溶剂退火制备高质量MA₃Bi₂I₉钙钛矿薄膜与太阳能电池

Solvent Annealing for High Quality MA₃Bi₂I₉ Perovskite Thin Films and Solar Cells

与铅钙钛矿太阳能电池相比,铋基钙钛矿太阳能电池在无毒性和稳定性方面表现出很好的优势。在(CH3NH3)3Bi2I9钙钛矿太阳能电池的研究中,光吸收层薄膜的质量严重制约着电池的光电转化效率。本研究在两步蒸镀与掺氯的基础上,采用DMF气氛退火处理,获得了高致密、无孔洞且大晶粒的(CH3NH3)3Bi2I9薄膜。该处理减少了薄膜内部缺陷,增强薄膜光吸收,增加载流子寿命。与未处理的薄膜相比,电池的光电转换效率提升了52.9%。本研究为钙钛矿薄膜质量的优化以及器件性能的提升提供了可行的解决方案。

Bismuth based perovskite solar cells possess the features of non-toxicity and high stability, which are considered as two significant factors in the emerging perovskite solar cells. The quality of the light absorption layer has a remarkable impact on the conversion efficiency of (CH3NH3)3Bi2I9 per-ovskite solar cells. Herein, (CH3NH3)3Bi2I9 thin films with features of highly compact, pinhole-free and large grains were prepared by procedures of two-step evaporation, chlorine doping and an-nealing under a DMF atmosphere. The DMF solvent annealing can diminish the internal defects of thin-film, and thereby enhances the absorbance as well as prolonging the life time of charge carries. The conversion efficiency shows dramatic enhancement by 52.9% compared with the solar cells from thin-films without DMF annealing. This work provides insights into the (CH3NH3)3Bi2I9 per-ovskite solar cells with optimized thin-film quality and improved device performance.