Zirconium-based cubic-perovskite materials for photocatalytic solar cell applications: a DFT study

The structural, electronic, optical, and mechanical characteristics of the cubic inorganic perovskites XZrO3 (X = Rb and K) based on Rb and K were studied using Cambridge Serial Total Energy Package (CASTEP)-based density functional theory (DFT) via the ultrasoft pseudo-potential (USP) plane wave and generalized gradient approximation (GGA)-Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional. The measured lattice parameters are 3.55 Å and 4.23 Å, and the band gaps of RbZrO3 and KZrO3 are 3.57 eV and 3.78 eV, respectively. Our results indicate that the compounds have indirect and wide bandgaps, making them useful for improving conductivity. It is observed that the compounds have anisotropic, ductile, and brittle natures. The anisotropic factor values of RbZrO3 and KZrO3 are 0.67067 and 0.87224, and their Poisson's ratios are 0.27356 and 0.25853, respectively. In terms of optical properties, they exhibited high optical absorption and conductivity and were active in the visible region for solar cell applications. These results indicate that they could be highly useful for light-emitting diodes (LEDs) and other reflection purposes owing to their indirect bandgap. The results of our investigation of RbZrO3 and KZrO3 present them as favorable materials for solar cell and LED applications.