Ab-initio calculation of the structural, electronic, mechanical, optical, and thermoelectric properties of orthorhombic ZnAs compound

First-principles calculations of the structural, electronic, elastic, optical, and thermoelectric properties of the ZnAs compound have been investigated using density functional theory (DFT). To figure out the structural and mechanical properties, we used the generalized gradient approximation of Perdew-Bruke-Ernzerhof (PBE-GGA). Our computed structural properties are closely aligned with experimental values. The elastic constants have verified the mechanical stability of the ZnAs compound and also showed that the latter is stiff and brittle, confirming its semiconducting behavior. Furthermore, we used the modified Beck and Johnson (TB-mBJ) potential to study the band structure and density of state, which revealed that ZnAs is a semiconductor compound with an indirect band gap. The optical characteristics of ZnAs show that it can be used as a candidate for optoelectronics since it has high optical conductivity. Finally, our compound is a good thermoelectric material with a high-power factor and a figure of merit close to unity (0.98 at 300 K and 0.91 at 1000 K).