中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3803-3908.doi: 10.1088/1009-1963/16/12/041

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First principle study of nitrogen vacancy in aluminium nitride

耶红刚, 陈光德, 竹有章, 吕惠民   

  1. Department of Applied Physics, Xi'an Jiaotong University, Xi'an 710049, China
  • 出版日期:2007-12-20 发布日期:2007-12-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No~10474078).

First principle study of nitrogen vacancy in aluminium nitride

Ye Hong-Gang(耶红刚)†, Chen Guang-De(陈光德), Zhu You-Zhang(竹有章), and Lü Hui-Min(吕惠民)   

  1. Department of Applied Physics, Xi'an Jiaotong University, Xi'an 710049, China
  • Online:2007-12-20 Published:2007-12-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No~10474078).

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摘要： In the framework of density functional theory, using the plane-wave pseudopotential method, the nitrogen vacancy ($V_{\rm N})$ in both wurtzite and zinc-blende AlN is studied by the supercell approach. The atom configuration, density of states, and formation energies of various charge states are calculated. Two defect states are introduced by the defect, which are a doubly occupied single state above the valance band maximum (VBM) and a singly occupied triple state below the conduction band minimum (CBM) for wurtzite AlN and above the CBM for zinc-blende AlN. So $V_{\rm N}$ acts as a deep donor in wurtzite AlN and a shallow donor in zinc-blende AlN. A thermodynamic transition level $E({3 + } \mathord{\left/ {\vphantom {{3 + } + }} \right. \kern-\nulldelimiterspace} + )$ with very low formation energy appears at 0.7 and 0.6eV above the VBM in wurtzite and zinc-blende structure respectively, which may have a wide shift to the low energy side if atoms surrounding the defect are not fully relaxed. Several other transition levels appear in the upper part of the bandgap. The number of these levels decreases with the structure relaxation. However, these levels are unimportant to AlN properties because of their high formation energy.

关键词: aluminium nitride, density of states, defect state, formation energy

Abstract: In the framework of density functional theory, using the plane-wave pseudopotential method, the nitrogen vacancy ($V_{\rm N})$ in both wurtzite and zinc-blende AlN is studied by the supercell approach. The atom configuration, density of states, and formation energies of various charge states are calculated. Two defect states are introduced by the defect, which are a doubly occupied single state above the valance band maximum (VBM) and a singly occupied triple state below the conduction band minimum (CBM) for wurtzite AlN and above the CBM for zinc-blende AlN. So $V_{\rm N}$ acts as a deep donor in wurtzite AlN and a shallow donor in zinc-blende AlN. A thermodynamic transition level $E(3+/+)$ with very low formation energy appears at 0.7 and 0.6eV above the VBM in wurtzite and zinc-blende structure respectively, which may have a wide shift to the low energy side if atoms surrounding the defect are not fully relaxed. Several other transition levels appear in the upper part of the bandgap. The number of these levels decreases with the structure relaxation. However, these levels are unimportant to AlN properties because of their high formation energy.

Key words: aluminium nitride, density of states, defect state, formation energy

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

  • 71.15.Mb
61.72.J- (Point defects and defect clusters) 71.15.Dx (Computational methodology (Brillouin zone sampling, iterative diagonalization, pseudopotential construction)) 71.20.Nr (Semiconductor compounds) 71.55.Eq (III-V semiconductors)