Abstract

The structural, electronic, optical and thermodynamic properties of Cs₃Sb₂I₉ compound with 0-D dimer form (hexagonal SP; P63∕mmc, no. 194) and the 2-D layered form (trigonal SP; P3m̄1, no. 164) phases have been investigated and reported using both FP-LAPW and PP-PW methods. Besides, the thermodynamic properties of the materials of interest have been studied using the quasi-harmonic Debye model accommodating the lattice vibrations effects. The obtained lattice parameters for dimer and layered phase reveal very good accord with experiment. The computed electronic band structures show that in the dimer phase the material of interest is an indirect band-gap (k–Γ) semiconductor, whereas it is a direct band-gap (Γ–Γ) in the layered phase. The semiconducting material Cs₃Sb₂I₉ of interest was found to be stable against volume change of 0 to +14%. Moreover, the optical properties of the material in question are also examined and discussed. The effect of pressure and temperature on the studied properties is found to be highly effective in tuning some of the macroscopic properties of the compound in question.

Graphical abstract

中文翻译：

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三角和六方Cs 3 Sb 2 I 9化合物的结构，电子，光学和热力学性质的理论分析

摘要

Cs的结构，电子，光学和热力学性质₃的Sb ₂我₉（;六边形SP与0-d二聚体形式化合物P 63 / MMC，无194）和2-d层状形式（三角SP; P3中号1 （第164号）阶段已使用FP-LAPW和PP-PW方法进行了调查和报告。此外，已使用适应晶格振动效应的准谐波德拜模型研究了目标材料的热力学性质。得到的二聚体和层状相的晶格参数与实验结果非常吻合。计算得出的电子能带结构表明，在二聚体相中，所关注的材料是间接带隙（k-Γ）半导体，而它是分层相中的直接带隙（Γ-Γ）。发现所关注的半导体材料Cs ₃ Sb ₂ I ₉对于0至+ 14％的体积变化是稳定的。此外，还研究和讨论了所讨论材料的光学性质。发现压力和温度对所研究性质的影响在调节所讨论化合物的某些宏观性质方面非常有效。

图形概要