Effects of electric field and image charges on the impurity-related optical absorption coefficients in a spherical quantum dot

The influence of an image charge effect on the impurity-related energies, the oscillator strengths of transitions from the $1s$-like state to $2p_x$ and $2p_z$ states as well as the optical absorption coefficients in a spherical quantum dot in the presence of an external electric field have been studied. The results show that the image charges lead to significant changes in the optical coefficients of the system.