THE EFFECTS OF QUANTUM CONFINEMENT ON THE BINDING ENERGY OF HYDROGENIC IMPURITIES IN A SPHERICAL QUANTUM DOT

2006 ◽  
Vol 20 (18) ◽  
pp. 1127-1134 ◽  
Author(s):  
A. JOHN PETER
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Shallow Donor ◽  
Donor Impurity ◽  
Hydrogenic Impurity ◽  
Spherical Quantum Dot ◽  
Impurity Position ◽  
Mass Approximation ◽  
Donor Binding Energy ◽  
Parabolic Confinement

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.

EFFECTS OF MAGNETIC AND ELECTRIC FIELDS ON THE HYDROGENIC IMPURITY IN AN ELLIPSOIDAL PARABOLIC QUANTUM DOT

2008 ◽  
Vol 15 (03) ◽  
pp. 201-205 ◽  
Author(s):  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SOKMEN
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Electric Fields ◽  
Magnetic Field Dependence ◽  
Hydrogenic Impurity ◽  
Mass Approximation ◽  
Donor Binding Energy ◽  
Potential Case ◽  
The Magnetic Field ◽  
Parabolic Quantum Dot

The binding energy of a hydrogen-like impurity in an ellipsoidal parabolic quantum dot under the magnetic and electric fields have been discussed by using the effective mass approximation and the variational method. We have calculated the effects of the magnetic and electric fields on the binding energy of donor impurities in the quantum dots with different confinement potentials. We conclude that the structural confinement is very effective, and especially in the weak confinement potential case the magnetic field dependence of the donor binding energy is more pronounced.

scholarly journals Ground-state Shallow-donor Binding Energy in (In,Ga)N/GaN Double QWs Under Temperature, Size, and the Impurity Position Effects

2021 ◽  
Vol 4 (1) ◽  
pp. 1-6
Author(s):  
Redouane En-nadir ◽  
Haddou El Ghazi ◽  
Anouar Jorio ◽  
Izeddine Zorkani
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Ground State ◽  
Shallow Donor ◽  
Effect Of Temperature ◽  
Position Effects ◽  
Coupled Quantum Wells ◽  
Impurity Position ◽  
Mass Approximation ◽  
Donor Binding Energy

In this paper, we study the hydrogen-like donor-impurity binding energy of the ground-state change as a function of the well width under the effect of temperature, size, and impurity position. Within the framework of the effective mass approximation, the Schrodinger-Poisson equation has been solved taken account an on-center hydrogen-like impurity in double QWs with rectangular finite confinement potential profile for 10% of indium concentration in the (well region). The eigenvalues and their correspondent eigenvectors have been obtained by the fined element method (FEM). The obtained results are in good agreement with the literature and show that the temperature, size, and the impurity position have a significant impact on the binding energy of a hydrogen-like impurity in symmetric double coupled quantum wells based on non-polar wurtzite (In,Ga) N/GaN core/Shell.

HYDROGENIC IMPURITY STATES IN WURTZITE ZnO/MgZnO QUANTUM DOT

2010 ◽  
Vol 24 (28) ◽  
pp. 2793-2801
Author(s):  
ZAIPING ZENG ◽  
SHUYI WEI ◽  
JINGBO WEI
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Electric Field ◽  
Ground State ◽  
Asymmetric Distribution ◽  
Electric Field Effect ◽  
Hydrogenic Impurity ◽  
Mass Approximation ◽  
Donor Binding Energy ◽  
The Right

Based on the effective-mass approximation, considering the built-in electric field effect due to the spontaneous and piezoelectric polarizations, the ground-state donor binding energy of a hygrogenic impurity in a cylindrical wurzite (WZ) ZnO / MgZnO strained quantum dot (QD) is investigated variationally. Numerical results show that the ground-state donor binding energy is highly dependent on the Mg composition, the impurity positions and the QD size. The built-in electric field also induces an asymmetric distribution of the ground-state donor binding energy with respect to the center of the QD. In particular, it is found that the ground-state donor binding energy is insensible to the dot height when the impurity is located at the right boundary of the WZ ZnO / MgZnO strained QD if the dot height is large.

Effect of electric field, dielectric screening and conduction band nonparabolicity of donor in a quantum dot

2018 ◽  
Vol 32 (10) ◽  
pp. 1850122 ◽  
Author(s):  
A. Rejo Jeice ◽  
Sr. Gerardin Jayam ◽  
K. S. Joseph Wilson
Keyword(s):  
Binding Energy ◽  
Quantum Dot ◽  
Electric Field ◽  
Conduction Band ◽  
Spherical Quantum Dot ◽  
Donor Binding Energy ◽  
Hydrogenic Donor ◽  
Dielectric Screening ◽  
Parabolic Confinement ◽  
Band Nonparabolicity

The effect of electric field, dielectric screening, conduction band nonparabolicity and effective mass mismatch of a hydrogenic donor in a GaAs/Ga[Formula: see text]Al[Formula: see text]As spherical quantum dot is investigated by assuming parabolic confinement using variational method. In the present work we obtain the increase of binding energy by decreasing the dot size for certain dot radii (50 Å) and the screening function gives uniformly larger values for smaller dot size. The effect of electric field and temperature decrease the donor binding energy whereas the conduction band nonparabolicity leads to increased binding energy.

Influence of Al Composition on Donor Impurity States in Self-Formed GaAs-AlxGa1-xAs Quantum Rings

2013 ◽  
Vol 380-384 ◽  
pp. 4284-4289
Author(s):  
Guang Xin Wang ◽  
Xiu Zhi Duan
Keyword(s):  
Binding Energy ◽  
Electric Field ◽  
Growth Direction ◽  
Uniform Electric Field ◽  
Donor Impurity ◽  
Impurity States ◽  
Quantum Rings ◽  
Mass Approximation ◽  
Donor Binding Energy ◽  
Special Value

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.

THEORETICAL INVESTIGATION ON THE OSCILLATOR STRENGTHS OF ELECTRIC DIPOLE TRANSITIONS IN A SPHERICAL QUANTUM DOT WITH HYDROGENIC DONOR IMPURITY

2012 ◽  
Vol 11 (02) ◽  
pp. 1250020 ◽  
Author(s):  
S. RAJASHABALA ◽  
R. KANNAN
Keyword(s):  
Quantum Dot ◽  
Excited States ◽  
Ionization Energy ◽  
Linear Trend ◽  
Shallow Donor ◽  
Linear Increase ◽  
Oscillator Strengths ◽  
Hydrogenic Impurity ◽  
Spherical Quantum Dot ◽  
Hydrogenic Donor

Dipole transition moment (DTM) of a hydrogenic donor in a spherical quantum dot of GaAs – Ga 1-x Al x As system with finite barrier confinement is obtained. The variational approach within the effective mass approximation is used as the framework for the calculation of donor ionization energy for a few excited states in quantum dot. Calculations of the DTM of an on-center shallow donor hydrogenic impurity in a GaAs quantum dot under hydrostatic pressure are presented. A linear increase in the DTM has been observed, when the dot radius increases from 2 nm to 100 nm. The important conclusions arrived at are (i) ionization energy increases and attains a maximum value occurring for a dot radius of 5 nm, after which the ionization energy decreases gradually as the dot radius increases; (ii) ionization energy for the ground state (1s) is high compared to the excited states (1p and 1d states) and (iii) a linear trend for 1p–1d transition is obtained.

Sign in / Sign up

Export Citation Format

Share Document