Abstract

In this work, the structural and electronic properties of the ternary chalcopyrite semiconductors ZnSiAs₂ and ZnSnAs₂ and their related ZnSi_{1 – x}Sn_xAs₂ quaternary alloys are presented. The density functional theory (DFT) within full-potential linearized augmented plane wave is employed. To treat the exchange–correlation potential for the total energy calculations, the generalized gradient approximation by Wu–Cohen is used. Additionally, the modified Becke–Johnson potential approximation has also been used to improve the underestimated band gap. For the ternary compounds, the optimized equilibrium structural parameters (a, c, and u) are in good agreement with available theoretical and experimental data. ZnSi_{1 – x}Sn_xAs₂ alloys are direct band gap semiconductors. The effects of the composition x on lattice parameters, bulk modulus, and band gaps are investigated. A quadratic fit of the lattice parameter, bulk modulus, and band gap is performed, where a non-linear variation with the composition is found. A decrease in the band gap is observed with an increasing Sn content.

中文翻译：

---

ZnSiAs 2，ZnSnAs 2及其混合晶体ZnSi 1-x Sn x As 2的结构和电子性质

摘要

在这项工作中，提出了三元黄铜矿半导体ZnSiAs ₂和ZnSnAs ₂及其相关的ZnSi _{1- x} Sn _x As ₂四元合金的结构和电子性能。采用全势线性化增强平面波内的密度泛函理论（DFT）。为了处理总能量计算中的交换相关势，使用了Wu-Cohen的广义梯度近似。此外，修改后的Becke-Johnson势近似也已用于改善被低估的带隙。对于三元化合物，优化的平衡结构参数（a，c和u）与可用的理论和实验数据高度吻合。ZnSi _{1 – x} Sn _x As ₂合金是直接带隙半导体。研究了组成x对晶格参数，体积模量和带隙的影响。执行晶格参数，体积模量和带隙的二次拟合，在其中发现组成的非线性变化。随着Sn含量的增加，带隙减小。