Combining Fused‐Ring and Unfused‐Core Electron Acceptors Enables Efficient Ternary Organic Solar Cells with Enhanced Fill Factor and Broad Compositional Tolerance
Combining Fused‐Ring and Unfused‐Core Electron Acceptors Enables Efficient Ternary Organic Solar Cells with Enhanced Fill Factor and Broad Compositional Tolerance
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结合熔合环和非熔合核心电子受体可实现高效三元有机太阳能电池，具有增强的填充因子和广泛的成分公差
DOI：
10.1002/solr.201900317
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发表时间：
2019
期刊：
影响因子：
7.9
通讯作者：
Hongzheng Chen
中科院分区：
文献类型：
--
作者：
Lingling Zhan;Shuixing Li;Shuhua Zhang;Tsz-Ki Lau;Thomas Rieks Andersen;Xinhui Lu;Minmin Shi;Chang-Zhi Li;Gang Li;Hongzheng Chen
三元共混策略在提高有机太阳能电池（OSC）光伏性能方面显示出巨大的潜力。通常，采用具有相似化学结构的两种受体显示出良好的相容性，但性能的增强有限，而采用具有不同化学结构的两种受体总是具有组成敏感性问题。在本文中，通过将稠环受体IT-M引入到基于非稠核受体HC-PCIC和聚合物供体PBDB-TF的二元共混物中，证明了具有增强的填充因子（FF）和宽的组成公差的高效三元OSC。对三元共混物的光学、电学和形态学性质的详细研究揭示了三元器件的电荷动力学过程和工作机理。研究发现，在PBDB-TF：HC-PCIC二元共混物中加入IT-M不仅使共混物符合类平行模型，而且优化了三元共混物的形态和畴尺寸，减少了陷阱辅助复合，抑制了双分子复合。因此，开路电压（Voc）、短路电流密度（Jsc）和FF协同增强，导致具有0.88 V的高Voc、18.69 mA cm-2的增加的Jsc和具有5% IT-M含量的三元器件的73.82%的增强FF的12.34%的功率转换效率（PCE）的改进。此外，三元OSC的PCE在2.5- 50%的IT-M比率内保持在11%以上，表现出宽的组成公差，这在无富勒烯的三元OSC中很少报道。
The ternary blend strategy has shown great potential to improve the photovoltaic performance of organic solar cells (OSCs). Usually, adopting two acceptors with similar chemical structures shows good compatibility but limited enhancement in performance, whereas adopting two acceptors with different chemical structures always has a compositional sensitivity issue. Herein, a highly efficient ternary OSC with an enhanced fill factor (FF) and a broad compositional tolerance is demonstrated by introducing the fused‐ring acceptor IT‐M to a binary blend based on an unfused‐core acceptor HC‐PCIC and polymer donor PBDB‐TF. Detailed studies on the optical, electrical, and morphological properties of ternary blends reveal the process of charge dynamics and work mechanisms in the ternary device. It is found that the addition of IT‐M into the PBDB‐TF:HC‐PCIC binary blend not only adapts to the parallel‐like model, but also optimizes the morphology and domain sizes in the ternary blend, resulting in a reduced trap‐assisted recombination and suppressed bimolecular recombination. Consequently, open‐circuit voltage (Voc), short‐circuit current density (Jsc), and FF are synergistically enhanced, leading to an improved power conversion efficiency (PCE) of 12.34% with a highVocof 0.88 V, an increasedJscof 18.69 mA cm−2, and an enhanced FF of 73.82% for the ternary device with 5% IT‐M content. Moreover, the PCEs of ternary OSCs remain above 11% within an IT‐M ratio of 2.5–50%, exhibiting a broad compositional tolerance, which is rarely reported in fullerene‐free ternary OSCs.