Excitonic States and Related Optical Susceptibility in InN/AlN Quantum Well Under the Effects of the Well Size and Impurity Position

Based on the finite difference method, linear optical susceptibility, photoluminescence peak and binding energies of three first states of an exciton trapped by a positive charge donor-impurity ( ) confined in InN/AlN quantum well are investigated in terms of well size and impurity position. The electron, heavy hole free and bound excitons allowed eigen-values and corresponding eigen-functions are obtained numerically by solving one-dimensional time-independent Schrödinger equation. Within the parabolic band and effective mass approximations, the calculations are made considering the coupling of the electron in the n-th conduction subband and the heavy hole in the m-th valence subband under the impacts of the well size and impurity position. The obtained results show clearly that the energy, binding energy and photoluminescence peak energy show a decreasing behavior according to well size for both free and bound cases. Moreover, the optical susceptibility associated to exciton transition is strongly red-shift (blue-shifted) with enhancing the well size (impurity position).

The impurity states in InGaAsP/InP coaxial double quantum well wires with the effects of electric and magnetic fields

The hydrogen donor impurity states are calculated in [Formula: see text] coaxial double quantum well wires by the plane wave method under the theoretical framework of effective mass envelope function approximation. The binding energies of impurity in [Formula: see text] state and [Formula: see text] state are obtained as the functions of impurity position, distance between the inner and outer quantum wires, magnetic and electric field strengths. Transition energies are calculated as the functions of impurity position, distance between the inner and outer quantum wires. The effects of quantum wire thickness and distance of quantum wires on impurity states are analyzed in detail. It is found that the effects of electric field and magnetic field on binding energy of [Formula: see text] state are different for impurity located at different positions.

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.

Impurity position effect on the diamagnetic susceptibility of a magneto-donor in GaAs inhomogeneous quantum dots

Inhomogeneous Quantum Dot (IQD) semiconductor represents a newest trend in condensed matter, due to their important quantum levels and the outstanding properties. In this work, the impurity position effect on the diamagnetic susceptibility of a shallow magneto-donor, confined to move in (IQD) made out of Ga1-xAlxAs / GaAs/ Ga1-xAlxAs is reported theoretically. With the increase of the magnetic field, the diamagnetic susceptibility increases. The results using variational method reveal that diamagnetic susceptibility depends on many parameters including the impurity position, the external magnetic field and the nanostructure size. The magnetic field effect is more pronounced when the donor is placed near the extremities of the spherical layer (off-center). In addition, a maximum of diamagnetic susceptibility is observed, corresponding to a critical position value, for strong confinement regime and when the impurity is located in the spherical layer center.

Electronic Properties of WS2/WSe2 Heterostructure Containing Te Impurity: The Role of Substituting Position

An impact of positions of Te atoms substituting W atoms in two-dimensional WS2/WSe2 heterostructures on their electronic properties is investigated by theoretical simulation. The substitution of W by Te tends to reduce the energy band gap and can lead to metallic properties depending on the impurity position and concentration.

An investigation on the effect of impurity position on the binding energy of quantum box under electric field with pressure and temperature

In the present study, we have studied theoretically the influences of donor impurity position on the binding energy of a GaAs cubic quantum box structure. The binding energy is calculated as functions of the position of impurity, electric field, temperature and hydrostatic pressure. The variational method is employed to obtain the energy eigenvalues of the structure in the framework of the effective mass approximation. It has been found that the impurity positions with electric field, pressure and temperature have an important effect on the binding energy of structure considered. The results can be used to manufacture semiconductor device application by manipulating the binding energy with the impurity positions, electric field, pressure and temperature.

External Electric Field Effect on Shallow Donor Impurity States in Zinc-Blende InxGa1−xN/GaN Symmetric Coupled Quantum Dots

Based on the effective-mass approximation and variational procedure, the ground-state donor binding energy in a cylindrical zinc-blende InxGa1-xN/GaN symmetric coupled quantum dots (SCQDs) is investigated in the presence of the external electric field. Numerical results show that the donor binding energy increases firstly until a maximum value, and then it begins to drop quickly in all the cases with decreasing the dot radius. As the thickness of left dot and right dot decreases, the donor binding energy increases monotonically at first, reaches a maximum value, and then drops rapidly for an impurity ion located at the right dot center and the middle barrier center. Moreover, the donor binding energy for an impurity ion located at the center of the left dot is insensitive to the variation of dot thickness for large dot thickness due to the Stark effect. Meanwhile, the impurity position plays an important role on the change of the donor binding energy under the external electric field. In particular, the impurity position corresponding to the peak value of the donor binding energy is shifted toward the left QD with increasing the external electric field strength.