Simultaneous effects of hydrostatic stress and an electric field on donors in a GaAs-(Ga, Al)As quantum well

Abstract

Theoretical calculations on the influence of both an external electric field and hydrostatic stress on the binding energy and impurity polarizability of shallowdonor impurities in an isolated GaAs-(Ga, Al)As quantum well are presented. A variational procedure within the effective-mass approximation is considered. The pressure-related-X crossover is taken into account. As a general feature, we observe that the binding energy increases as the length of the well decreases. For the low-pressure regime we observe a linearly binding energy behaviour. For the high-pressure regime the simultaneous effects of the barrier height and the applied electric field bend the binding energy curves towards smaller values. For low hydrostatic pressures the impurity polarization remains constant in all cases with an increasing value as the field increases. This constant behaviour shows that the small variations in well width, effective mass, and dielectric constant with pressure do not appreciably affect polarizability. For high hydrostatic pressure, we see a non-linear increase in polarizability, mainly due to the decrease of barrier height as a result of the external pressure, which allows further deformation of the impurity.

Double-Donor Energy Structure in Concentric Quantum Rings under Magnetic Field and Hydrostatic Pressure

“…For instance, a pressure P = 15 kbar lowers the ground state in comparison with the zero pressure case in ≈ 4%, whilst the pressure P = 30 kbar lowers the ground state energy in ≈ 8%. This fact seems to suggest that the D 0 2 ground state energy decreases linearly with the pressure applied on the DCQRs, which could not be surprising because a similar behavior was previously observed in quantum wells [6,12]. In order to give an answer to this suggestion, we plot the ground state energy in Fig.…”

Infinite potential barrier and hydrostatic pressure effects on impurity-related optical absorption spectra in GaAs double quantum wells

“…In order to include the pressure dependent Γ − X mixing, we have followed the phenomenological model suggested by Elabsy [5]. The trial wave function for the ground state is chosen as [6,7] …”

“…In the last years, the study of hydrostatic pressure on the optical properties of quantum confined structures have been widely investigated [1][2][3][4][5][6][7]. Even since the advent of layered semiconductor structures, one of the main research interests has been the study of the optical properties of semiconductor quantum wells (QW).…”

“…The effects of the Γ − X crossover pressure at low-temperatures on the donor binding energies in QW heterostructures have been studied by Elabsy [5]. The combined effect of hydrostatic pressure and applied electric field on the binding energy and density of shallow impurity states (DOIS) in symmetrical and asymmetrical GaAs-Ga 1−x Al x As double quantum wells (DQW) have also been calculated [6,7].…”

Effects of Dielectric Screening Function and Image Charges on Hydrogenic Donor Binding Energy in a Surface Quantum Well

“…[2][3][4][5][6][7] Several authors have reported the effect of perturbations on hydrogenic donor binding energy in different quantum wells. 8,9 Surface Quantum Well (SQW) composed of vacuum/GaAs/GaAlAs are of considerable interest due to: (1) the presence of localised states even above the single quantum barrier in the GaAlAs layer; 10 and (2) the image charges that arise from the large dielectric mismatch at the single vacuum/GaAs interface. Present authors have reported the binding energy of the excitons in such a SQW.…”