Effect of the image potential on the Stark shift of exciton states in a quantum well

We consider the image potential and its effect in calculating the binding energy of the ground bound state of an exciton in a finite quantum well subjected to an external electric field by means of the variational technique. The influence of the image potential is obtained as a function of the well width, the electric-field strength, and the ratio of the dielectric constants of different media. It is found that the image-potential effect will give significant corrections to the exciton binding energy and its Stark shift. The self-image potential and mutual-image potential have opposite effects on the Stark shift.