Restrained by the difficulties in the stability, crystal processing, and single-crystalline device fabrication based on the prototype perovskite of CH₃NH₃PbI₃, there is a growing interest in finding a way to introduce long-chain organic ammonium into CH₃NH₃PbI₃ to tackle these challenges, leading to emerging layered perovskite materials. Here, we first report the bulk crystal growth in an ambient atmosphere on single crystals of layered perovskite (n-C₄H₉NH₃)₂(CH₃NH₃)_n−1Pb_nI_3n+1 (n = 1, 3, and 4) obtained using fine control of the molar ratio of perovskite precursors by the top seeded solution growth (TSSG) method. The fundamental properties (band gap, PL spectra and thermal stability) of (n-C₄H₉NH₃)₂(CH₃NH₃)_n−1Pb_nI_3n+1 (n = 1, 3, and 4) single crystals are investigated. More importantly, we investigated the formation of (n-C₄H₉NH₃)₂(CH₃NH₃)_n−1Pb_nI_3n+1 (n = 3 and 4) thin films based on their single-crystalline precursors by a modified hot-casting method, which makes it easier to obtain uniformly oriented thin films to help improve the photovoltaic performance and reproducibility. And solar cells fabricated based on these thin films exhibited a power conversion efficiency (PCE) of 5.05% (n = 3) and 9.03% (n = 4), and demonstrated good feasibility and stability. These attractive results may provide an understanding for further studies of the optoelectronic device applications of these layered perovskite materials.

中文翻译：

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基于单晶前体解决方案的层状混合钙钛矿太阳能电池，具有出色的可重复性†

受制于基于CH ₃ NH ₃ PbI ₃原型钙钛矿的稳定性，晶体加工和单晶器件制造方面的困难，对寻找将长链有机铵引入CH ₃ NH的方法的兴趣与日俱增₃ PbI ₃应对这些挑战，导致出现层状钙钛矿材料。在这里，我们首先报告在环境大气中层状钙钛矿（n -C ₄ H ₉ NH ₃）₂（CH ₃ NH ₃）_{n -1的}单晶上的晶体生长Pb _n I _{3 n +1}（n = 1、3和4）是通过顶部种子溶液生长（TSSG）方法精细控制钙钛矿前体的摩尔比而获得的。（n -C ₄ H ₉ NH ₃）₂（CH ₃ NH ₃）_{n -1} Pb _n I _{3 n +1}（n = 1、3和4 ）的基本性质（带隙，PL光谱和热稳定性））研究了单晶。更重要的是，我们研究了（n -C ₄ H₉ NH ₃） ₂（CH ₃ NH ₃） _{n -1} Pb _n I _{3 n +1}（ n = 3和4）薄膜，基于它们的单晶前驱体，采用改进的热浇铸法，使其更易于制造获得均匀取向的薄膜，以帮助提高光伏性能和可重复性。基于这些薄膜制造的太阳能电池的功率转换效率（PCE）为5.05％（ n = 3）和9.03％（ n= 4），并显示出良好的可行性和稳定性。这些诱人的结果可以为进一步研究这些层状钙钛矿材料的光电器件应用提供理解。