First-principles calculations of electronic and optical properties of Ti-doped monoclinic HfO2

Based on the first-principles density-functional theory, the electronic structures and optical properties of monoclinic HfO2 and Ti-doped m-HfO2 are comparatively investigated. The calculated lattice parameters of m-HfO2 are in good agreement with the experimental values and the previous works, and the incorporation of Ti into HfO2 induces a decrease in the lattice parameters. Electronic structures of m-HfO2 and Ti-doped HfO2 are studied through the densities of states (DOS) and band structures. The results indicate that the Ti substitution of Hf sites modifies the conduction band structure of HfO2, which leads to a reduction of the band gap of HfO2. The complex dielectric function and refractive index are calculated and the peak position distributions of imaginary parts of the complex dielectric function have been explained. The calculated optical properties are consistent with the experimental measurements for m-HfO2.

► The lattice constants of Ti-doped HfO2 are calculated. ► The addition of Ti modifies the conduction band structure of m-HfO2. ► Optical properties of Ti-doped HfO2 are calculated.