Lin Yuexin, Liu Jin, Hu Jianfei, Ran Chenxin, Chen Yue, Xing Guichuan, Xia Yingdong, Chen Yonghua
Key Laboratory of Flexible Electronics (KLOFE) & Institution of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), Nanjing 211816, Jiangsu, P.R. China.
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.
ACS Appl Mater Interfaces. 2021 Dec 15;13(49):58809-58817. doi: 10.1021/acsami.1c20045. Epub 2021 Nov 25.
Environment-friendly Tin (Sn)-based perovskite solar cells (PSCs) have lately made significant development, showing tremendous promise in addressing the hazardous problems associated with Pb-based PSCs. However, even in N atmospheres, the thermodynamic stability of Sn-based perovskite films and long-term stability of Sn-based PSCs are demonstrated to be poor due to the presence of interfacial defect trap states. Here, we demonstrate the post-treatment of Sn-based perovskite films with ethylenediamine formate (EDAFa) ion salt, serving as a bi-functional interface layer to in situ passivate the interfacial defect and improve the stability of Sn by creating a thermodynamic chemical environment pathway. Moreover, the presence of EDAFa is shown to promote the interfacial energy level alignment, which is beneficial for the charge extraction at the interface. As a result, PSC devices with a bi-functional interface achieve a champion power conversion efficiency (PCE) as high as 9.40% and enhanced stability, retaining ∼95% of the original PCE stored in a N environment after ∼1960 h without encapsulation. This work highlights the significant role of an interfacial design in efficient and stable Sn-based PSCs.
环境友好型锡（Sn）基钙钛矿太阳能电池（PSC）近来取得了重大进展，在解决与铅基PSC相关的有害问题方面展现出巨大潜力。然而，即便在氮气氛围中，由于存在界面缺陷陷阱态，锡基钙钛矿薄膜的热力学稳定性以及锡基PSC的长期稳定性都较差。在此，我们展示了用甲酸乙二胺（EDAFa）离子盐对锡基钙钛矿薄膜进行后处理，其作为双功能界面层可原位钝化界面缺陷，并通过创建热力学化学环境路径来提高锡的稳定性。此外，EDAFa的存在被证明可促进界面能级对齐，这有利于界面处的电荷提取。结果，具有双功能界面的PSC器件实现了高达9.40%的最佳功率转换效率（PCE）以及增强的稳定性，在未封装的情况下，在氮气环境中储存约1960小时后仍保留约95%的原始PCE。这项工作突出了界面设计在高效稳定的锡基PSC中的重要作用。
