Theoretical investigation of the structural, electronic, optical, and elastic properties of the zinc blende SiGe1-xSnx ternary alloy

The physical and chemical features of the SiGe1 - xSnx ternary alloy structured in cubic phase are investigated. Three distinct approaches (PBE-GGA), (PW-LDA), and (PW-LDA) are used to compute the structural characteristics such as the lattice constants a, the bulk modulus B and its first pressure derivative B'. Alongside the PBE-GGA method, we utilized the recently introduced (TB-mBJ) approach incorporating spin-orbit coupling (SO) to analyze the electronic properties (band structure as well as density of states (DOS)) for the investigated materials. Additionally, for providing a more precise understanding of the alloys' electrical characteristics. By varying the tin composition from 0 to 1 by 0.25 steps, the optical characteristics of the studied materials are also evaluated with TB-mBJ + SO. The ternary alloys SiGe0.75Sn0.25, SiGe0.5Sn0.5, and SiGe0.25Sn0.75 are direct bandgap semiconductors while the binary compounds SiGe and SiSn are indirect bandgap semiconductors. The main Tomas Charpin's model is used to compute the elastic characteristics of ternary alloys with their binary constituents. Except for the binary compounds SiGe and SiSn, the other ternary alloy results are scarce.