Tuning the optical properties through bandgap engineering in Si-doped YAuPb: ab initio study

In order to probe the bandgap engineering to tune optical properties in YAuPb1−xSix (x = 0, 0.25, 0.50, 0.75 and 1) alloys, we used all-electron full-potential linearized augmented plane wave (FP-LAPW+lo) method within the framework of the density functional theory. The optimized structural parameters were in good agreement with other theoretical and experimental results. The calculated results of elastic constant satisfy the condition for mechanical stability at each composition for cubic symmetry. In addition, the study of elastic parameters is summarized for the calculation bulk modulus, Young’s modulus, shear modulus, Kleinman parameters, Poisson’s ratio and Lame’s co-efficient. To predict the brittle (ductile) nature of this composition, the Cauchy pressure, Poisson’s ratio, and B/G ratio were also calculated. Using modified Becke and Johnson GGA, the bandgap values of each composition were computed precisely. Further, it was observed that for 0.25 < x < 0.75, the bandgap structure revealed a direct bandgap configuration. In order to analyze the electronic structure of each composition, the total and partial densities of states have been investigated in detail. Furthermore, the investigation of optical parameters in terms of dielectric functions revealed the potential of these alloys for optoelectronic devices.