Ab-initio investigation of AGeO₃ (A = Mg, Cd) perovskites: structural, elastic, and optoelectronic properties

Herein, we investigated the physical properties of AGeO₃ (A = Mg, Cd) using the WIEN2k package within the framework of density functional theory. Structural analysis validated the stability of these perovskites by confirming that they crystallize in a cubic structure with the space group pm-3m (#221). By employing Poisson’s ratio and the Pugh criterion, CdGeO₃ was found to exhibit ductile behavior, while MgGeO₃ is brittle. The electronic properties were assessed through computation of the band profiles and the density of states. Our mBJ calculations revealed the semiconducting nature of the material, with an indirect bandgap (M– Γ) of 3.2/2.3 eV for MGeO₃/CdGeO₃. Furthermore, the outcomes concerning the total and partial density of states validated the degree of electron localization within specific bands. The optical behavior of the title compounds was investigated by computing the complex dielectric function, absorption coefficient, extinction coefficient, refractive index, optical conductivity, reflectivity, and energy loss function for the energy spectrum spanning from 0 to 40 eV. Our findings indicate the encouraging prospects of the studied compounds for use in optoelectronic devices.