材料化学组成对能带排列的影响：3D/2D钙钛矿界面的初步结果
Material chemical composition impacts on the band alignments: preliminary results on the 3D/2D perovskite interfaces
- EDF R&D, Department SYSTEME, EDF Lab Paris-Saclay（法国电力集团研发部，系统部门，巴黎萨克雷法国电力实验室）
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中文总结 AI 辅助
本研究通过第一性原理模拟，探究2D/3D钙钛矿界面的能带排列，发现功函数和能带偏移受表面化学和终止面显著影响，为钙钛矿稳定性优化提供理论依据。
中文摘要 AI 辅助
虽然杂化有机-无机卤化物钙钛矿太阳能电池已实现显著的认证效率，但其广泛的工业和社会的应用受到对光、热和湿气不稳定性的阻碍。缓解诸如湿气敏感性等问题的策略包括在3D薄膜上沉积2D钙钛矿以进行钝化，但其对电池性能的精确影响需要详细的理解。本工作采用基于杂化泛函的原子级第一性原理模拟，研究2D/3D界面的结构和电子性质。具体而言，它关注由(PEA)2PbI4（PEA = C6H5CH2CH2NH3，作为2D钙钛矿）和复杂3D钙钛矿（Cs0.125MA0.14FA0.735Pb(I0.87Br0.13)3，其中MA = CH3NH3，FA = CH(NH2)2）形成的界面，这些是最常用的钙钛矿之一。该方法基于优化的杂化泛函方法，以一致地确定不同层间的功函数（WF）、电子亲和势（___）和能带偏移（EBO）。初步结果表明，WF强烈依赖于表面的解理面和化学性质。此外，界面的形成显著影响宏观势，存在与3D材料因离子取代引起的极化相关的明显斜率。能带排列也对钙钛矿的终止面和化学性质高度敏感，价带和导带EBO分别变化0.2至0.7 eV和约0.25 eV。这项正在进行的工作旨在系统描述这些效应，并进一步研究维度损失对钙钛矿稳定性的影响。
英文摘要
While hybrid organic-inorganic halide perovskite solar cells have achieved remarkable certified efficiencies, their widespread industrial and societal adoption is hindered by instabilities against light, heat, and moisture. A strategy to mitigate issues, such as moisture sensitivity, involves depositing 2D perovskites on 3D thin films for passivation, but their precise impact on cell performance requires detailed understanding. This work employs atomistic first-principles simulation, based on hybrid functionals, to investigate the structural and electronic properties of 2D/3D interfaces. Specifically, it focuses on interfaces formed by (PEA)2PbI4 (PEA = C6H5CH2CH2NH3, as 2D perovskite) and complex 3D perovskites (Cs0.125MA0.14FA0.735Pb(I0.87Br0.13)3, with MA = CH3NH3 and FA = CH(NH2)2) which are ones of the most used perovskites. The approach is based on optimized hybrid functional methods to consistently determine work function (WF), electron affinity, and band offset (EBO) across different layers. Preliminary results demonstrate that WF are strongly dependent on the cleavage and chemical nature of the surfaces. Furthermore, the creation of interfaces significantly impacts macroscopic potential, with a noticeable slope linked to the polarization of the 3D materials due to ionic substitutions. The band alignment is also highly sensitive to the termination and chemical nature of the perovskites, with valence and conduction EBOs varying from 0.2 to 0.7 eV and of approximately 0.25 eV, respectively. This ongoing work aims to provide a systematic description of these effects, with further investigation into the impact of dimensionality loss on perovskite stability.
