Passivation, as a classical surface treatment technique, has been widely accepted in start-of-the-art perovskite solar cells (PSCs) that can effectively modulate the electronic and chemical property of defective perovskite surface. The discovery of inorganic passivation compounds, such as oxysalts, has largely advanced the efficiency and lifetime of PSCs on account of its favorable electrical property and remarkable inherent stability, but a lack of deep understanding of how its local configuration affects the passivation effectiveness is a huge impediment for future interfacial molecular engineering. Here, we demonstrate the central-atom-dependent-passivation of oxysalt on perovskite surface, in which the central atoms of oxyacid anions dominate the interfacial oxygen-bridge strength. We revealed that the balance of local interactions between the central atoms of oxyacid anions (e.g., N, C, S, P, Si) and the metal cations on perovskite surface (e.g., Pb) generally determines the bond formation at oxysalt/perovskite interface, which can be understood by the bond order conservation principle. Silicate with less electronegative Si central atoms provides strong O-Pb motif and improved passivation effect, delivering a champion efficiency of 17.26% for CsPbI₂Br solar cells. Our strategy is also universally effective in improving the device performance of several commonly used perovskite compositions.

钝化作为一种​​经典的表面处理技术，已在最先进的钙钛矿太阳能电池（PSC）中被广泛接受，它可以有效地调节有缺陷的钙钛矿表面的电子和化学性质。无机钝化化合物（如含氧盐）的发现，由于其良好的电性能和显着的固有稳定性，大大提高了 PSC 的效率和寿命，但对其局部配置如何影响钝化效率缺乏深入了解是一个巨大的问题。阻碍未来的界面分子工程。在这里，我们展示了含氧盐在钙钛矿表面上的中心原子依赖性钝化，其中含氧酸阴离子的中心原子支配着界面氧桥强度。我们揭示了含氧酸阴离子（例如，N、C、S、P、Si）的中心原子与钙钛矿表面上的金属阳离子（例如，Pb）之间的局部相互作用的平衡通常决定了含氧盐/钙钛矿界面处的键形成，这可以通过键序守恒原理来理解。具有较少电负性 Si 中心原子的硅酸盐提供了强大的 O-Pb 基序和改进的钝化效果，为 CsPbI 提供了 17.26% 的冠军效率₂ Br太阳能电池。我们的策略在提高几种常用钙钛矿组合物的器件性能方面也普遍有效。