Unravelling the correlated electronic and optical properties of BaTaO2N with perovskite-type structure as a potential candidate for solar energy conversion.

We report on the first principles calculation of the electronic, structural and optical properties of BaTaO2N, using density functional theory (DFT) and finite difference time domain (FDTD) methods. Band structure calculations were performed to calculate the direct and indirect bandgaps of the material. Density of states and Mulliken charge analysis as well as the electronic contour maps were established to determine the type of bonding and hybridization between the various electronic states. The dielectric constant, reflectivity, absorption, optical conductivity and energy-loss function were also calculated. Moreover, FDTD was used to investigate the optical properties of a larger and more reliable structure of BaTaO2N powder in good agreement with the reported experimental parameters. The calculated electronic, structural and optical properties showed the potential of BaTaO2N for solar energy conversion and optoelectronic applications.