Hydrostatic pressure effects on donor-related absorption spectra in GaAs–Ga 1−xAl xAs quantum wells

Abstract

In this paper, the effects of hydrostatic stress on the density of donor impurity states and donor-related optical absorption spectra in a GaAs–Ga 1− x Al x As quantum wells are obtained. We calculate the shallow-donor binding energy for different well widths and different values of hydrostatic stress. We find that for large well widths the binding energy increases slowly with hydrostatic stress, as opposed to the behavior of the binding energy for wells with small width. One of the results shows that the binding energy does not change appreciably with the impurity position when the width of the well is small and the hydrostatic stress is high. Two structures in both, the density of states and the optical absorption spectra, associated with impurities located close to the center and to the edges of the structure, are obtained. We have also observed that the density of states and the optical absorption spectra depend strongly on the applied hydrostatic stress.