Various internal and external defects present in the perovskite film are one of the main factors that cause low efficiency and stability, and in order to realize high-performance perovskite solar cells, it is necessary to develop a method to effectively suppress them. In this study, a heterofunctional dopants strategy was attempted to integrate the effect of alkali metal cations (Rb⁺ and K⁺) and formate anion (HCOO¯) through doping engineering with alkali-metal formates, i.e., rubidium formate (RbHCOO) and potassium formate (KHCOO). Inclusive physical and photoelectric analysis revealed that doping with a small amount of alkali-metal formate leads to crystal growth and reduction of grain boundaries, and further passivates or inhibits bulk and surface defects. As a result, the photogenerated charge recombination was reduced and the charge carrier transport was improved, leading to improved PSC performance. RbHCOO-doped inverted planar PSCs achieved a PCE of up to 20.41% with long-term stability. Our findings provide a way for producing high-quality perovskite films with low defect densities that are essential for realizing high-performance PSCs.

钙钛矿薄膜中存在的各种内部和外部缺陷是导致效率和稳定性低的主要因素之一，为了实现高性能钙钛矿太阳能电池，有必要开发一种有效抑制它们的方法。在本研究中，尝试了一种异功能掺杂剂策略，通过用碱金属甲酸盐掺杂工程来整合碱金属阳离子（Rb ⁺和 K ⁺）和甲酸阴离子（HCOO¯）的影响，即、甲酸铷（RbHCOO）和甲酸钾（KHCOO）。综合物理和光电分析表明，掺杂少量碱金属甲酸盐会导致晶体生长和晶界减少，并进一步钝化或抑制体缺陷和表面缺陷。结果，减少了光生电荷复合并改善了电荷载流子传输，从而提高了 PSC 性能。RbHCOO 掺杂的倒置平面 PSC 实现了高达 20.41% 的 PCE，并具有长期稳定性。我们的研究结果提供了一种生产具有低缺陷密度的高质量钙钛矿薄膜的方法，这对于实现高性能 PSC 至关重要。