First-principles study on structural and electronic properties of Er-doped dysprosium orthovanadate oxide

Comprehensive structural and electronic properties of zircon-type ternary-metal oxide, dysprosium orthovanadate, doped with varying concentrations of Er have been investigated using first-principles density functional theory (DFT). Furthermore, the significance of substitutional site doping has been elucidated, revealing that Er incorporation can profoundly alter the structural and electronic characteristics of DyVO₄. Replacing Er atoms with Dy atoms through substitutional doping reduces the band gap to 2.79 eV compared to the pure zircon-type dysprosium vanadate oxide's band gap value of 2.87 eV. Cohesive energy of Er-doped DyVO₄ oxide has also been computed at the ab initio level of calculation. Partial density of states' (PDOS) calculations of all configurations, suggest that the doping element Er exhibits favourable chemical interactions with the host metal oxide, DyVO₄. Electronic bands near the zero-energy or Fermi level strongly originate from the molecular orbitals of O, V and Dy atoms. Still, we have found that cation substitution at Dy ions' site largely influences these electronic states and decreases band gap energy value. Consequently, by adjusting concentration of the dopant, the band gap of DyVO₄ oxide can be finely tuned to achieve specific desired levels, which is suitable for electronic applications. (author)