DFT+U studies of structure and optoelectronic properties of Fe2SiO4 spinel

Spinel oxides have been predicted as one of the potential materials in the transparent conducting oxides community. A detailed first-principles pseudopotential investigation was performed with a view to explain the structure and optoelectronic properties of Fe2SiO4 spinel. The band structure of Fe2SiO4 spinel without Coulomb Parameter U shows that the bands close to Fermi energy appear to be a band metal, even though experimentally it was found to be an insulator. Our result also reveals that the n-type Fe2SiO4 would be more useful for optoelectronic devices performance than that of p-type and the electrical conductivity charge concentration by valence energy band electrons is more desirable than that by conduction band holes. Further, we have shown that the dispersion together with the character of the conduction bands is part of the important features of the band structure controlling the optoelectronic application. •First-principles investigation of the structural and optoelectronic properties for bulk Fe2SiO4 spinel.•DFT + U method is used to find more accurate band gap.•The electronic properties exhibit a direct band gap for Fe2SiO4 spinel.•The interband electronic transitions are investigated by band structure.•Fe2SiO4 spinel shows different properties and is more suitable for optoelectronic applications.