Achieving a highly crystalized perovskite active layer with a dense, flat surface and a large grain size is very significant for constructing efficient perovskite solar cells (PSCs). Regarding this, the solvent engineering plays an important role in optimizing perovskite crystallinity and the final device performance. 2-Methoxyethanol (2-ME) is recently reported to be a good processing solvent of a high-quality perovskite film. However, in a conventional one-step fabrication method, little attempt is made to introduce 2-ME as a solvent additive into the N,N-dimethylformamide/dimethyl sulfoxide (DMSO)-based perovskite precursor and study its influences on the quality of the resulting perovskite film. In this report, we demonstrate that 2-ME can be a feasible additive to modify the crystallinity of the perovskite active layer. Samples prepared in the presence of 2-ME show larger grains and less grain boundaries repeatedly. 2-ME also rationalizes DMSO in the CH₃NH₃I–PbI₂–DMSO intermediate film effectively, thus guaranteeing a flat and pin-hole-free film at the same time. Lower levels of traps and trap-assisted recombination are confirmed owing to the morphology improvement. The 2-ME-optimized planar devices yield a higher average power conversion efficiency and a better stability under an ambient atmosphere. This work may provide an alternative method to control the perovskite crystal growth and prepare PSCs with a higher performance and stability.

中文翻译：

---

使用2-甲氧基乙醇添加剂获得的高效钙钛矿太阳能电池：中间膜的形貌和成分控制

获得具有致密，平坦的表面和大晶粒尺寸的高度结晶的钙钛矿活性层对于构建有效的钙钛矿太阳能电池（PSC）非常重要。关于这一点，溶剂工程在优化钙钛矿结晶度和最终装置性能方面起着重要作用。最近报道2-甲氧基乙醇（2-ME）是高质量钙钛矿薄膜的良好加工溶剂。然而，在常规的一步制造方法中，几乎没有尝试将2-ME作为溶剂添加剂引入到N，N中。-基于二甲基甲酰胺/二甲基亚砜（DMSO）的钙钛矿前体，并研究其对所得钙钛矿薄膜质量的影响。在这份报告中，我们证明了2-ME可以作为一种可行的添加剂来改变钙钛矿活性层的结晶度。在2-ME存在下制备的样品反复显示出较大的晶粒和较小的晶界。2-ME还可以使CH ₃ NH ₃ I–PbI _2中的DMSO合理化–DMSO中间膜有效，从而确保同时形成平坦且无针孔的膜。由于形态学的改善，证实了陷阱和陷阱辅助重组的水平较低。经过2-ME优化的平面器件在环境气氛下具有更高的平均功率转换效率和更好的稳定性。这项工作可能提供了控制钙钛矿晶体生长和制备具有更高性能和稳定性的PSC的替代方法。