We have used the periodic quantum-mechanical method with density functional theory at the B3LYP hybrid
functional level in order to study the doping of SnO2 with pentavalent Sb5+. The 72-atom 2x3x2 supercell SnO2 (Sn24O48)
was employed in the calculations. For the SnO2:4%Sb , one atom of Sn was replaced by one Sb atom. For the SnO2:8%Sb,
two atoms of Sn were replaced by two Sb atoms. The Sb doping leads to an enhancement in the electrical conductivity of
this material, because these ions substitute Sn4+ in the SnO2 matrix, leading to an electronic density rise in the conduction
band, due to the donor-like behavior of the doping atom. This result shows that the bandgap magnitude depends on the
doping concentration, because the energy value found for SnO2:4%Sb was 2.8eV whereas for SnO2:8%Sb it was 2.7eV. It
was also verified that the difference between the Fermi level and the bottom of the conduction band is directly related to
the doping concentration.
Keywords: Bandgap, DFT, fermi Level, t in dioxide.
Rights & PermissionsPrintExport