First principles study of the electronic and optical properties of high‐valence transition metal‐doped anatase titanium dioxide

The formation energies and electronic and optical properties of anatase titanium dioxide doped with high‐valence transition metals (niobium, tantalum, tungsten, and molybdenum) were studied through first‐principles calculations based on density functional theory. The results showed that the doped titanium dioxide systems exhibited a typical n‐type metallic characteristic and high transmittance within the visible light spectrum. The high‐valence transition metal‐doped anatase titanium dioxide films should be formed under oxygen‐rich conditions and the niobium‐doped anatase titanium dioxide film is easier to synthesize and more stable than the other three films. Moreover, the band gaps of the doped titanium dioxide systems decrease due to the hybridization of transition metal d, tantalum 3d and oxygen 2p states. Niobium‐ and tantalum‐doped titanium dioxide have lower effective mass and higher electron mobility than tungsten‐ and molybdenum‐doped titanium dioxide, hence are more suitable for transparent conductive oxide materials.