Abstract Silver gallium telluride AgGaTe2 is a promising and one of few multifunctional energy convertor crystal for processing solar energy or waste heat into electricity (by the thermoelectric, photovoltaic and recently intensively studied thermophotovoltaic systems). Its electronic structure, optical, elastic and vibrational properties were consistently and systematically studied in the framework of the first principles calculations. It should be emphasized that the results of our investigations were verified by comparison with the collected available experimental and vestigial theoretical data. The main spectral features of the electronic band structure and origin of the electronic levels affecting the physical and chemical properties are analyzed in detail. Spectral dependencies of both real e1 and imaginary e2 components of dielectric function e(ω) have been calculated showing a good agreement with spectral ellipsometry measurements. The anisotropy of optical and elastic properties, which is important for possible applications, has been highlighted by means of the 2D and 3D graphs. Phonon dispersion curves and corresponding density of states are studied in the frame of linear response approach based on the density functional perturbation theory. Unified approach focused on the analysis of a wide-range physical properties of anisotropic crystals not only results in good agreement with the experimental data, but also allows to explain the observed optical effects at the microscopic level. Therefore, the presented results should be very useful for future possible improvements in the desired properties of the base material both by changing the chemical composition and/or introducing stresses by epitaxial growth of thin films.

中文翻译：

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AgGaTe2 - 热电和太阳能电池材料：结构、电子、光学、弹性和振动特性

摘要 碲化银镓AgGaTe2 是一种很有前途的多功能能量转换晶体之一，用于将太阳能或废热转化为电能（通过热电、光伏和最近深入研究的热光伏系统）。它的电子结构、光学、弹性和振动特性在第一性原理计算的框架内得到了一致和系统的研究。应该强调的是，通过与收集到的可用实验和残余理论数据进行比较，我们的调查结果得到了验证。详细分析了电子能带结构的主要光谱特征和影响物理化学性质的电子能级的来源。已经计算出介电函数 e(ω) 的实部 e1 和虚部 e2 分量的光谱相关性，显示出与光谱椭偏测量的良好一致性。光学和弹性特性的各向异性对可能的应用很重要，已通过 2D 和 3D 图形突出显示。在基于密度泛函微扰理论的线性响应方法框架内研究了声子色散曲线和相应的态密度。统一方法专注于分析各向异性晶体的广泛物理特性，不仅与实验数据具有良好的一致性，而且还可以在微观层面解释观察到的光学效应。所以，