Structural and electronic properties of CaTiO3 polymorphs and 2D-derived systems: a theoretical investigation

Abstract

Oxide perovskite materials exhibit intriguing optical and electrical properties that are widely exploited in ceramics and optoelectronic devices. With particular emphasis on its application for photocatalysis, this study aims to theoretically characterize the structural and electronic features of CaTiO₃, both as a stand-alone material and as a possible component in heterostructures. By means of a campaign of ab-initio calculations, we have revised the polymorphic nature of the material through an extensive analysis of its structural and electronic properties. Although standard DFT clearly confirms its intrinsic underestimation in predicting the excited state properties, by applying the recently introduced DFT\(-\frac{1}{2}\) method to the bandgap and dispersion calculations, we find very good agreement with experimental reported data. Finally, we include the investigation of dimensionally reduced CaTiO₃-based surfaces and nanosheets, opening the way to interesting possibilities for additional novel supports and photocatalysts with unique features.