Comprehensive SummaryMonolithic perovskite/organic tandem solar cells (TSCs) have gained significant attention due to their easy device integration and the potential to surpass the Shockley–Queisser limit of single‐junction solar cells. However, the surfaces of wide‐bandgap perovskite films are densely populated with defects, leading to severe non‐radiative recombination and energy loss. As a consequence, the power conversion efficiency (PCE) of perovskite/organic TSCs lags behind that of other TSC counterparts. To address these issues, we designed a functional ammonium salt, 4‐(2‐hydroxyethyl)piperazin‐1‐ium iodide (PZOI), comprising a piperazine iodide and a terminated hydroxyl group, which was applied for post‐treating the perovskite surface. Our findings reveal that PZOI reacts with and consumes residual PbX2 (X: I or Br) to form a 2D perovskite component, thereby eliminating Pb0 defects, while the terminated hydroxyl group in PZOI can also passivate uncoordinated Pb2+. Consequently, the shallow/deep‐level defect densities of the 2D/3D perovskite film were significantly reduced, leading to an enhanced PCE of single‐junction 2D/3D wide‐bandgap perovskite solar cells to 18.18% with a reduced energy loss of 40 meV. Importantly, the corresponding perovskite/organic TSCs achieved a remarkable PCE of 24.05% with enhanced operational stability (T90 ~500 h).

中文翻译：

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哌嗪辅助构建 2D/3D 宽带隙钙钛矿以实现高效钙钛矿/有机串联太阳能电池

综合总结单片钙钛矿/有机串联太阳能电池（TSC）因其易于设备集成以及超越单结太阳能电池的肖克利-奎瑟极限的潜力而受到广泛关注。然而，宽带隙钙钛矿薄膜的表面缺陷密集，导致严重的非辐射复合和能量损失。因此，钙钛矿/有机 TSC 的功率转换效率（PCE）落后于其他 TSC 同类产品。为了解决这些问题，我们设计了一种功能性铵盐，4-(2-羟乙基)哌嗪-1-碘化鎓(PZOI)，包含碘化哌嗪和末端羟基，用于钙钛矿表面的后处理。我们的研究结果表明，PZOI 会与残留的 PbX 发生反应并消耗掉2(X：I或Br)形成2D钙钛矿组分，从而消除Pb0缺陷，而 PZOI 中的终止羟基也可以钝化不配位的 Pb2+。因此，2D/3D钙钛矿薄膜的浅层/深层缺陷密度显着降低，导致单结2D/3D宽带隙钙钛矿太阳能电池的PCE提高至18.18%，能量损失减少40 meV 。重要的是，相应的钙钛矿/有机 TSC 实现了 24.05% 的显着 PCE，并且运行稳定性增强（时间90〜500小时）。