Article ID Journal Published Year Pages File Type
10714006 Physica B: Condensed Matter 2012 6 Pages PDF
Abstract
The electronic structures and optical properties of N-doped, S-doped and N/S co-doped SrTiO3 have been investigated on the basis of density functional theory (DFT) calculations. Through band structure calculation, the top of the valence band is made up of the O 2p states for the pure SrTiO3. When N and S atoms were introduced into SrTiO3 lattice at O site, the electronic structure analysis shows that the doping of N and S atoms could substantially lower the band gap of SrTiO3 by the presence of an impurity state of N 2p on the upper edge of the valence band and S 2p states hybrid with O 2p states, respectively. When the N/S co-doped, the energy gap has further narrowing compared with only N or S doped SrTiO3. The calculations of optical properties also indicate a high photo response for visible light for N/S co-doped SrTiO3. Besides, we find a new impurity state which separates from the O 2p states could improve the photocatalytic efficiency and we also propose a model for light electron-hole transportation which can explain the experiment results well. All these conclusions are in agreement with the recent experimental results.
Related Topics
Physical Sciences and Engineering Physics and Astronomy Condensed Matter Physics
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