Steering the crystallization of two-dimensional (2D) perovskite film is an important strategy to improve the power conversion efficiency (PCE) of 2D perovskite solar cells (PVSCs). In this paper, the deionized water (H2O) additive is introduced into the perovskite precursor solution to prepare high-quality 2D perovskite films. The 2D perovskite film treated with 3% H2O shows a good surface morphology, increased crystal size, enhanced crystallinity, preferred orientation, and low defect density. The fabricated 2D PVSC with 3% H2O exhibits a higher PCE compared with that without H2O (12.15% vs 2.29%). Furthermore, the shelf stability of unsealed devices with 3% H2O under ambient environment is significantly improved. This work provides a simple method to prepare high-quality 2D perovskite films for efficient and stable 2D PVSCs.

中文翻译：

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通过水添加剂可控制的二维钙钛矿结晶，用于高性能太阳能电池。

指导二维（2D）钙钛矿薄膜的结晶化是提高2D钙钛矿太阳能电池（PVSC）的功率转换效率（PCE）的重要策略。在本文中，将去离子水（H2O）添加剂引入钙钛矿前体溶液中以制备高质量的2D钙钛矿膜。用3％H2O处理的2D钙钛矿薄膜显示出良好的表面形态，增加的晶体尺寸，增强的结晶度，较好的取向和低的缺陷密度。与没有H2O的情况相比，制造的具有3％H2O的2D PVSC表现出更高的PCE（12.15％对2.29％）。此外，在环境条件下使用3％H2O的未密封设备的货架稳定性得到了显着提高。这项工作提供了一种简单的方法来制备高质量2D钙钛矿薄膜，以用于高效稳定的2D PVSC。