Wide‐bandgap (WBG) perovskite solar cells (PSCs) play a crucial role in advancing perovskite‐based tandem solar cells. In WBG perovskite films, grain boundary (GB) defects are the main contributors to open‐circuit voltage (VOC) deficits and performance degradation. This report presents an effective strategy for passivating GBs by incorporating an inorganic protective layer and reducing the density of GBs in perovskite films. This is achieved by integrating potassium thiocyanate (KSCN) into I‐Br mixed halide WBG perovskites. It is reported for the first time that the incorporation of KSCN creates band‐shaped barriers along the GBs. In addition, KSCN enlarges the grains of perovskite film. Elemental and structural analyses reveal that these barriers are composed of potassium lead halide. Incorporating KSCN significantly enhances the fill factor and VOC of WBG single‐junction PSCs by reducing trap density. This results in high power conversion efficiencies of 19.22% (bandgap of 1.82 eV), 20.45% (1.78 eV), and 21.54% (1.70 eV) with a C60/bathocuproine electron transport layer, and 18.51% (1.82 eV) with a C60/SnO2. Furthermore, both operational and shelf stabilities are significantly improved due to reduced light‐induced halide segregation. By using inorganic‐halide‐passivated WBG sub‐cells, a monolithic all‐perovskite tandem solar cell with an efficiency of 27.04% is demonstrated.

中文翻译：

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用纳米级无机卤化物势垒稳定宽带隙钙钛矿，用于下一代串联技术


宽带隙 （WBG） 钙钛矿太阳能电池 （PSC） 在推进基于钙钛矿的串联太阳能电池中起着至关重要的作用。在 WBG 钙钛矿薄膜中，晶界 （GB） 缺陷是导致开路电压 （VOC） 缺陷和性能下降的主要因素。本报告提出了一种通过掺入无机保护层和降低钙钛矿薄膜中 GB 的密度来钝化 GB 的有效策略。这是通过将硫氰酸钾 （KSCN） 整合到 I-Br 混合卤化物 WBG 钙钛矿中来实现的。首次报道，KSCN 的掺入会沿着 GB 产生带状屏障。此外，KSCN 扩大了钙钛矿薄膜的晶粒。元素和结构分析表明，这些屏障由卤化铅钾组成。掺入 KSCN 通过降低捕集阱密度，显著提高了 WBG 单液接 PSC 的填充因子和 VOC。这导致 C60/巴苏普罗因电子传输层的高功率转换效率为 19.22%（带隙为 1.82 eV）、20.45% （1.78 eV） 和 21.54% （1.70 eV），C60/SnO2 为 18.51% （1.82 eV）。此外，由于光诱导卤化物偏析减少，操作和货架稳定性都得到了显著提高。通过使用无机卤化物钝化 WBG 子电池，展示了一种效率为 27.04% 的单片全钙钛矿叠层太阳能电池。