arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2407.03437cond-mat.mtrl-sci
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基于第一性原理计算的CsSnI$_3$表面相图

Surface phase diagram of CsSnI$_3$ from first-principles calculations

Kejia Li, Chadawan Khamdang, Mengen Wang

AI总结:

本文通过第一性原理计算构建CsSnI$_3$三个低指数表面的相图,发现贫I条件下化学计量比(100)表面无表面态且最稳定,有利于提升光电器件性能。

摘要:

CsSnI$_3$作为一种环境友好的无铅钙钛矿材料,在光电器件应用中被广泛研究。为了进一步提升材料和器件性能,理解CsSnI$_3$的表面结构至关重要。我们生成了具有不同化学计量比的表面结构,通过密度泛函理论计算构建了CsSnI$_3$ (001)、(110)和(100)表面的相图,并确定了在广泛的Cs、Sn和I化学势范围内最稳定的表面。在富I条件下,具有Cs空位的表面是稳定的,这导致在价带顶上方出现部分占据的表面态。在贫I条件下,我们发现化学计量比的(100)表面在相图的广泛区域内是稳定的,该表面没有任何表面态,有助于延长电荷载流子寿命。因此,贫I(富Sn)条件将更有利于改善器件性能。

英文摘要:

CsSnI$_3$ is widely studied as an environmentally friendly Pb-free perovskite material for optoelectronic device applications. To further improve material and device performance, it is important to understand the surface structures of CsSnI$_3$. We generate surface structures with various stoichiometries, perform density functional theory calculations to create phase diagrams of the CsSnI$_3$ (001), (110), and (100) surfaces, and determine the most stable surfaces under a wide range of Cs, Sn, and I chemical potentials. Under I-rich conditions, surfaces with Cs vacancies are stable, which lead to partially occupied surface states above the valence band maximum. Under I-poor conditions, we find the stoichiometric (100) surface to be stable under a wide region of the phase diagram, which does not have any surface states and can contribute to long charge carrier lifetimes. Consequently, the I-poor (Sn-rich) conditions will be more beneficial to improve the device performance.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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