Methylammonium (MA)-free perovskite solar cells (PVSCs) have obtained great attention recently, owing to their superior stability. However, there are still gaps in efficiency between MA-free PVSCs and MA-containing counterparts. Their stability still needs to be further enhanced for meeting commercial standards, especially the illumination stability. Here, we incorporate Zn2+ into perovskite thin films to passivate defects, successfully achieving a champion efficiency of 20.7% and reinforcing the stability of MA-free FA0.9Cs0.1PbI3 PVSCs. This study reveals that Zn-doping can increase the grain size and contribute to modulate the crystallization process. Moreover, it is found that most of the Zn2+ aggregates at the grain boundaries passivating defects and, thus, effectively restrain the non-radiative recombination in the PVSCs. These findings provide a new way of realizing highly efficient and stable PVSCs.

中文翻译：

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ZnI2掺杂对无甲基铵钙钛矿太阳能电池性能的影响

不含甲基铵（MA）的钙钛矿太阳能电池（PVSC）由于其优异的稳定性而近来备受关注。然而，不含 MA 的 PVSC 和含 MA 的 PVSC 之间的效率仍然存在差距。它们的稳定性还需要进一步提高以满足商业标准，尤其是光照稳定性。在这里，我们将 Zn2+ 加入钙钛矿薄膜中以钝化缺陷，成功实现了 20.7% 的冠军效率，并增强了无 MA FA0.9Cs0.1PbI3 PVSC 的稳定性。该研究表明，Zn 掺杂可以增加晶粒尺寸并有助于调节结晶过程。此外，发现大部分 Zn2+ 聚集在晶界钝化缺陷，从而有效地抑制了 PVSC 中的非辐射复合。