Structural, electronic and optical properties of S-doped, Sc-doped and Sc–S co-doped anatase TiO2: a DFT + U calculation★
Department of Physics, East China Jiaotong University,
330013, P.R. China
2 Spallation Neutron Source Science Center, Institute of High Energy Physics, Chinese Academy of Sciences, Dongguan 523803, P.R. China
a e-mail: email@example.com
Received in final form: 10 September 2020
Accepted: 14 September 2020
Published online: 4 November 2020
Defect formation energies, electronic structures and optical properties of non-metal S, lanthanide metal Sc-doped and Sc–S co-doped anatase TiO2 were systematically investigated via a GGA + U method based on density functional theory (DFT). The on-site Coulomb corrections were applied to both 3d orbitals of Ti atom (UTi_3d) and 2p orbitals of O atom (UO_2p). The results show all doped TiO2 systems exhibit a certain degree of red-shift due to the presence of impurity levels in the bandgap; in particular, the S-doped and Sc–S co-doped TiO2 exhibit better light absorption properties in the visible light range than either pure or Sc-doped TiO2. In addition, the positive synergistic effect between the Sc and S atoms not only expands the absorption edge, but also increases the light absorption coefficient in the visible region. As a result, the Sc–S co-doped anatase TiO2 shows the best optical absorption spectrum in all doping systems.
Key words: Solid State and Materials
Supplementary material in the form of one pdf file available from the Journal web page at https://doi.org/10.1140/epjb/e2020-10368-x.
© EDP Sciences / Società Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020