Scattering potential for interface roughness scattering

Abstract

Interface roughness scattering potential is computed for the AlAs/GaAs and Ga_0.5In_0.5P/GaAs systems by using the two models proposed in the literature: the so-called eigenvalue model and the wave function model. Potentials are found to differ by large factors for the AlAs/GaAs system, while for the Ga_0.5In_0.5P/GaAs system the difference is not very significant. Values of asperity height, Δ, and correlation length, Λ, of the roughness are also calculated for the two systems, which give agreement between theory and experiment for the wave function model. It is found that the results for the AlAs/GaAs system cannot be explained by the wave function model if the roughness protrudes into the barrier; the required values of Δ and Λ for protrusion into the well also differ from those for the eigenvalue model by large factors. For the Ga_0.5In_0.5P/GaAs wells, on the other hand, the difference in the values lies between 10 and 20%.