Lin Yun, Bai Yang, Fang Yanjun, Chen Zhaolai, Yang Shuang, Zheng Xiaopeng, Tang Shi, Liu Ye, Zhao Jingjing, Huang Jinsong
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States.
Department of Applied Physical Science, University of North Carolina , Chapel Hill, North Carolina 27514, United States.
J Phys Chem Lett. 2018 Feb 1;9(3):654-658. doi: 10.1021/acs.jpclett.7b02679. Epub 2018 Jan 23.
Two-dimensional (2D) perovskites have been shown to be more stable than their three-dimensional (3D) counterparts due to the protection of the organic ligands. Herein a method is introduced to form 2D/3D stacking structures by the reaction of 3D perovskite with n-Butylamine (BA). Different from regular treatment with n-Butylammonium iodide (BAI) where 2D perovskite with various layers form, the reaction of BA with MAPbI only produce (BA)PbI, which has better protection due to more organic ligands in (BA)PbI than the mixture of 2D perovskites. Compared to BAI treatment, BA treatment results in smoother 2D perovskite layer on 3D perovskites with a better coverage. The photovoltaic devices with 2D/3D stacking structures show much improved stability in comparison to their 3D counterparts when subjected to heat stress tests. Moreover, the conversion of defective surface into 2D layers also induces passivation of the 3D perovskites resulting in an enhanced efficiency.
由于有机配体的保护作用，二维（2D）钙钛矿已被证明比其三维（3D）对应物更稳定。本文介绍了一种通过三维钙钛矿与正丁胺（BA）反应形成二维/三维堆叠结构的方法。与用碘化正丁铵（BAI）进行的常规处理不同，在常规处理中会形成具有不同层数的二维钙钛矿，而BA与MAPbI的反应仅生成（BA）PbI，由于（BA）PbI中的有机配体比二维钙钛矿混合物更多，因此具有更好的保护作用。与BAI处理相比，BA处理在三维钙钛矿上产生的二维钙钛矿层更光滑，覆盖率更高。具有二维/三维堆叠结构的光伏器件在进行热应力测试时，与三维对应物相比，稳定性有了很大提高。此外，缺陷表面向二维层的转变也会导致三维钙钛矿的钝化，从而提高效率。
