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Advances in Condensed Matter Physics
Volume 2017 (2017), Article ID 5652763, 7 pages
https://doi.org/10.1155/2017/5652763
Research Article

External Electric Field Effect on Shallow Donor Impurity States in Zinc-Blende InxGa1−xN/GaN Symmetric Coupled Quantum Dots

1College of Science, North China University of Science and Technology, Tangshan 063000, China
2Publishing Management Center, North China University of Science and Technology, Tangshan 063000, China

Correspondence should be addressed to Guang-Xin Wang

Received 18 July 2017; Accepted 12 September 2017; Published 3 December 2017

Academic Editor: Gongxun Bai

Copyright © 2017 Guang-Xin Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Based on the effective-mass approximation and variational procedure, the ground-state donor binding energy in a cylindrical zinc-blende /GaN symmetric coupled quantum dots (SCQDs) is investigated in the presence of the external electric field. Numerical results show that the donor binding energy increases firstly until a maximum value, and then it begins to drop quickly in all the cases with decreasing the dot radius. As the thickness of left dot and right dot decreases, the donor binding energy increases monotonically at first, reaches a maximum value, and then drops rapidly for an impurity ion located at the right dot center and the middle barrier center. Moreover, the donor binding energy for an impurity ion located at the center of the left dot is insensitive to the variation of dot thickness for large dot thickness due to the Stark effect. Meanwhile, the impurity position plays an important role on the change of the donor binding energy under the external electric field. In particular, the impurity position corresponding to the peak value of the donor binding energy is shifted toward the left QD with increasing the external electric field strength.