Chao Lingfeng, Niu Tingting, Gu Hao, Yang Yingguo, Wei Qi, Xia Yingdong, Hui Wei, Zuo Shouwei, Zhu Zhaohua, Pei Chengjie, Li Xiaodong, Zhang Jing, Fang Junfeng, Xing Guichuan, Li Hai, Huang Xiao, Gao Xingyu, Ran Chenxin, Song Lin, Fu Li, Chen Yonghua, Huang Wei
Frontiers Science Center for Flexible Electronics, Xi'an Institute of Flexible Electronics (IFE) and Xi'an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an 710072, China.
Key Laboratory of Flexible Electronics (KLOFE) & Institution of Advanced Materials (IAM), Nanjing Tech University (Nanjing Tech), Nanjing, 211816 Jiangsu, China.
Research (Wash D C). 2020 Sep 10;2020:2616345. doi: 10.34133/2020/2616345. eCollection 2020.
Environment-friendly protic amine carboxylic acid ionic liquids (ILs) as solvents is a significant breakthrough with respect to traditional highly coordinating and toxic solvents in achieving efficient and stable perovskite solar cells (PSCs) with a simple one-step air processing and without an antisolvent treatment approach. However, it remains mysterious for the improved efficiency and stability of PSCs without any passivation strategy. Here, we unambiguously demonstrate that the three functions of solvents, additive, and passivation are present for protic amine carboxylic acid ILs. We found that the ILs have the capability to dissolve a series of perovskite precursors, induce oriented crystallization, and chemically passivate the grain boundaries. This is attributed to the unique molecular structure of ILs with carbonyl and amine groups, allowing for strong interaction with perovskite precursors by forming C=O…Pb chelate bonds and N-H…I hydrogen bonds in both solution and film. This finding is generic in nature with extension to a wide range of IL-based perovskite optoelectronics.
使用环境友好的质子胺羧酸离子液体（ILs）作为溶剂，相对于传统的高配位且有毒的溶剂而言，是一项重大突破，它能够通过简单的一步空气处理且无需反溶剂处理方法，实现高效稳定的钙钛矿太阳能电池（PSC）。然而，在没有任何钝化策略的情况下，PSC的效率和稳定性提高的原因仍然不明。在此，我们明确证明质子胺羧酸ILs兼具溶剂、添加剂和钝化三种功能。我们发现，ILs能够溶解一系列钙钛矿前驱体，诱导定向结晶，并对晶界进行化学钝化。这归因于ILs具有羰基和胺基的独特分子结构，在溶液和薄膜中都能通过形成C=O…Pb螯合键和N-H…I氢键与钙钛矿前驱体形成强相互作用。这一发现本质上具有普遍性，可扩展到广泛的基于IL的钙钛矿光电器件。
