Quasi-two-dimensional (Q-2D) perovskite solar cells have garnered significant attention due to their unique hydrophobic organic cations and commendable stability. However, there is currently no established set of criteria for selecting the appropriate organic cations to fabricate highly efficient and stable Q-2D perovskite solar cells. This work systematically examines the organic interstitial cations containing fluorine atoms at various substitution positions in phenylmethylamine, focusing on crystal orientation, film morphology, and the photoelectric conversion efficiency (PCE) of n = 5 perovskite films. Through density functional theory (DFT) calculations and crystal structure analysis, it is revealed that compared to PMA-F, oFPMA-F and mFPMA-F, pFPMA-F exhibits the largest dipole moment. Additionally, (pFPMA)₂PbI₄ demonstrates a larger effective mass and greater layer spacing compared to (PMA)₂PbI₄. The findings revealed that in comparison to PMA-F, oFPMA-F and mFPMA-F, the pFPMA-F 2D perovskite film exhibits a preferential in-plane orientation, superior crystallinity, and higher carrier mobility. Consequently, the Q-2D perovskite solar cell device utilizing pFPMA-F achieved a PCE of 15.88%, which markedly surpassed those of the PMA-F (9.15%), oFPMA-F (12.62%), and mFPMA-F (7.8%) counterparts. Additionally, the device architecture based on pFPMA-F demonstrated exceptional stability.

中文翻译：

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不同取代位点的氟化苄胺基团制备高性能准二维 （Q-2D） 钙钛矿太阳能电池


准二维 （Q-2D） 钙钛矿太阳能电池因其独特的疏水性有机阳离子和值得称赞的稳定性而受到广泛关注。然而，目前还没有一套既定的标准来选择合适的有机阳离子来制造高效和稳定的 Q-2D 钙钛矿太阳能电池。这项工作系统地研究了苯甲胺中不同取代位点含有氟原子的有机间隙阳离子，重点研究了 n = 5 钙钛矿薄膜的晶体取向、薄膜形貌和光电转换效率 （PCE）。通过密度泛函理论 （DFT） 计算和晶体结构分析，发现与 PMA-F、oFPMA-F 和 mFPMA-F 相比，pFPMA-F 表现出最大的偶极矩。此外，与 （PMA）₂PbI₄ 相比，（pFPMA）₂PbI₄ 表现出更大的有效质量和更大的层间距。研究结果表明，与 PMA-F、oFPMA-F 和 mFPMA-F 相比，pFPMA-F 2D 钙钛矿薄膜表现出优先的面内取向、优异的结晶度和更高的载流子迁移率。因此，使用 pFPMA-F 的 Q-2D 钙钛矿太阳能电池器件实现了 15.88% 的 PCE，明显超过了 PMA-F （9.15%）、oFPMA-F （12.62%） 和 mFPMA-F （7.8%） 同类产品。此外，基于 pFPMA-F 的器件架构表现出卓越的稳定性。