Enhanced structural, electronic, optical, elastic and mechanical properties of SrCeO3 with Mg and Th substitution for optoelectronic applications: A computational approach

The effects of different doping concentration of magnesium and thorium on structural, optoelectronics, and mechanical characteristics of SrCeO3 are investigated by using the Generalized gradient approximation, by Perdew Burke Ernzerhof, with ultra-soft pseudopotential in CASTEP code. Adding impurities at the two different sites (Sr-site and Ce-site) causes a considerable variation in the natural behavior of SrCeO3. A significant change in the bandgap from 2.266 eV to 0.503 eV is noticed and the phase transition from cubic to tetragonal is observed. The substitution of a small amount of dopant impacts the band structure of SrCeO3 and the density of states due to the emergence of new states of the dopant elements. Changes in electronic properties have an impact on the optical properties, which have been investigated and explained. Elastic constants of different doping concentrations have been calculated and all these satisfied the Born’s stability criteria. So, these crystal structures are mechanically stable except for the 7.04% and 9.85% of Mg-doped. The other mechanical properties including bulk, shear, Young’s moduli, Poisson ratio and Pugh ratio have been investigated to check whether the material is ductile or brittle. To check whether crystal is isotropic or anisotropic, we also calculated the anisotropic factor. The doped compound is the best candidate for optoelectronic applications.