中国物理B ›› 2018, Vol. 27 ›› Issue (1): 17101-017101.doi: 10.1088/1674-1056/27/1/017101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Density functional theory analysis of electronic structure and optical properties of La-doped Cd2SnO4 transparent conducting oxide

Mei Tang(汤梅), Jia-Xiang Shang(尚家香), Yue Zhang(张跃)   

  1. 1 School of Materials Science & Engineering, Beihang University, Beijing 100191, China;
    2 Journal Publishing Center of Tsinghua University Press, Beijing 100084, China
  • 收稿日期:2017-08-23 修回日期:2017-10-18 出版日期:2018-01-05 发布日期:2018-01-05
  • 通讯作者: Yue Zhang E-mail:zhangy@buaa.edu.cn

Density functional theory analysis of electronic structure and optical properties of La-doped Cd2SnO4 transparent conducting oxide

Mei Tang(汤梅)1,2, Jia-Xiang Shang(尚家香)1, Yue Zhang(张跃)1   

  1. 1 School of Materials Science & Engineering, Beihang University, Beijing 100191, China;
    2 Journal Publishing Center of Tsinghua University Press, Beijing 100084, China
  • Received:2017-08-23 Revised:2017-10-18 Online:2018-01-05 Published:2018-01-05
  • Contact: Yue Zhang E-mail:zhangy@buaa.edu.cn

摘要: The electronic structural, effective masses of carriers, and optical properties of pure and La-doped Cd2SnO4 are calculated by using the first-principles method based on the density functional theory. Using the GGA+U method, we show that Cd2SnO4 is a direct band-gap semiconductor with a band gap of 2.216 eV, the band gap decreases to 2.02 eV and the Fermi energy level moves to the conduction band after La doping. The density of states of Cd2SnO4 shows that the bottom of the conduction band is composed of Cd 5s, Sn 5s, and Sn 5p orbits, the top of the valence band is composed of Cd 4d and O 2p, and the La 5d orbital is hybridized with the O 2p orbital, which plays a key role at the conduction band bottom after La doping. The effective masses at the conduction band bottom of pure and La-doped Cd2SnO4 are 0.18m0 and 0.092m0, respectively, which indicates that the electrical conductivity of Cd2SnO4 after La doping is improved. The calculated optical properties show that the optical transmittance of La-doped Cd2SnO4 is 92%, the optical absorption edge is slightly blue shifted, and the optical band gap is increased to 3.263 eV. All the results indicate that the conductivity and optical transmittance of Cd2SnO4 can be improved by doping La.

关键词: transparent conducting oxides, electronic band structure, first-principle calculations, optical properties

Abstract: The electronic structural, effective masses of carriers, and optical properties of pure and La-doped Cd2SnO4 are calculated by using the first-principles method based on the density functional theory. Using the GGA+U method, we show that Cd2SnO4 is a direct band-gap semiconductor with a band gap of 2.216 eV, the band gap decreases to 2.02 eV and the Fermi energy level moves to the conduction band after La doping. The density of states of Cd2SnO4 shows that the bottom of the conduction band is composed of Cd 5s, Sn 5s, and Sn 5p orbits, the top of the valence band is composed of Cd 4d and O 2p, and the La 5d orbital is hybridized with the O 2p orbital, which plays a key role at the conduction band bottom after La doping. The effective masses at the conduction band bottom of pure and La-doped Cd2SnO4 are 0.18m0 and 0.092m0, respectively, which indicates that the electrical conductivity of Cd2SnO4 after La doping is improved. The calculated optical properties show that the optical transmittance of La-doped Cd2SnO4 is 92%, the optical absorption edge is slightly blue shifted, and the optical band gap is increased to 3.263 eV. All the results indicate that the conductivity and optical transmittance of Cd2SnO4 can be improved by doping La.

Key words: transparent conducting oxides, electronic band structure, first-principle calculations, optical properties

中图分类号:  (Density functional theory, local density approximation, gradient and other corrections)

  • 71.15.Mb
71.20.-b (Electron density of states and band structure of crystalline solids) 78.20.-e (Optical properties of bulk materials and thin films) 42.50.Gy (Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)