中国物理B ›› 2006, Vol. 15 ›› Issue (7): 1585-1590.doi: 10.1088/1009-1963/15/7/035

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First principles study on the structural,electronic and optical properties of diluted magnetic semiconductors Zn1-xCoxX (X=S, Se, Te)

欧阳企振1, 叶志清1, 雷敏生1, 欧阳楚英2, 熊志华2, 刘国栋3   

  1. (1)Department of Physics, Jiangxi Normal University, Nanchang 330027, China; (2)Department of Physics, Jiangxi Normal University, Nanchang 330027, China;Key Laboratory for Opto-electronics of Jiangxi Province,Jiangxi Science & Technology Normal University,Nanchang 330013, China; (3)Key Laboratory for Opto-electronics of Jiangxi Province,Jiangxi Science & Technology Normal University,Nanchang 330013, China
  • 收稿日期:2005-12-22 修回日期:2006-04-03 出版日期:2006-07-20 发布日期:2006-07-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10564002) and the Open Foundations of Key Laboratory for Opto--electronics of Jiangxi Province, China (Grant Nos 2004003 and 2004008), the Natural Science Foundation of Jiangx

First principles study on the structural,electronic and optical properties of diluted magnetic semiconductors Zn1-xCoxX (X=S, Se, Te)

Ouyang Chu-Ying (欧阳楚英)ab, Xiong Zhi-Hua (熊志华)ab, Ouyang Qi-Zhen (欧阳企振)a, Liu Guo-Dong (刘国栋)b, Ye Zhi-Qing (叶志清)a, Lei Min-Sheng (雷敏生)a   

  1. a Department of Physics, Jiangxi Normal University, Nanchang 330027, China; b Key Laboratory for Opto-electronics of Jiangxi Province,Jiangxi Science & Technology Normal University, Nanchang 330013, China
  • Received:2005-12-22 Revised:2006-04-03 Online:2006-07-20 Published:2006-07-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10564002) and the Open Foundations of Key Laboratory for Opto--electronics of Jiangxi Province, China (Grant Nos 2004003 and 2004008), the Natural Science Foundation of Jiangx

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摘要： The electronic and optical properties of zincblende ZnX(X=S, Se, Te) and ZnX:Co are studied from density functional theory (DFT) based first principles calculations. The local crystal structure changes around the Co atoms in the lattice are studied after Co atoms are doped. It is shown that the Co-doped materials have smaller lattice constant (about 0.6%--0.9%). This is mainly due to the shortened Co--X bond length. The (partial) density of states (DOS) is calculated and differences between the pure and doped materials are studied. Results show that for the Co-doped materials, the valence bands are moving upward due to the existence of Co 3d electron states while the conductance bands are moving downward due to the reduced lattice constants. This results in the narrowed band gap of the doped materials. The complex dielectric indices and the absorption coefficients are calculated to examine the influences of the Co atoms on the optical properties. Results show that for the Co-doped materials, the absorption peaks in the high wavelength region are not as sharp and distinct as the undoped materials, and the absorption ranges are extended to even higher wavelength region.

关键词: first principles, diluted magnetic semiconductors, optical properties, electronic properties

Abstract: The electronic and optical properties of zincblende ZnX(X=S, Se, Te) and ZnX:Co are studied from density functional theory (DFT) based first principles calculations. The local crystal structure changes around the Co atoms in the lattice are studied after Co atoms are doped. It is shown that the Co-doped materials have smaller lattice constant (about 0.6%--0.9%). This is mainly due to the shortened Co--X bond length. The (partial) density of states (DOS) is calculated and differences between the pure and doped materials are studied. Results show that for the Co-doped materials, the valence bands are moving upward due to the existence of Co 3d electron states while the conductance bands are moving downward due to the reduced lattice constants. This results in the narrowed band gap of the doped materials. The complex dielectric indices and the absorption coefficients are calculated to examine the influences of the Co atoms on the optical properties. Results show that for the Co-doped materials, the absorption peaks in the high wavelength region are not as sharp and distinct as the undoped materials, and the absorption ranges are extended to even higher wavelength region.

Key words: first principles, diluted magnetic semiconductors, optical properties, electronic properties

中图分类号:  (Magnetic semiconductors)

  • 75.50.Pp
61.66.Fn (Inorganic compounds) 71.20.Ps (Other inorganic compounds) 78.20.Ci (Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity))