Chemical passivation implemented by Lewis base has been demonstrated as an effective method to overcome the water vulnerability of perovskite solar cells (PSCs) along with better performance. Comprehensive understanding of the surface passivation effects is crucial to future improve the PSCs efficiency and stability. Herein, we utilized first-principles to simulate the structure and electronic properties of the passivated perovskite, and carried out ab initio molecular dynamics (AIMD) to understand the effectiveness of the experimental passivation molecules, 2-MP, Py, and PTT, on the classical perovskite (Zhu et al., 2019). Calculations show that introducing both -SH and the N atom of 2-MP enhances the electric dipole moment, the binding strength, the adsorption probability and the carrier transfer rate compared to these of Py and PTT. Moreover, the efficient separation of electrons and holes at the interface and the large bandgap can be achieved by the 2-MP treatment, which is beneficial to improve the photovoltaic performance. AIMD simulations indicate that the interactions of N⋯Pb, S⋯Pb, and H⋯I between 2-MP and the MAPbI₃ surface lead to a stronger passivation effect than that of Py and PTT, which is in agreement with the experimental observations. Our results are expected to provide new ideas for developing more distinguished passivation molecules to endow the PSCs stability against water.

路易斯碱实施的化学钝化已被证明是克服钙钛矿太阳能电池 (PSC) 的水脆弱性以及更好的性能的有效方法。全面了解表面钝化效应对于未来提高 PSC 的效率和稳定性至关重要。在此，我们利用第一性原理模拟了钝化钙钛矿的结构和电子特性，并进行了从头分子动力学（AIMD）以了解实验钝化分子2-MP、Py和PTT对经典钙钛矿（Zhu et al., 2019）。计算表明，同时引入 -SH 和2-MP的 N 原子与Py和PTT相比，增强了电偶极矩、结合强度、吸附概率和载流子转移率。此外，2-MP处理可以实现界面处电子和空穴的有效分离和大带隙，有利于提高光伏性能。AIMD 模拟表明，N⋯Pb、S⋯Pb 和 H⋯I 在2-MP和 MAPbI ₃表面之间的相互作用导致比Py和PTT更强的钝化效果，这与实验观察一致。我们的结果有望为开发更出色的钝化分子提供新的思路，以赋予 PSC 对水的稳定性。