Pb-free Sn-based perovskite solar cells (PSCs) have recently made inspiring progress, and power conversion efficiency (PCE) of 14.8% has been achieved. However, due to the energy-level mismatch and poor interfacial contact between commonly used hole transport layer (i.e., poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS) and FASnI₃ film, it is still challenging to effectively extract holes at the interface. Owing to the p-type nature of Sn-based perovskites, the efficient hole extraction is of particular significance to improve the PCE of their solar cells. In this work, for the first time, the role of chiral cations, α-methylbenzylamine (S-/R-/rac-MBA), in promoting hole transportation of FASnI₃-based PSCs is demonstrated. The introduction of MBAs is found to form 2D/3D film with low-dimensional structures locating at PEDOT:PSS/FASnI₃ interface, which facilitates the energy level alignment and efficient charge transfer at the interface. Importantly, chiral-induced spin selectivity (CISS) effect of R-MBA₂SnI₄ induced by chiral R-MBA cation is found to further assist the specific interfacial transport of accumulated holes. As a result, R-MBA-based PSCs achieve decent PCE of 10.73% with much suppressed hysteresis and enhanced device stability. This work opens up a new strategy to efficiently promote the interfacial extraction of accumulated charges in working PSCs.

无铅锡基钙钛矿太阳能电池 (PSC) 最近取得了令人鼓舞的进展，功率转换效率 (PCE) 已达到 14.8%。然而，由于常用的空穴传输层（即聚（3,4-亚乙基二氧噻吩）：聚（苯乙烯磺酸盐）、PEDOT：PSS）和FASnI ₃薄膜之间的能级失配和界面接触不良，这仍然具有挑战性以有效地提取界面处的孔洞。由于 Sn 基钙钛矿的 p 型性质，有效的空穴提取对于提高其太阳能电池的 PCE 具有特别重要的意义。在这项工作中，第一次，手性阳离子的作用，α-甲基苄胺（S - / R - / rac-MBA)，在促进基于FASnI ₃的 PSC 的空穴传输方面得到了证明。发现 MBA 的引入形成了位于 PEDOT:PSS/FASnI ₃界面的具有低维结构的 2D/3D 薄膜，这有助于界面处的能级对齐和有效的电荷转移。重要的是，发现由手性R- MBA 阳离子诱导的R- MBA ₂ SnI ₄的手性诱导自旋选择性 (CISS) 效应进一步有助于累积空穴的特定界面传输。结果，R-基于 MBA 的 PSC 实现了 10.73% 的 PCE，同时大大抑制了滞后现象并增强了设备稳定性。这项工作开辟了一种新策略，可有效促进工作 PSC 中累积电荷的界面提取。