The photovoltaic property of perovskite solar cells (PSCs) is affected by detrimental defects located at the bulk and surface of perovskite films. Furthermore, defect passivation of the perovskite films is challenging. Herein, we add solid CsCl to PbI₂ precursor solutions to adjust the properties of PbI₂ membranes and obtain perovskite layers with a micrometer-sized grain by reducing grain boundary defects. Bulk defects are reduced by the increase in grain size and decrease in grain boundaries. Fewer bulk defects and the incorporation of Cs increase the device performance, improving the power conversion efficiency (PCE) from 19.72% to 22.24% and suppressing hysteresis. The passivation of surface defects further increases the PCEs and open-circuit voltages (V_OC) of PSCs. Therefore, we use 4-methoxyphenethylamine (CH₃O–PEAI) to modify the CsCl perovskite films to eliminate the surface defects and suppress nonradiative charge recombination. The surface defect passivation using CH₃O–PEAI further improves the PCE of the PSCs to 23.25% with a V_OC of 1.186 V, resulting in more efficient and stable PSCs.

中文翻译：

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通过体和表面缺陷钝化改善平面钙钛矿太阳能电池的性能

钙钛矿太阳能电池 (PSC) 的光伏特性受到位于钙钛矿薄膜体部和表面的有害缺陷的影响。此外，钙钛矿薄膜的缺陷钝化具有挑战性。在此，我们将固态 CsCl 添加到 PbI ₂前驱体溶液中，以调节 PbI ₂膜的性能，并通过减少晶界缺陷获得具有微米级晶粒的钙钛矿层。通过晶粒尺寸的增加和晶界的减小来减少体缺陷。更少的体缺陷和 Cs 的掺入提高了器件性能，将功率转换效率 (PCE) 从 19.72% 提高到 22.24% 并抑制了滞后。表面缺陷的钝化进一步增加了 PCE 和开路电压（V_OC ) 的 PSC。因此，我们使用 4-甲氧基苯乙胺 (CH ₃ O-PEAI) 对 CsCl 钙钛矿薄膜进行改性，以消除表面缺陷并抑制非辐射电荷复合。使用 CH ₃ O-PEAI的表面缺陷钝化进一步将 PSC 的 PCE 提高到 23.25%，V _OC为 1.186 V，从而产生更高效和更稳定的 PSC。