First principle study of ATiO$$_3$$ (A=Ti,Sr) materials for photovoltaic applications

Abstract

Abstract Context The study investigates the impact of Hubbard U correction and spin-orbit coupling (SOC) on the structural, mechanical, electronic, and optical properties of Ti$$_2$$ 2 O$$_3$$ 3 and SrTiO$$_3$$ 3 compounds. The research is motivated by the potential applications of these materials in photovoltaics, with a focus on understanding their properties for such use. The ductility, ionicity, and mechanical stability of both compounds at zero pressure are assessed, indicating their potential as resilient materials. Also, the compounds display high refractive indices and absorption coefficients, indicating their suitability for solar harvesting applications. The predicted bandgaps align primarily with the UV–Vis areas of the electromagnetic spectrum, highlighting their potential in this domain. Methods Computational techniques employed in this study are density functional theory (DFT) with and without spin-orbit coupling, as well as DFT+U methods, implemented using the Quantum ESPRESSO (QE) package. The study adopts the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional, while employing a plane-wave basis set with an energy cutoff of 50 Ry for wavefunctions and 500 Ry for charge density.