Band gap engineering of early transition-metal-doped anatase TiO2: first principles calculations

Abstract

The thermal stability and electronic structures of anatase TiO₂ doped with early transition metals (TM) (group III-B = Sc, Y and La; group IV-B = Zr and Hf; group V-B = V, Nb and Ta) have been studied using first principles calculations. It was found that all doped systems are thermodynamically stable, and their band gaps were reduced by 1–1.3 eV compared to pure TiO₂. Doping with transition metals affects the strength of the hybrid orbital of TM–O bonding, and the band gap increases approximately linearly with the MP value of TM–O bonding.