中国物理B ›› 2014, Vol. 23 ›› Issue (6): 66801-066801.doi: 10.1088/1674-1056/23/6/066801

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Binding energies of impurity states in strained wurtzite GaN/AlxGa1-xN heterojunctions with finitely thick potential barriers

冯振宇, 班士良, 朱俊   

  1. College of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
  • 收稿日期:2013-08-23 修回日期:2013-12-28 出版日期:2014-06-15 发布日期:2014-06-15
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 60966001) and the Key Project of the Natural Science Foundation of Inner Mongolia Autonomous Region, China (Grant Nos. 20080404Zd02 and 2013ZD02).

Binding energies of impurity states in strained wurtzite GaN/AlxGa1-xN heterojunctions with finitely thick potential barriers

Feng Zhen-Yu (冯振宇), Ban Shi-Liang (班士良), Zhu Jun (朱俊)   

  1. College of Physical Science and Technology, Inner Mongolia University, Hohhot 010021, China
  • Received:2013-08-23 Revised:2013-12-28 Online:2014-06-15 Published:2014-06-15
  • Contact: Feng Zhen-Yu, Ban Shi-Liang E-mail:xiaofzhenyu@163.com;slban@imu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 60966001) and the Key Project of the Natural Science Foundation of Inner Mongolia Autonomous Region, China (Grant Nos. 20080404Zd02 and 2013ZD02).

摘要: Ground state binding energies of donor impurities in a strained wurtzite GaN/AlxGa1-xN heterojunction with a potential barrier of finite thickness are investigated using a variational approach combined with a numerical computation. The built-in electric field due to the spontaneous and piezoelectric polarization, the strain modification due to the lattice mismatch near the interfaces, and the effects of ternary mixed crystals are all taken into account. It is found that the binding energies by using numerical wave functions are obviously greater than those by using variational wave functions when impurities are located in the channel near the interface of a heterojunction. Nevertheless, the binding energies using the former functions are obviously less than using the later functions when impurities are located in the channel far from an interface. The difference between our numerical method and the previous variational method is huge, showing that the former should be adopted in further work for the relevant problems. The binding energies each as a function of hydrostatic pressure are also calculated. But the change is unobvious in comparison with that obtained by the variational method.

关键词: wurtzite, GaN/AlxGa1-xN heterojunction, impurity state, binding energy

Abstract: Ground state binding energies of donor impurities in a strained wurtzite GaN/AlxGa1-xN heterojunction with a potential barrier of finite thickness are investigated using a variational approach combined with a numerical computation. The built-in electric field due to the spontaneous and piezoelectric polarization, the strain modification due to the lattice mismatch near the interfaces, and the effects of ternary mixed crystals are all taken into account. It is found that the binding energies by using numerical wave functions are obviously greater than those by using variational wave functions when impurities are located in the channel near the interface of a heterojunction. Nevertheless, the binding energies using the former functions are obviously less than using the later functions when impurities are located in the channel far from an interface. The difference between our numerical method and the previous variational method is huge, showing that the former should be adopted in further work for the relevant problems. The binding energies each as a function of hydrostatic pressure are also calculated. But the change is unobvious in comparison with that obtained by the variational method.

Key words: wurtzite, GaN/AlxGa1-xN heterojunction, impurity state, binding energy

中图分类号:  (Semiconductors)

  • 68.35.bg
68.47.Fg (Semiconductor surfaces) 74.78.Fk (Multilayers, superlattices, heterostructures)