First-principles analysis of novel Mg-based group II-VI materials for advanced optoelectronics devices

Abstract

Here, in this work, the structural, electronic, optical, and transport properties of Magnesium-based group II-VI materials are studied by employing the density functional theory calculations. The WC-GGA and EV-GGA generalized gradient approximations were employed to compute the structure parameters along with the electronic nature of the ternary-type materials. Our calculations confirmed the materials to be indirect band-type semiconductors with a bandgap value of 1.17 ​eV, and 0.51 ​eV, for the MgCdO2 and MgCdS2 materials respectively. Since Sulfur has a larger atomic radius than Oxygen, the bandgap value declines in going from MgCdO2 to MgCdS2 material. The computed total density of states for these materials displayed a sequential shift with increasing energy. The linear optical parameters like the real and imaginary parts of the dielectric function, the energy loss function, the absorption coefficient, the reflectivity, and the refractive index values are calculated and analyzed in detail. Moreover, the thermoelectric properties were also computed, and the results are presented in depth, suggesting all these materials to be efficient for thermoelectric device applications.