中国物理B ›› 2007, Vol. 16 ›› Issue (9): 2791-2797.doi: 10.1088/1009-1963/16/9/049

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Electronic structure and optical properties of In-doped SrTiO3 by density function theory

张志勇1, 贠江妮1, 张富春2   

  1. (1)Information Science and Technology Institution, Northwest University, Xi'an 710069, China; (2)Information Science and Technology Institution, Northwest University, Xi'an 710069, China;College of Physics {\& Electronic Information, Yan'an University, Yan'an 716000, China
  • 收稿日期:2006-12-19 修回日期:2007-02-28 出版日期:2007-09-20 发布日期:2007-09-20
  • 基金资助:
    Project supported by the Natural Science Foundation of Shaanxi Province, China (Grant No 2005F06).

Electronic structure and optical properties of In-doped SrTiO3 by density function theory

Zhang Zhi-Yong(张志勇)a)†, Yun Jiang-Ni(贠江妮)a), and Zhang Fu-Chun(张富春)a)b)   

  1. a Information Science and Technology Institution, Northwest University, Xi'an 710069, China; b College of Physics & Electronic Information, Yan'an University, Yan'an 716000, China
  • Received:2006-12-19 Revised:2007-02-28 Online:2007-09-20 Published:2007-09-20
  • Supported by:
    Project supported by the Natural Science Foundation of Shaanxi Province, China (Grant No 2005F06).

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摘要： The effect of In doping on the electronic structure and optical properties of SrTiO$_{3}$ is investigated by the first-principles calculation of plane wave ultra-soft pseudo-potential based on the density function theory (DFT). The calculated results reveal that due to the hole doping, the Fermi level shifts into valence bands (VBs) for SrTi$_{1-x}$In$_{x}$O$_{3 }$ with $x=0.125$ and the system exhibits p-type degenerate semiconductor features. It is suggested according to the density of states (DOS) of SrTi$_{0.875}$In$_{0.125}$O$_{3}$ that the band structure of p-type SrTiO$_{3}$ can be described by a rigid band model. At the same time, the DOS shifts towards high energies and the optical band gap is broadened. The wide band gap, small transition probability and weak absorption due to the low partial density of states (PDOS) of impurity in the Fermi level result in the optical transparency of the film. The optical transmittance of In doped SrTiO$_{3}$ is higher than 85{\%} in a visible region, and the transmittance improves greatly. And the cut-off wavelength shifts into a blue-light region with the increase of In doping concentration.

关键词: the density function theory, SrTiO_{3}, In-doping, electronic structure, optical transmittance

Abstract: The effect of In doping on the electronic structure and optical properties of SrTiO$_{3}$ is investigated by the first-principles calculation of plane wave ultra-soft pseudo-potential based on the density function theory (DFT). The calculated results reveal that due to the hole doping, the Fermi level shifts into valence bands (VBs) for SrTi$_{1-x}$In$_{x}$O$_{3 }$ with $x=0.125$ and the system exhibits p-type degenerate semiconductor features. It is suggested according to the density of states (DOS) of SrTi$_{0.875}$In$_{0.125}$O$_{3}$ that the band structure of p-type SrTiO$_{3}$ can be described by a rigid band model. At the same time, the DOS shifts towards high energies and the optical band gap is broadened. The wide band gap, small transition probability and weak absorption due to the low partial density of states (PDOS) of impurity in the Fermi level result in the optical transparency of the film. The optical transmittance of In doped SrTiO$_{3}$ is higher than 85% in a visible region, and the transmittance improves greatly. And the cut-off wavelength shifts into a blue-light region with the increase of In doping concentration.

Key words: the density function theory, SrTiO$_{3}$, In-doping, electronic structure, optical transmittance

中图分类号:  (Semiconductor compounds)

  • 71.20.Nr
61.72.up (Other materials) 71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))