Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (03): 751-757.doi: 10.3866/PKU.WHXB20100215


Effect of In and Sc Doping on the Electronic Structure and Optical Properties of SrTiO3

YUN Jiang-Ni, ZHANG Zhi-Yong   

  1. School of Information Science and Technology, Northwest University, Xi'an 710127, P. R. China
  • Received:2009-08-19 Revised:2009-12-01 Published:2010-03-03
  • Contact: ZHANG Zhi-Yong


The effect of In and Sc p-type doping on the structural stability, electronic structure, and optical properties of SrTiO3 was investigated by first-principles calculations of plane wave ultra-soft pseudo-potential based on density functional theory (DFT). The calculated results revealed that the structural stability of SrTiO3 was weakened after In and Sc doping and that the partial substitution of In for Ti (or Sc for Ti) merely resulted in local structural changes around the dopant sites. The doped SrIn0.125Ti0.875O3 and SrSc0.125Ti0.875O3 systems are p-type degenerate semiconductors. The optical bandgap was broadened by about 0.35 eV for SrIn0.125Ti0.875O3 and 0.30 eV for SrSc0.125Ti0.875O3. In addition, a noticeable blue-shift of the absorption spectral edge was observed in the two p-type doping systems and a new absorption appeared at around 1.25 to 2.00 eV because of the Drude-type behavior of the free-carrier excitation. The optical transmittance of SrIn0.125Ti0.875O3 and SrSc0.125Ti0.875O3 improved significantly after doping and the transmittances were higher than 85% from 350 to 625 nm. The wide bandgap, small transition probability, and weak absorption because of the low partial density of states of impurities in the Fermi level result in SrIn0.125Ti0.875O3 and SrSc0.125Ti0.875O3 being optically transparent.

Key words: First-principles calculation, SrTiO3, p-type doping, Electronic structure, Optical property


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