Binding Energy of Donor Impurity in a Rectangular Semiconductor GaAs Quantum Dot with Electric Field

2014 ◽  
Vol 687-691 ◽  
pp. 3407-3410
Author(s):  
Kang Yun ◽  
Sheng Wang ◽  
Xian Li Li

Within the quasi-one-dimensional effective potential model and effective mass approximation, we calculate the ground and the first few excited state binding energies of a donor impurity in a rectangular quantum dot (RQD) in the presence of electric field. We discuss detailedly dependence of the binding energies on the impurity positions. The results show that the binding energy is the largest when the impurity is located at the center of RQD with zero field and is lowest when the impurity is located at the corner of the RQD. The peak strengths and positions of the probability density in RQD appear to be the critical control on such impurity-induced dependence. We believe our results can provide an indication for design of some photoelectric devices constructed based on GaAs RQD structures.

2019 ◽  
Vol 33 (32) ◽  
pp. 1950386
Author(s):  
Shi-Hua Chen

The first-excited-state (ES) binding energy of hydrogenic impurity bound polaron in an anisotropic quantum dot (QD) is obtained by constructing a variational wavefunction under the action of a uniform external electric field. As for a comparison, the ground-state (GS) binding energy of the system is also included. We apply numerical calculations to KBr QD with stronger electron–phonon (E–P) interaction in which the new variational wavefunction is adopted. We analyzed specifically the effects of electric field and the effects of both the position of the impurity and confinement lengths in the xy-plane and the [Formula: see text] direction on the ground and the first-ES binding energies (BEs). The results show that the selected trial wavefunction in the ES is appropriate and effective for the current research system.


2012 ◽  
Vol 26 (06) ◽  
pp. 1250013 ◽  
Author(s):  
F. UNGAN ◽  
U. YESILGUL ◽  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SOKMEN

The effects of nitrogen and indium mole concentration on the intersubband optical absorption for (1–2) transition and the binding energy of the shallow-donor impurities in a Ga 1-x In x N y As 1-y/ GaAs / Al 0.3 Ga 0.7 As quantum well under the electric field is theoretically calculated within the framework of the effective-mass approximation. Results are obtained for several concentrations of nitrogen and indium, and the applied electric field. The numerical results show that the intersubband transitions and the impurity binding energy strongly depend on the nitrogen and indium concentrations.


2013 ◽  
Vol 380-384 ◽  
pp. 4284-4289
Author(s):  
Guang Xin Wang ◽  
Xiu Zhi Duan

Based on the the effective mass approximation and variational approach, the donor impurity states confined in self-formed GaAs/AlxGa1-xAs quantum rings (QRs) are investigated theoretically. A uniform electric field is applied along the growth direction of the QR. The different effective masses in the different regions of the GaAs/AlxGa1-xAs QR are taken into consideration. Numerical results show that the binding energy of a donor impurity increases gradually, reaches a maximum value, and then decreases quickly to the special value as the QR height decreases. Given a fixed QR size, the binding energy increases for the impurity located at the center of the QR when the Al composition increases. In addition, it can also be found that when the applied electric field strength increases, the donor binding energy increases for impurities localized at the negative z axis of the QR; however, the donor binding energy decreases slightly for impurities located at the center and positive z axis of the QR.


2012 ◽  
Vol 376 (42-43) ◽  
pp. 2712-2716 ◽  
Author(s):  
Zaiping Zeng ◽  
Christos S. Garoufalis ◽  
Sotirios Baskoutas ◽  
Andreas F. Terzis

2006 ◽  
Vol 20 (18) ◽  
pp. 1127-1134 ◽  
Author(s):  
A. JOHN PETER

The binding energy of a shallow hydrogenic impurity of a spherical quantum dot confined by harmonic oscillator-like and by rectangular well-like potentials, using a variational procedure within the effective mass approximation, has been determined. The calculations of the binding energy of the donor impurity as a function of the system geometry, and the donor impurity position have been investigated. The binding energy of shallow donor impurity depends not only on the quantum confinements but also on the impurity position. Our results reveal that (i) the donor binding energy decreases as the dot size increases irrespective of the impurity position, and (ii) the binding energy values of rectangular confinement are larger than the values of parabolic confinement and (iii) the rectangular confinement is better than the parabolic confinement in a spherical quantum dot.


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