Effect of impurity position and electric field on the optical absorption coefficients and oscillator strength in spherical multilayer quantum dot

In this paper, in the effective mass approximation, we have investigated the effects of the impurity position, external electric field, and the structure sizes on the linear, third-order nonlinear, and total intersubband optical absorption coefficients and oscillator strength of a spherical multilayer quantum dot. In addition, we have examined the variation of the maximum of the total absorption coefficient and the resonance energy versus the core radius, shell thickness, well width, and the applied electric field. The initial and final states' wave functions and their associated eigenvalues have been determined by solving the Schrodinger equation of the system using the two-dimensional finite difference method. It is found that the existence of an impurity, as well as its position and the applied electric field has a considerable influence on the optical absorption coefficients and oscillator strength. Furthermore, our results show that the structure sizes (core radius, shell thickness, well width) have a considerable effect on the maximum of the total absorption coefficient and the resonance energy.