Lead-free double perovskite, Cs₂AgBiBr₆, with higher stability and lower toxicity than those of its lead counterparts, has been considered a promising alternative for next-generation photovoltaic materials. For practical applications, a facile deposition method that could be used to fabricate high-quality double perovskite films with large grain size is highly desired. However, such kind of facile method has never been established for Cs₂AgBiBr₆. Herein, high-quality Cs₂AgBiBr₆ thin films with an average grain size of approximately 0.5 μm were successfully deposited via a simple one-step spin-coating method by using dimethyl sulfoxide (DMSO)-N,N-dimethylformamide (DMF) mixture with optimized volume ratio as the solvent and chlorobenzene (CB) as the antisolvent. On the basis of satisfactory quality of the film, efficient (>1%) Cs₂AgBiBr₆ perovskite solar cells were constructed. Furthermore, the photo-generated charge-carrier transfer from Cs₂AgBiBr₆ to the adjacent carrier extraction layers was systematically investigated via femtosecond transient spectroscopies. This study offers a new pathway to acquiring high-quality Cs₂AgBiBr₆ thin films and provides a useful guide toward the development of high-efficiency double perovskite solar cells in the future.

无铅双钙钛矿Cs ₂ AgBiBr ₆具有比其铅同类产品更高的稳定性和更低的毒性，被认为是下一代光伏材料的有前途的替代品。对于实际应用，非常需要可用于制造具有大晶粒尺寸的高质量双钙钛矿膜的简便沉积方法。但是，对于Cs ₂ AgBiBr ₆尚未建立这种简便的方法。本文中，使用二甲基亚砜（DMSO）-N通过简单的一步旋涂方法成功沉积了平均粒径约为0.5μm的高质量Cs ₂ AgBiBr ₆薄膜。，Ñ二甲基甲酰胺（DMF）的混合物与优化的体积比作为溶剂和氯苯（CB）作为反溶剂。基于令人满意的薄膜质量，构建了高效的（> 1％）Cs ₂ AgBiBr ₆钙钛矿太阳能电池。此外，通过飞秒瞬态光谱系统研究了从Cs ₂ AgBiBr ₆到相邻载流子提取层的光生载流子转移。这项研究为获得高质量的Cs ₂ AgBiBr ₆薄膜提供了一条新途径，并为将来开发高效双钙钛矿太阳能电池提供了有用的指导。