The performance of perovskite solar cells has been continuously improving. However, humidity stability has become a key problem that hinders its promotion in the process of commercialization. A buffer layer deposited by atomic layer deposition is a very helpful method to solve this problem. In this work, MgO film is deposited between Spiro-OMeTAD and electrode by low-temperature atomic layer deposition at 80 °C, which resists the erosion of water vapor, inhibits the migration of electrode metal ions and the decomposition products of perovskite, then finally improves the stability of the device. At the same time, the MgO buffer layer can passivate the defects of porous Spiro, thus enhancing carrier transport efficiency and device performance. The Cs_0.05(FAPbI₃)_0.85(MAPbBr₃)_0.15 perovskite device with a MgO buffer layer has displayed PCE of 22.74%, also with a high V_oc of 1.223 V which is an excellent performance in devices with same perovskite component. Moreover, the device with a MgO buffer layer can maintain 80% of the initial efficiency after 7200 h of storage at 35% relative humidity under room temperature. This is a major achievement for humidity stability in the world, providing more ideas for further improving the stability of perovskite devices.

中文翻译：

---

具有低温原子层沉积氧化镁缓冲层的钙钛矿太阳能电池具有令人印象深刻的 1.223 V 开路电压和高湿度稳定性


钙钛矿太阳能电池的性能不断提高。然而湿度稳定性成为阻碍其在商业化过程中推广的关键问题。通过原子层沉积沉积缓冲层是解决这个问题非常有用的方法。本工作通过80℃低温原子层沉积在Spiro-OMeTAD和电极之间沉积MgO薄膜，该薄膜抵抗水蒸气的侵蚀，抑制电极金属离子的迁移和钙钛矿的分解产物，最终提高了设备​​的稳定性。同时，MgO缓冲层可以钝化多孔Spiro的缺陷，从而提高载流子传输效率和器件性能。具有 MgO 缓冲层的 Cs _0.05 (FAPbI ₃ ) _0.85 (MAPbBr ₃ ) _0.15 钙钛矿器件显示出 22.74% 的 PCE，还具有 1.223 V 的高 V _oc ，这在具有相同钙钛矿组件的器件中具有优异的性能。此外，带有MgO缓冲层的器件在室温35%相对湿度下存储7200小时后仍能保持80%的初始效率。这是世界湿度稳定性方面的重大成就，为进一步提高钙钛矿器件的稳定性提供了更多思路。