A model for exciton binding energies in III-V and II-VI quantum wells

We present a model for calculating exciton states in quantum wells (QWs) in which one of the two band discontinuities is large whereas the other one is arbitrary (positive, negative or zero). Exciton binding energies are calculated for ZnSe/ZnSxSe1-x, InxGa1-xAs/GaAs and GaAs/AlxGa1-xAs QWs. Good agreement with experimental results is found for all these systems. For ZnSe/ZnSxSe1-x, in which the conduction band offset is almost vanishing, the observed increase in the exciton binding energy is found to be due to the effective mass mismatch between the two materials