Well-size dependence of exciton blue shift in GaAs multiple-quantum-well structures

We have studied the high-energy shift of excitons, observed in GaAs multiple-quantum-well structures at high exciton densities, as a function of well and barrier thickness. The magnitude of the blue shift was found to depend predominantly upon the GaAs layer thickness, increasing at smaller well sizes. This effect is discussed in terms of a quenching of long-ranged many-body Coulomb effects.