Behavior of Donor Impurity Binding Energy Confined In a GaAs Constant Total Effective Radius Multi-Shell Quantum Dots: Dielectric Mismatch Effects

2017 ◽  
Vol 41 (4) ◽  
pp. 1075-1081
Author(s):  
M. Solaimani ◽  
B. Babayar Razlighi
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Effective Radius ◽  
Donor Impurity ◽  
Dielectric Mismatch

Osscillating Binding Energy of a Donor Impurity Confined Within CdS-SiO2 Constant Total Effective Radius Multi-Shells Quantum Dots

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650003
Author(s):  
M. Solaimani
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Quantum Dot ◽  
Outer Radius ◽  
Effective Radius ◽  
Wave Functions ◽  
Donor Impurity ◽  
Single Donor ◽  
Number Variation

In this paper, we have studied the effect of a number of wells and quantum dot thickness on binding energy of a single donor impurity confined within a CdS-SiO2 constant total effective radius multi-shells quantum dot (CTER-MSQD) system. We have shown that impurity binding energy versus number of wells in a quantum dot with fixed outer radius oscillates when amplitude increases. By using well number variation, adding impurity and changing quantum dot radius as three tuning tools, localization of wave-functions in each part of the quantum dot along the radius has been now made possible. Finally, adding the impurity leads to more probability of finding the electrons in the wells near the center of the quantum dot.

BINDING ENERGIES OF HYDROGENIC IMPURITIES ON-CENTER AND OFF-CENTER IN CYLINDRICAL QUANTUM DOTS UNDER ELECTRIC AND MAGNETIC FIELDS

2010 ◽  
Vol 24 (22) ◽  
pp. 4293-4304 ◽  
Author(s):  
SHENG WANG ◽  
GUOZHU WEI ◽  
GUANGYU YI
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Effective Radius ◽  
Binding Energies ◽  
Hydrogenic Impurity ◽  
Lateral Confinement ◽  
Electric And Magnetic Fields

The ground-state binding energies of a hydrogenic impurity in cylindrical quantum dots (QDs) subjected to external electric and magnetic fields are investigated using the finite-difference method within the quasi-one-dimensional effective potential model. The QD is modeled by superposing a square-well potential and a strong lateral confinement potential by the combination of a parabolic potential and a changeable magnetic field. We define an effective radius of a cylindrical QD which can describe the strength of the lateral confinement. The effects of the electric fields are less important when the effective radius is very tiny, and the effects are manifested as the effective radius increases. Meanwhile, one finds that the binding energies highly depend on the impurity positions under the applied transverse fields. When the impurity is located at the right half of the cylinder, the electric field pushes the electron to the left side, then the binding energy decreases; when the impurity is located at the left, the binding energy first increases and reaches a peak value, then deceases with the electric field.

Binding Energy And Absorption of Donor Impurity In Spherical GaAs/AlxGa1-x As Quantum Dots With Konwent Potential

2021 ◽  
Author(s):  
E. B. Al ◽  
E. Kasapoglu ◽  
H. Sari ◽  
I. Sökmen ◽  
C. A. Duque
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Electromagnetically Induced Transparency ◽  
Shallow Donor ◽  
Donor Impurity ◽  
Eigenvalues And Eigenfunctions ◽  
Different Types ◽  
Matrix Expansion ◽  
Diagonalization Method ◽  
Induced Transparency

Abstract In this study, the electronic and optical properties of single or core/shell quantum dots, which are formed depending on the parameters in the selected Konwent potential, are investigated. Namely, the effects of the size and geometric shapes of quantum dots on the binding energy of the on-center donor impurity, the total absorption coefficient and refractive index which are including transitions between the some confined states, and the electromagnetically induced transparency between the lowest six confined states related to the donor impurity are investigated. We have used the diagonalization method by choosing a wave function based on the Bessel and Spherical Harmonics orthonormal function to find the eigenvalues and eigenfunctions of the electron confined within the quantum dots which have different types mentioned above. To calculate the optical absorption coefficients and electromagnetically induced transparency related to shallow-donor impurity, a two- and three-level approach in the density matrix expansion is used, respectively.

Excitonic quasimolecules containing of two quantum dots

2016 ◽  
pp. 4024-4028 ◽  
Author(s):  
Sergey I. Pokutnyi ◽  
Wlodzimierz Salejda
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Exchange Interaction ◽  
Coulomb Interaction ◽  
Silicate Glass ◽  
Glass Matrix ◽  
Silicate Glass Matrix

The possibility of occurrence of the excitonic  quasimolecule formed of spatially separated electrons and holes in a nanosystem that consists  of  CuO quantum dots synthesized in a silicate glass matrix. It is shown that the major contribution to the excitonic quasimolecule binding energy is made by the energy of the exchange interaction of electrons with holes and this contribution is much more substantial than the contribution of the energy of Coulomb interaction between the electrons and holes.

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