Electric-field-induced dissociation of excitons in semiconductor quantum wells

Abstract

We have calculated the effect of a constant electric field on the energy position of the exciton ground state in semiconductor single-quantum wells. We discuss only the case of quantum wells where electron and hole wave functions are mostly localized within the same layer at zero electric field (e.g., GaAs-${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Al}}_{\mathrm{x}}$As structures). In such quantum wells an electric field applied parallel to the growth axis polarizes free-electron and -hole wave functions in opposite directions and therefore weakens the excitonic binding. Our theoretical results are in qualitative agreement with recent absorption data.