Planar-type perovskite solar cells have attracted extensive attentions due to their simple architecture and manufacturing. However, an imperfect heterojunction at the electron-selective contact side with abundant detrimental defects and weak binding strength induces severe charge recombination and device instability during long-term operation, which seriously hinders the further development and application prospect. Herein, we demonstrate π-conjugated oxysalt as an efficient interfacial binder and defect passivator for the stabilization of SnO₂/perovskite interface. Theoretical modeling and experimental studies confirm the synergistic effect of ionic bonding and π-cation interaction in reducing defect density and mitigating charge recombination. An impressive power conversion efficiency up to 24.05%, a fill factor as high as 84.52%, and negligible hysteresis can be achieved in optimized solar cell. π-conjugated oxysalt interlayer can also improve device stability by offering a robust interface. Our work highlights the significance of chemical bonding engineering in constructing a high-quality heterojunction for efficient and stable perovskite solar cells.

平面型钙钛矿太阳能电池由于其简单的结构和制造而引起了广泛的关注。然而，电子选择性接触侧不完美的异质结、大量有害缺陷和弱结合强度会在长期运行过程中导致严重的电荷复合和器件不稳定，严重阻碍了进一步的开发和应用前景。在此，我们展示了 π-共轭含氧盐作为一种有效的界面粘合剂和缺陷钝化剂，用于稳定 SnO ₂/钙钛矿界面。理论建模和实验研究证实了离子键和π-阳离子相互作用在降低缺陷密度和减轻电荷复合方面的协同作用。在优化的太阳能电池中，可实现高达 24.05% 的令人印象深刻的功率转换效率、高达 84.52% 的填充因子和可忽略的滞后。π-共轭含氧盐中间层还可以通过提供稳健的界面来提高器件稳定性。我们的工作突出了化学键合工程在为高效稳定的钙钛矿太阳能电池构建高质量异质结中的重要性。