Lead bromide perovskite with high bandgap and good stability has aroused broad interest for utilization in perovskite solar cells (PSCs) with high photovoltage, especially as a candidate for the front cell of tandem solar cells. However, the efficiency of lead bromide PSCs is still much lower than the standard lead iodide PSCs, and the defects in the perovskite are one of the main limiting factors hindering device performance. The construction of a 2D/3D perovskite interface is an effective way to passivate the interfacial defects and achieve efficient and stable PSCs. Herein, a facile and effective phenethylammonium bromide (PEABr) treatment method was applied to build a 2D/3D perovskite interface in FAPbBr₃ solar cells. An ultrathin layer of 2D PEA₂PbBr₄ perovskite was successfully fabricated on the surface of 3D FAPbBr₃ perovskite by depositing the PEABr solution on the 3D perovskite films. The 2D perovskite layer significantly passivated the interfacial defects, leading to enhancement of power conversion efficiency from 7.7% to 9.4% and fill factor from 67.6% to 77.6%. Moreover, the hydrophobic alkyl chain in the PEA cation improved the moisture tolerance of the perovskite and significantly increases the solar cell stability. Additionally, the PEABr treatment strategy was successfully utilized for preparing semitransparent 2D/3D FAPbBr₃ perovskite solar cells.

中文翻译：

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通过低维钙钛矿层的界面改性获得高效稳定的 FAPbBr3 钙钛矿太阳能电池

具有高带隙和良好稳定性的溴化铅钙钛矿在高光电压钙钛矿太阳能电池（PSC）中的应用引起了广泛的兴趣，特别是作为串联太阳能电池前部电池的候选材料。然而，溴化铅 PSC 的效率仍远低于标准碘化铅 PSC，钙钛矿中的缺陷是阻碍器件性能的主要限制因素之一。构建 2D/3D 钙钛矿界面是钝化界面缺陷并实现高效稳定 PSC 的有效方法。在此，采用简便有效的苯乙基溴化铵 (PEABr) 处理方法在 FAPbBr ₃太阳能电池中构建 2D/3D 钙钛矿界面。2D PEA ₂ PbBr ₄超薄层通过将 PEABr 溶液沉积在 3D 钙钛矿薄膜上，成功地在 3D FAPbBr ₃钙钛矿表面制备了钙钛矿。二维钙钛矿层显着钝化了界面缺陷，导致功率转换效率从 7.7% 提高到 9.4%，填充因子从 67.6% 提高到 77.6%。此外，PEA 阳离子中的疏水烷基链提高了钙钛矿的耐湿性，并显着提高了太阳能电池的稳定性。此外，PEABr 处理策略已成功用于制备半透明的 2D/3D FAPbBr ₃钙钛矿太阳能电池。