA体系PBDB-T：ITIC，通过选择用于旋涂活性层的溶剂来定制膜形态和结晶度。比较了三种不同的氯化溶剂：氯苯（CB）、氯仿和二氯苯，并将所得的活性层形态与光电性能和器件性能相关。在CB的情况下，小的域尺寸对于器件性能是最有益的，而最大数量或尺寸的正面PBDB-T微晶不会导致最高的功率转换效率（PCE）。此外，当使用CB时，边缘上的微晶的数量是最高的，并且相邻域之间的距离是小的。最光滑的共混物膜实现与CB，表现出相关的粗糙度与它们的基板和没有大的聚集体已形成在这些共混物膜。因此，CB提供了平衡活性层中的聚集和结晶动力学的最佳方式，并实现了最高的PCE值。
Non-fullerene acceptor (NFA)-based organic solar cells have made tremendous progress in recent years. For the neat NFA system PBDB-T:ITIC, the film morphology and crystallinity are tailored by the choice of the solvent used for spin coating the active layers. Three different chlorinated solvents, chlorobenzene (CB), chloroform, and dichlorobenzene, are compared and the obtained active layer morphology is correlated with the optoelectronic properties and the device performance. The small domain sizes in the case of CB are most beneficial for the device performance, whereas the largest number or size of face-on PBDB-T crystallites is not causing the highest power conversion efficiencies (PCEs). In addition, when using CB, the number of edge-on crystallites is highest and the distances between neighboring domains are small. The smoothest blend films are realized with CB, which exhibit correlated roughness with their substrates and no large aggregates have formed in these blend films. Thus, CB offers the best way to balance the aggregation and crystallization kinetics in the active layer and enables the highest PCE values.