Computational and experimental study of Ta₂O₅ thin films

This paper reports the novel synthesis of amorphous Ta₂O₅ and the subsequent isolation of the orthorhombic (β) crystallographic phase, using aerosolassisted chemical vapor deposition. Hybrid density functional theory was used to obtain the calculated optical band gap (3.83 eV) for the first time, which closely matches our experimental findings (3.85 eV). The films were highly transparent in the visible and near-IR region of the electromagnetic spectrum. The refractive indexes, calculated using the Swanepoel method, showed good agreement with literature findings. The photocatalytic properties of the films, determined through the photominerilization of stearic acid under 254 nm radiation showed the amorphous sample to be an order of magnitude superior over crystalline β-Ta₂O₅.