Temperature and composition dependence of the band gaps of Ga$_{1-x}$In$_x$N alloy: a first-principles study based on the virtual crystal approximation
本文采用第一性原理的虚晶近似（VCA）方法研究了Ga $_{1-x}$ In $_x$ N合金的结构、电子和振动性质。用TB 09泛函获得了3.85 eV的带隙弯曲参数。声子态密度随着In含量的增加向低频移动。然而，VCA忽略了无序效应，因此无法描述合金化后声子谱的展宽。本文还研究了GAN、InN及其合金Ga $_{1-x}$ In $_x$ N的电子-声子相互作用对带隙温度依赖性的影响。计算的零点运动重整化和拟合的Varshni参数在整个组成范围内进行了讨论。
英文摘要：
We report on the structural, electronic and vibrational properties of the Ga$_{1-x}$In$_x$N alloy using virtual crystal approximation (VCA) from first-principles. A band gap bowing parameter of 3.85 eV is obtained with the TB09 functional. Phonon density of states shifts to lower frequency as the In content is increased. However, VCA ignores disorder effect and is therefore unable to describe the broadening of the phonon spectra upon alloying. The role of electron-phonon interaction in the temperature dependence of the band gap is also studied for GaN, InN and their alloy Ga$_{1-x}$In$_x$N. The calculated zero-point motion renormalization and the fitted Varshni parameter over the entire composition range are discussed.
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High-dielectric constant and wide band gap inverse silver oxide phases of the ordered ternary alloys of SiO$_{2}$, GeO$_{2}$ and SnO$_{2}$
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The band gap engineering of group IV semiconductors has not been well explored theoretically and experimentally, except for SiGe. Recently, GeSn has attracted much attention due to the possibility of obtaining a direct band gap in this alloy, thereby making it suitable for light emitters. Other group IV alloys may also potentially exhibit material properties useful for device applications, expanding the space for band gap engineering in group IV. In this work the electronic band structure of all group IV semiconductor alloys is investigated. Twelve possible A:B alloys, where A is a semiconduct…
