Influence of image charges on the impurity-related optical properties of near-surface quantum wells under a transverse electric field

The simultaneous effects of an external electric field and image charges on the hydrogen-like impurity-related optical properties of a GaAs/AlGaAs near-surface quantum well with a parabolic potential have been investigated. The oscillator strengths and the linear and the third-order nonlinear optical absorption coefficients have been investigated as the functions of incident photon energy, impurity position, and electric field strength. Numerical results show that the inclusion of image charges leads to an increase in the oscillator strength of about two times for the system under study. This effect is especially notable for large values of an electric field. It is also shown that the influence of image charges leads to a blue shift and a significant increase in peak values of the total absorption coefficient. Our results show a remarkable dependence of optical properties on both the electric field and the impurity position. We believe that a significant increase in the optical characteristics of near-surface quantum wells due to the influence of image charges should be taken into account in future developments.