Inhomogeneous broadening arising from interface fluctuations in strained InxGa1 xAs/GaAs and (InuGa1 uAs)v(InP)1 v/InP quantum wells

The effects of inhomogeneous broadening in strained InxGa1 xAs/GaAs and (InuGa1 uAs)v (InP)1 v/InP quantum wells is studied. A theoretical model is proposed to describe the interface broadening, where the strain effects are considered by assuming a gradual interface between the different alloys. In these interfaces, we take into account the fluctuations of their thickness and position with respect to the abrupt interface picture. We build the confinement potential in the quantum well considering the effects of non-abrupt interface and we calculate the shift on the confined exciton spectra by using two numerical approaches, the effective potential and variational method. Our numerical results allows us to evaluate energies differences for the ground state of excitons higher than 49 meV, which is related to interfacial fluctuations in 50 A ° QWs, when compared with abrupt interface calculations. # 2004 Elsevier B.V. All rights reserved