Outline
- Abstract
- I. Introduction
- II. Piezoelectric and Spontaneous Polarization
- III. Subband Structure
- IV. Conclusion
رئوس مطالب
- چکیده
- 1. مقدمه
- 2. قطبش پیزوالکتریک و خود به خودی
- 3. ساختار زیر باند
- 4. نتیجه گیری
Abstract
We present a self‐consistent numerical method for calculating the conduction‐band profile and subband structure of AlGaN/GaN single heterojunctions. The subband calculations take into account the piezoelectric and spontaneous polarization effect and the Hartree and exchange‐correlation interaction. We calculate the dependence of electron sheet concentration and subband energies on various structural parameters, such as the width and Al mole fraction of AlGaN, the density of donor impurities in AlGaN, and the density of acceptor impurities in GaN, as well as the electron temperature. The electron sheet concentration was sensitively dependent on the Al mole fraction and width of the AlGaN layer and the doping density of donor impurities in the AlGaN. The calculated results of electron sheet concentration as a function of the Al mole fraction are in excellent agreement with some experimental data available in the literature.
Conclusions
In summary, the conduction-band profile and subband structure of AlGaN/GaN single heterojunctions are calculated by a self-consistent numerical method. Piezoelectric and spontaneous polarization, as well as the many-body interaction, significantly affect the subband structure of AlGaN/GaN single heterojunctions. Electron sheet concentration at the AlGaN/GaN heterojunction is sensitively dependent on the Al mole fraction and the width of AlGaN and the doping density in the AlGaN barrier, while it is rather insensitive to the accepter concentration in the GaN layer and to the electron temperature. However, the acceptor concentration in the GaN and the electron temperature significantly affect the high energy subbands. The theoretical results of electron sheet concentration as a function of the Al mole fraction were in excellent agreement with some available experimental data available in the range of x ≤ 0.27.