To achieve efficient harvesting of light energy, perovskite photovoltaics require a surface passivation process of the perovskite layer. In this study, 1-butylmethylimidazolium hexafluorophosphate ionic liquid was adopted as a surface modifier to passivate a perovskite layer through post-treatment. Results revealed that the ionic liquid effectively reduces surface traps by inducing simultaneous interactions from both cation and anion components. Consequently, the surface treatment with the ionic liquid provided a ∼ 15% improvement in the efficiency of the perovskite photovoltaics. However, the formation of perovskite–ionic liquid complex, leading to inefficient charge transport and extraction, was observed when an excess amount of the ionic liquid was used owing to the penetration of the ionic liquid into the photo-active layer. These observations suggest that the ionic liquid should be selectively exposed to the perovskite surface to optimize the efficiency of perovskite photovoltaics treated with ionic liquids.

为了实现光能的有效收集，钙钛矿光伏需要对钙钛矿层进行表面钝化处理。本研究采用1-丁基甲基咪唑六氟磷酸盐离子液体作为表面改性剂，通过后处理钝化钙钛矿层。结果表明，离子液体通过诱导阳离子和阴离子组分的同时相互作用有效地减少了表面陷阱。因此，用离子液体进行表面处理使钙钛矿光伏器件的效率提高了约 15%。然而，由于离子液体渗透到光活性层中，当使用过量的离子液体时，观察到钙钛矿-离子液体复合物的形成，导致电荷传输和提取效率低下。