Vertical coupling and transition energies in multilayer InAs/GaAs quantum-dot structures

Vertically ordered quantum dots in multilayer InAs/GaAs structures have att racted large interest in recent years for device application as light emitt ers. Contradictory claims on the dependence of the fundamental transition e nergy on the interlayer separation and number of dot layers have been repor ted in the literature. We show that either a blueshift or a redshift of the fundamental transition energy can be observed in different coupling condit ions and straightforwardly explained by including strain, indium segregatio n, and electron-hole Coulomb interaction, in good agreement with experiment al results.