摘要
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 Cs2AgBiBr6thin films with an average grain size of approximately 0.5μm were successfully deposited via a simple onestep 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%)Cs2AgBiBr6perovskite solar cells were constructed.Furthermore,the photo-generated charge-carrier transfer from Cs2AgBiBr6to the adjacent carrier extraction layers was systematically investigated via femtosecond transient spectroscopies.This study offers a new pathway to acquiring high-quality Cs2AgBiBr6thin 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Cs2AgBiBr6与铅基钙钛矿相比具有更高的稳定性和更低的毒性,被认为是很有前途的下一代光伏材料.在实际应用中,人们迫切需要一种简便的沉积方法来制备高质量、大晶粒尺寸的双钙钛矿薄膜.然而,目前尚未找到制备Cs2AgBiBr6薄膜的简便方法.本文通过简单的一步旋涂法成功制备了晶粒尺寸达0.5μm的高质量Cs2AgBiBr6薄膜,该方法使用体积比优化后的二甲基亚砜-二甲基甲酰胺(DMSO-DMF)混合溶液作为溶剂,氯苯作为反溶剂.基于良好的薄膜质量,制备了高效(>1%)Cs2AgBiBr6钙钛矿太阳能电池.此外,利用飞秒瞬态光谱系统地研究了Cs2AgBiBr6与相邻的载流子传输层之间的光生电荷转移.本工作为制备高质量的Cs2AgBiBr6薄膜开辟了新方法,为高效双钙钛矿太阳能电池的发展提供了有益指导.
基金
financial support from Macao Science and Technology Development Fund(FDCT-116/2016/A3,FDCT-091/2017/A2 and FDCT-014/2017/AMJ)
the Research Grants(SRG2016-00087-FST,MYRG2018-00148-IAPME)from University of Macao
the National Natural Science Foundation of China(91733302,61605073,61935017)
the Natural Science Foundation of Guangdong Province,China(2019A1515012186)。
