On the binding energies of excitons in polar quantum well structures in a weak electric field

The binding energies of excitons in quantum well structures subjected to an applied uniform electric field by taking into account the exciton longitudinal optical phonon interaction is calculated. The binding energies and corresponding Stark shifts for III--V and II--VI compound semiconductor quantum well structures have been numerically computed. The results for GaAs/AlGaAs and ZnCdSe/ZnSe quantum wells are given and discussed. Theoretical results show that the exciton--phonon coupling reduces both the exciton binding energies and the Stark shifts by screening the Coulomb interaction. This effect is observable experimentally and cannot be neglected.