Insight on Mg-doping dependent structural, electronic and optical properties of CaTiO3 for solar cell applications: A DFT study

We used first-principles density functional theory (DFT) computations to carefully study the structural, electrical, and optical characteristics of pure and Mg-doped CaTiO₃. In contrast to prior studies that concentrated on the dielectric or surface properties of CaTiO₃, the current research investigates the microscopic process by which Mg substitution alters the band structure and optical response pertinent to solar energy conversion. Our findings indicate that the addition of Mg results in a marginal decrease in both lattice parameters and bond lengths, alongside an increase in the electronic band gap from 1.85 to 2.05 eV, signifying a blue shift advantageous for solar cell performance. The movement of the Fermi level into the valence band and the changes in the partial density of states show how strongly Mg affects the electrical structure of CaTiO₃. The optical absorption edge also moves closer to the visible region, which suggests that the optoelectronic response is better. This study offers novel theoretical perspectives on band gap engineering via Mg doping in CaTiO₃ and illustrates its viability as a cost-effective and eco-friendly material for next-generation solar and optoelectronic devices.