The use of superlattice structures is an attractive strategy for expanding the family of perovskites and obtaining excellent optoelectronic materials. Mixing of cations and partial replacement of halogens by superhalogens are advantageous for improving the stability and optoelectronic properties of hybrid perovskites. Herein, the superlattice structures of the (CsPbI₃)_n/MAPbI₂BF₄, (FAPbI₃)_n/MAPbI₂BF₄, (MAPbI₃)_n/CsPbI₂BF₄, and (FAPbI₃)_n/CsPbI₂BF₄ hybrid perovskites were investigated using first-principles density functional theory calculations. The results show that these superlattice structures have tunable direct band gaps and small effective electron and hole masses. Additionally, the charge densities for the valence band maximum and conduction band minimum states are located in different regions of the superlattices. Suggesting that these structures are type-II superlattices that show greatly reduced electron–hole recombination rates. Excellent optical absorption properties for all of perovskite superlattices and the calculated power conversion efficiency of 22.77% for the single-junction solar cells based on the (FAPbI₃)₃/MAPbI₂BF₄ and (FAPbI₃)₃/CsPbI₂BF₄ perovskites were obtained.

中文翻译：

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基于有机-无机卤化物钙钛矿和超卤素杂化钙钛矿超晶格结构的高性能光伏材料。

超晶格结构的使用是扩大钙钛矿家族并获得优质光电材料的一种有吸引力的策略。阳离子的混合和用超卤素部分取代卤素是有利于改善杂化钙钛矿的稳定性和光电性能的。在此，（CsPbI ₃）_n / MAPbI ₂ BF ₄，（FAPbI ₃）_n / MAPbI ₂ BF ₄，（MAPbI ₃）_n / CsPbI ₂ BF ₄和（FAPbI ₃）_n / CsPbI ₂ BF的超晶格结构使用第一性原理密度泛函理论计算研究了₄种杂化钙钛矿。结果表明，这些超晶格结构具有可调的直接带隙和较小的有效电子和空穴质量。另外，价带最大和导带最小状态的电荷密度位于超晶格的不同区域。这表明这些结构是II型超晶格，显示出大大降低的电子-空穴复合速率。基于（FAPbI ₃）₃ / MAPbI ₂ BF ₄和（FAPbI ₃）的所有钙钛矿超晶格具有优异的光吸收性能，单结太阳能电池的计算功率转换效率为22.77％）获得了₃ / CsPbI ₂ BF ₄钙钛矿。