Fibrillization of Non-Fullerene Acceptors Enables 19% Efficiency Pseudo-Bulk Heterojunction Organic Solar Cells
Fibrillization of Non-Fullerene Acceptors Enables 19% Efficiency Pseudo-Bulk Heterojunction Organic Solar Cells
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DOI：
10.1002/adma.202208211
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发表时间：
2022-12-18
影响因子：
29.4
通讯作者：
Wang, Tao
中科院分区：
文献类型：
--
作者：
Li, Donghui;Deng, Nan;Wang, Tao
非富勒烯受体（NFA）的结构有序性和聚集性对于它们与电子供体的光伏共混物的光吸收、相分离和电荷传输性质至关重要，并且决定了相应的有机太阳能电池（OSC）的功率转换效率（PCE）。在这项工作中，证明了在稠环溶剂添加剂1-氟萘（FN）的辅助下，小分子NFA L 8-BO的氟化，以显著改善器件PCE。分子动力学模拟表明，FN作为分子桥连接到L 8-BO的主链上，增强了分子间的堆积，诱导L 8-BO一维自组装成具有致密多晶结构的细纤维。L 8-BO原纤维被结合到具有D18作为供体的伪本体异质结（P-BHJ）活性层中，并且显示出增强的光吸收、电荷传输和收集特性，导致D18/L 8-BO二元P-BHJ OSC中的PCE从16.0%增强到前所未有的19.0%，其特征在于80%的高填充因子。这项工作表明了一种策略，使NFA朝着增强的OSC性能。
The structural order and aggregation of non-fullerene acceptors (NFA) are critical toward light absorption, phase separation, and charge transport properties of their photovoltaic blends with electron donors, and determine the power conversion efficiency (PCE) of the corresponding organic solar cells (OSCs). In this work, the fibrillization of small molecular NFA L8-BO with the assistance of fused-ring solvent additive 1-fluoronaphthalene (FN) to substantially improve device PCE is demonstrated. Molecular dynamics simulations show that FN attaches to the backbone of L8-BO as the molecular bridge to enhance the intermolecular packing , inducing 1D self-assembly of L8-BO into fine fibrils with a compact polycrystal structure. The L8-BO fibrils are incorporated into a pseudo-bulk heterojunction (P-BHJ) active layer with D18 as a donor, and show enhanced light absorption, charge transport, and collection properties, leading to enhanced PCE from 16.0% to an unprecedented 19.0% in the D18/L8-BO binary P-BHJ OSC, featuring a high fill factor of 80%. This work demonstrates a strategy for fibrillating NFAs toward the enhanced performance of OSCs.