Tuning the electronic and optical properties of BaNiO3 via Fe substitution: a first-principles study

Abstract

The hexagonal BaNiO3 is a novel ferroelectric material for potential photovoltaic applications. The literature about the electronic and optical properties for the BaNiO3 is scarce. This study, based on density functional theory calculations, demonstrates that with Ni-site elemental substitution, the hexagonal BaNiO3 can exhibit a much lower fundamental band gap than that of the pristine material. Cation atomic size and electronegativity, are evidenced as critical parameters to tailor the metal 3d-oxygen 2p orbital interactions and thus intrinsically modify the electronic structure, particularly the shape and character of the valence and conduction band edges. With the reduced band gap and uncompromised ferroelectric and magnetic ground states, the present results provide a new strategy to design the BaNiO3 for efficient optoelectronic applications.