Binding Energy Of Donor Impurity Research Articles

Optical absorption in core–shell quantum antidot with donor impurity under applied co-directed electric and magnetic fields

In this article, we have investigated an electron energy spectrum, optical absorption coefficients (OACs) and polarizability under the effect of the co-directed electric and magnetic fields in the multilayer spherical quantum antidot (MSQAD) Al0.3 Ga0.7 As/GaAs/Al0.3Ga0.7 As with off-center impurity. The calculations were done for different dot sizes within the effective mass approximation using the matrix method. The dependence of the total, linear, and nonlinear OACs on the incident photon energy is calculated considering the intraband electron quantum transitions. The donor polarizability and impurity binding energy as function of electric field intensity are obtained at different values of the magnetic field induction.

Modeling of the Stark shift and binding energy of shallow donor-impurity in $$\mathrm{GaAs}/{\mathrm{Al}}_{0.3}{\mathrm{Ga}}_{0.7}\mathrm{As}$$ core/shell quantum disk: effects of lateral directed applied electric field including the core/shell sizes

Modeling of the Stark shift and binding energy of shallow donor-impurity in $$\mathrm{GaAs}/{\mathrm{Al}}_{0.3}{\mathrm{Ga}}_{0.7}\mathrm{As}$$ core/shell quantum disk: effects of lateral directed applied electric field including the core/shell sizes

Analyzing the combined influences of external electric field, impurity-location, in-content, and QW’s number on donor-impurity binding energy in multiple quantum wells with finite squared potential

Analyzing the combined influences of external electric field, impurity-location, in-content, and QW’s number on donor-impurity binding energy in multiple quantum wells with finite squared potential

The effects of lateral electric field, effective-mass position-dependent, and dimension on the donor-impurity binding energy and electron-impurity distance in GaAs-based quantum disk

The effects of lateral electric field, effective-mass position-dependent, and dimension on the donor-impurity binding energy and electron-impurity distance in GaAs-based quantum disk

The impact of the electric field on the photoionization cross section, polarizability, and donor impurity binding energy in multilayered spherical quantum dot

The impact of the electric field on the photoionization cross section, polarizability, and donor impurity binding energy in multilayered spherical quantum dot

Effects of applied magnetic field and pressure on the diamagnetic susceptibility and binding energy of donor impurity in GaAs quantum dot considering the non-parabolicity model’s influence

ABSTRACT In this article, we investigate the influence of the hydrostatic pressure, magnetic field, and conduction band non-parabolicity on both the diamagnetic susceptibility and the binding energy of shallow donor impurity in a quantum disk made out of GaAs. The Hamiltonian of the investigated problem has been solved within the framework of the effective-mass approximation. The energy minimisation has been performed using a variational approach. Our results reveal that both the diamagnetic susceptibility and binding energy have been reduced with increasing the disk size. Moreover, the diamagnetic susceptibility increases as the impurity moves from the extremity to the centre of the disk. However, both the diamagnetic susceptibility and binding energy have been improved under applied magnetic field, hydrostatic pressure, and by considering the conduction band non-parabolicity model as well. We hope that the reported results will be a modest contribution to further theoretical research in the field of nanostructures.

Intense terahertz laser field induced electro-magneto-donor impurity associated photoionization cross-section in Gaussian quantum wires

Using expressions derived within the compact density matrix approach, the peaks of optical absorption and the changes of refractive index of a hydrogenic impurity in a GaAs/GaAlAs Gaussian quantum well wire are calculated taking into account the influence of static electric, magnetic and intense laser fields. The photoionization cross section, with normalized photon energy, is computed for different values of static electric field, magnetic field, and laser dressing parameter. The dipole moment matrix elements and the transition energy between ground and first excited state energy levels are computed as functions of quantum wire width and confinement potential depth, with and without external perturbations. Donor impurity binding energy is investigated in presence of the aforementioned electromagnetic probes, using parabolic band and effective mass approximations. The results show that the absorption coefficients depend on the transition energy difference between initial and final states involved as well as on the corresponding polarization response via dipole matrix elements. Discussed optical properties are field-sensitive and they can be tuned within the desired energy ranges using these external perturbations. • Peaks of optical absorption and changes of refractive index of a hydrogenic impurity in a GaAs/GaAlAs Gaussian quantum well wire are calculated. • They have been computed taking into account the influence of static electric, magnetic and intense laser fields. • Photoionization cross section, with normalized photon energy, is computed. • Donor impurity binding energy is investigated in the presence of aforementioned electromagnetic-probes, using parabolic band and effective mass approximations. • Discussed optical properties are field-sensitive and they can be tuned within the desired energy ranges using these external perturbations.

Study of photoionization cross section and binding energy of shallow donor impurity in multilayered spherical quantum dot

In the framework of the effective mass approximation and by using the finite element method , we have studied the simultaneous effects of position dependent effective mass (PDEM) and dielectric function on the shallow donor impurity binding energy and photoionization cross section in a multilayered spherical quantum dot . We have also investigated the influence of conduction band nonparabolicity and polaronic mass on the both binding energy and photoionization cross section (PCS). The obtained results have shown that the nonparabolicity and polaronic mass effects enhance the binding energy and photoionization cross section. Furthermore, it can be concluded from this research that the binding energy and the PCS are strongly dependent on the geometrical parameters, and PDEM. Changes in binding energy and photoionization cross section have physical reasons, which are discussed in details. • The photoionization cross section (PCS) and the binding energy are strongly dependent on the width of the structure layers. • The conduction band nonparabolicity and the polaronic mass effects enhance the binding energy and reduce the PCS peak magnitude. • The dependence of the dielectric function ε ( r ) on the electron coordinates makes the amplitude peak of the PCS take high values.

Effect of electric field on the binding energy and polarisation of shallow donor in a GaAs/Ga1-xAlxAs pillbox surrounded by Ga1-yAlyAs

ABSTRACT Using a variational method in the effective mass approximation, we calculated the binding energy and polarisation of a shallow donor in a GaAs-Ga1-xAlxAs pillbox surrounded by Ga1-yAlyAs. We present our results as a function of the impurity positions and the strength of the electric field for different shapes of the pillbox with constant volume. It is found that the binding energy and polarisation of donor impurity depend strongly on the shape of the pillbox, the position of the impurity, the intensity of the electric field and the thickness of the potential barrier.

Binding energy, polarizability, and diamagnetic response of shallow donor impurity in zinc blende GaN quantum dots

In this theoretical investigation, the binding energy, the binding energy Stark-shift, the dipole moment, the polarizability, and the diamagnetic susceptibility related with a confined shallow donor impurity in zinc blende GaN conical-shaped quantum dots are calculated under the effect of an electric field applied along the z-direction. Calculations have been made by using a variational approach within the infinite confining potential model and considering the parabolic conduction band and the effective mass approximations. The results suggest important dependencies of the calculated physical properties on the variation of the dot dimensions, axial impurity position, and the intensity of the applied electric field. It is observed that: i) the binding energy Stark shift increases up to a maximum value and then decreases with increasing the strength of the electric field, and it is strongly influenced by the impurity position and geometrical parameters, ii) for a fixed electric field value, the binding energy Stark shift is always an increasing function of the dot height, and iii) for fixed electric field values, the binding energy Stark shift shows a mixed behavior concerning the dot radius, i.e., for low field strength, the binding energy is always a growing function of the radius, and for large field strengths, such physical quantity grows with the radius up to a maximum and then decreases. Furthermore, the electric field (the strong quantum confinement) enhances slightly (diminishes) the diamagnetic susceptibility of impurity.

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

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.

Study of hydrostatic pressure, electric and magnetic fields effects on the donor binding energy in multilayer cylindrical quantum dots

The current paper provides a theoretical study of the binding energy of an off-center donor impurity in wurtzite InGaN/GaN multilayer cylindrical quantum dots (MCQDs). The Schrödinger equation related to the shallow donor impurity has been solved by the finite element method (FEM) using a parabolic confinement potential in the radial direction and a square one in the z direction within the effective-mass and a parabolic conduction band approximation. Furthermore, we have studied the external perturbations on the donor binding energy such as: hydrostatic pressure, magnetic and electric fields as well as the effect of strain induced by the lattice mismatch. Moreover, the binding energy has been calculated as a function of the geometric parameters of the structure, indium concentration x in the InxGa1−xN alloy and impurity position z0. Our main findings show that the binding energy is more influenced by the electric field for large sizes, by the hydrostatic pressure and the magnetic field for all sizes, especially for wide radius R, barrier Lb and thin Ld. Additionally, the results show that the lattice mismatch has an impact on the binding energy, mostly at low pressure.

Binding energy and diamagnetic susceptibility of donor impurities in quantum dots with different geometries and potentials

We study the binding energy and diamagnetic susceptibility of a donor impurity in multi-well cylindrical and spherical quantum dot systems with triangular, rectangular, saw-tooth and sinusoidal-shaped confining potentials. To tune the binding energy and diamagnetic susceptibility of a donor impurity, we used different parameters such as number of wells, composition parameter x, shape on the potential profile, shape of the quantum dot, etc. We discuss the effect of the symmetry on the step-like structure of the energy level versus the number of wells. We describe the wave function engineering (localization or delocalization) in proposed systems. We determined the situations that lead to the maximum (minimum) binding energy and diamagnetic susceptibility in the cylindrical (spherical) quantum dots. By using the number of wells, we change the monotonic increasing behavior of binding energy to a monotonic decreasing behavior. We illustrate that spherical quantum dot systems are more tunable than the cylindrical ones.

Stark shift of binding energy for on and off-center donor impurities in quantum rings under the influence of charged rods electric fields

In the present work, we study the stark shift of binding energy for a Hydrogenic donor impurity confined within a circular quantum ring composed from three different semiconducting heterostructures AlxGa1-xN/GaN, InxGa1-xN/GaN, Ga1−xAlxAs/GaAs under the electric fields along different directions. We supplied a position-dependent electric field by using a charged rod of radius ‘a' and charge density λ. By placing the charged rod and donor impurity in different positions, we have studied the changes in the on and off-center donor binding energies, system energy levels, probability densities, average position of the electron, and the probability finding electron inside the quantum ring. We describe the redshift and blueshift of the donor impurity binding energy when different parameters change.

CdS/HgS Cylindrical Core/Shell: The simultaneous effect of the hydrostatic pressure and temperature on the diamagnetic susceptibility of hydrogenic donor impurity

One of the most important factors of controlling the properties of the above mentioned systems is hydrostatic pressure and temperature. The effect of the hydrostatic pressure and temperature on diamagnetic susceptibility and binding energy of a center hydrogenic donor impurity has been theoretically investigated in the framework of the effective mass approximation. We describe the quantum confinement by an infinite deep potential. The results for a cylindrical Inhomogeneous quantum dots made out of [CdS (Core) / HgS (Well) / CdS (Shell)] show that (i) when the hydrostatic pressure increase, the diamagnetic susceptibility decreases and the binding energy increases. (ii) The diamagnetic susceptibility increases with the temperature.

The External Electric and Magnetic Fields Effect on Binding Energy of Hydrogenic Donor Impurity in a InGaAsP/InP Core–Shell Quantum Dot

The External Electric and Magnetic Fields Effect on Binding Energy of Hydrogenic Donor Impurity in a InGaAsP/InP Core–Shell Quantum Dot

Magnetic properties of GaAs parabolic quantum dot in the presence of donor impurity under the influence of external tilted electric and magnetic fields

The dependence of the magnetization and magnetic susceptibility of donor impurity in parabolic GaAs (Gallium Arsenide) quantum dot has been investigated, at finite temperature under the influence of external tilted electric and magnetic fields. Based on the effective mass approximation, the Hamiltonian of an electron confined in a parabolic quantum dot in the presence of donor impurity which is presented in electric and magnetic fields has been solved by employing the numerical diagonalization method of the Hamiltonian matrix. All the energy matrix elements have been obtained in analytical form. We have shown the variations of the statistical energy and binding energy of donor impurity with the electric and magnetic field strengths and tilt electric field angle. The computed results show that the electrical field can tune the magnetic properties of the QD GaAs medium by flipping the sign of its magnetic susceptibility from diamagnetic (χ < 0) to paramagnetic (χ > 0).

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

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.

Hydrogenic donor impurities in -doped cylindrical quantum dots under intense laser field

A theoretical study of the effects of non-resonant intense laser field on the donor impurity binding energy in a cylindrical quantum dot with -doped axial potential is performed in the framework of the effective mass approximation. The obtained results indicate that, 2D impurity concentration and intense laser field intensity have a significant effect on the impurity binding energy and energy levels of electrons in the cylindrical quantum dots with -type axial potential.

The Binding Energy of Impurities in the Asymmetrical Semi-Exponential Quantum Wells

Within the framework of effective-mass and envelope wave function approach, using a variational method, we have investigated the binding energy of shallow-donor impurities in an asymmetrical semi-exponential quantum wells (ASEQW). The obtained numerical results show that the structure parameters (σ and, V0) lead to significant changes in the impurity binding energy. Furthermore, these results show that the hydrogenic donor impurity binding energy may be increased or decreased as a function of the impurity position in quantum well.