中国物理B ›› 2009, Vol. 18 ›› Issue (10): 4449-4455.doi: 10.1088/1674-1056/18/10/057

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Pressure influence on the Stark effect of impurity states in a strained wurtzite GaN/AlxGa1-xN heterojunction

班士良1, 张敏2   

  1. (1)School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China; (2)School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China;College of Physics and Electron Information, Inner Mongolia Normal University, Hohhot 010022, China
  • 收稿日期:2007-11-20 修回日期:2009-05-30 出版日期:2009-10-20 发布日期:2009-10-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 60566002).

Pressure influence on the Stark effect of impurity states in a strained wurtzite GaN/AlxGa1-xN heterojunction

Zhang Min(张敏)a)b) and Ban Shi-Liang(班士良)a)†   

  1. a School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China; b College of Physics and Electron Information, Inner Mongolia Normal University, Hohhot 010022, China
  • Received:2007-11-20 Revised:2009-05-30 Online:2009-10-20 Published:2009-10-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 60566002).

摘要: A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric field by using a simplified coherent potential approximation. Considering the biaxial strain due to lattice mismatch or epitaxial growth and the uniaxial strains effects, we investigated the Stark energy shift led by an external electric field for impurity states as functions of pressure as well as the impurity position, Al component and areal electron density. The numerical result shows that the binding energy near linearly increases with pressure from 0 to 10~GPa. It is also found that the binding energy as a function of the electric field perpendicular to the interface shows an un-linear red shift or a blue shift for different impurity positions. The effect of increasing x on blue shift is more significant than that on the red shift for the impurity in the channel near the interface. The pressure influence on the Stark shift is more obvious with increase of electric field and the distance between an impurity and the interface. The increase of pressure decreases the blue shift but increases the red shift.

Abstract: A variational method is adopted to investigate the properties of shallow impurity states near the interface in a free strained wurtzite GaN/AlxGa1-xN heterojunction under hydrostatic pressure and external electric field by using a simplified coherent potential approximation. Considering the biaxial strain due to lattice mismatch or epitaxial growth and the uniaxial strains effects, we investigated the Stark energy shift led by an external electric field for impurity states as functions of pressure as well as the impurity position, Al component and areal electron density. The numerical result shows that the binding energy near linearly increases with pressure from 0 to 10 GPa. It is also found that the binding energy as a function of the electric field perpendicular to the interface shows an un-linear red shift or a blue shift for different impurity positions. The effect of increasing x on blue shift is more significant than that on the red shift for the impurity in the channel near the interface. The pressure influence on the Stark shift is more obvious with increase of electric field and the distance between an impurity and the interface. The increase of pressure decreases the blue shift but increases the red shift.

Key words: GaN/AlxGa1-xN, strain, pressure, Stark effect, binding energy of impurity state

中图分类号:  (III-V semiconductors)

  • 71.55.Eq
71.70.Ej (Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect) 73.40.Kp (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)