Two-dimensional (2D) halide-based hybrid perovskites are recognized as emerging materials for solar cells and thermoelectric applications. Here, we report on the electronic, optical, and thermoelectric properties of the 2-(methylthio)ethylamine (MTEA)-based 2D perovskites (MTEA)₂PbI₄ and (MTEA)₂(MA)Pb₂I₇ using density functional theory calculations. The Rashba-splitting strength is observed to lie between 0.41 and 0.65 eV Å at four positions of the band structure of (MTEA)₂(MA)Pb₂I₇. The strong sulfur–sulfur interaction between MTEA spacers results in a noticeable shift in the onset of the absorption spectrum. For (MTEA)₂(MA)Pb₂I₇, a larger theoretical limit in the power conversion efficiency (29%) is calculated compared to (MTEA)₂PbI₄, which can be attributed to the absorption coefficient difference in both structures. The considered structures show very small effective electron masses, which results in an exceptionally high electron carrier mobility. The calculations yield an extremely large thermoelectric power factor of 42.3 mW/mK² for (MTEA)₂(MA)Pb₂I₇ at 300 K, which is even higher than that of 3D and 2D perovskites reported so far. The present work suggests that the (MTEA)-based 2D perovskites are promising candidates for application in solar- and thermal-energy harvesting.

中文翻译：

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二维卤化物钙钛矿材料具有 2-(甲硫基) 乙胺有机间隔物，用于高效的太阳能和热能收集

二维 (2D) 卤化物基杂化钙钛矿被认为是太阳能电池和热电应用的新兴材料。在这里，我们使用密度泛函理论报告了基于 2-(甲硫基)乙胺 (MTEA) 的二维钙钛矿 (MTEA) ₂ PbI ₄和 (MTEA) ₂ (MA)Pb ₂ I ₇的电子、光学和热电特性计算。_{在 (MTEA) 2} (MA)Pb ₂ I ₇的能带结构的四个位置，观察到 Rashba 分裂强度介于 0.41 和 0.65 eV Å 之间。MTEA 间隔物之间​​强烈的硫-硫相互作用导致吸收光谱开始时发生明显变化。对于 (MTEA)₂ (MA)Pb ₂ I _{7与(MTEA) 2} PbI ₄相比，计算出功率转换效率的更大理论极限(29%) ，这可归因于两种结构中的吸收系数差异。所考虑的结构显示出非常小的有效电子质量，这导致了异常高的电子载流子迁移率。计算得出(MTEA) ₂ (MA)Pb ₂ I ₇的极大热电功率因数 42.3 mW/mK ²在 300 K，甚至高于迄今为止报道的 3D 和 2D 钙钛矿。目前的工作表明，基于 (MTEA) 的二维钙钛矿有望应用于太阳能和热能收集。