Stark shift and photoionization cross section of on-center and off-center donor impurity in a core/shell ellipsoidal quantum dot

2018 ◽  
Vol 98 ◽  
pp. 111-117 ◽  
Author(s):  
L. Shi ◽  
Z.W. Yan
Keyword(s):  
Quantum Dot ◽  
Cross Section ◽  
Photoionization Cross Section ◽  
Stark Shift ◽  
Core Shell ◽  
Donor Impurity ◽  
Ellipsoidal Quantum Dot

Photoionization cross section and binding energy of single dopant in hollow cylindrical core/shell quantum dot

2017 ◽  
Vol 121 (6) ◽  
pp. 064303 ◽  
Author(s):  
E. Feddi ◽  
M. El-Yadri ◽  
F. Dujardin ◽  
R. L. Restrepo ◽  
C. A. Duque
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Cross Section ◽  
Photoionization Cross Section ◽  
Core Shell

Binding energies and photoionization cross-sections of donor and acceptor impurities in inverted core/shell ellipsoidal quantum dots: Effects of magnetic field, ellipsoid anisotropy and impurity position

2019 ◽  
Vol 33 (13) ◽  
pp. 1950131 ◽  
Author(s):  
Lei Shi ◽  
Zu-Wei Yan
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Cross Section ◽  
Cross Sections ◽  
Applied Magnetic Field ◽  
Photoionization Cross Section ◽  
Binding Energies ◽  
Core Shell ◽  
Perturbation Approach ◽  
Donor And Acceptor

Within the framework of the effective-mass approximation and by using a variational and perturbation approach, the binding energies and photoionization cross-sections of donor and acceptor impurities in an inverted core/shell ellipsoidal spherical quantum dot under an applied magnetic field have been studied. We have calculated the binding energies of both donor and acceptor impurities as a function of the core and shell sizes and shapes with different impurity positions under the applied magnetic field. In addition, the corresponding photoionization cross-section is calculated. Our results show that the binding energy of the acceptor impurity is larger than that of the donor impurity, and both of them with different impurity positions and quantum ellipsoid anisotropies will exhibit a nonmonotonic change. The peak value of the photoionization cross-section will reach a maximum with the increasing ratio R1/R2. It is found that the applied magnetic field can be an effective means of enhancing the photoionization cross-section of an impurity state in such core/shell quantum dot system.

Binding energies and photoionization cross-sections of donor impurities in GaN/AlxGa1−xN spherical quantum dot under hydrostatic pressure

2020 ◽  
Vol 34 (14) ◽  
pp. 2050153
Author(s):  
Shuo Li ◽  
Lei Shi ◽  
Zu-Wei Yan
Keyword(s):  
Hydrostatic Pressure ◽  
Binding Energy ◽  
Quantum Dot ◽  
Cross Section ◽  
Cross Sections ◽  
Photoionization Cross Section ◽  
Binding Energies ◽  
Core Shell ◽  
Core Size ◽  
Shell Size

In this paper, the binding energy and photoionization cross-section of donor impurity state in [Formula: see text] quantum dot structure are studied theoretically by using variational method. The variation of binding energy and photoionization cross-section with core and shell sizes at different impurity locations under hydrostatic pressure is calculated numerically. The results show that the binding energy decreases monotonously with the core size at different impurity locations for [Formula: see text] core/shell quantum dot. In contrast, for the inverted core/shell quantum dot, the binding energy exhibits different trends with the increase of core size at different impurity locations. But the binding energy decreases monotonically with the shell size for both of them. Moreover, when the photon energy is approximately equal to the donor binding energy, the peak of the photoionization cross-section appears. There will be different peak shifts under different conditions, and its peak intensity increases with the increase of core and shell sizes. When the hydrostatic pressure is applied, the binding energy and the peak strength of the photoionization cross-section increase with the increase of the pressure.

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