One Atomic Layer Heterointerface Fluctuations in GaAs-AlAs Quantum Well Structures and Their Suppression by Insertion of Smoothing Period in Molecular Beam Epitaxy

摘要: Photoluminescence spectra of GaAs-AlAs quantum wells are studied to evaluate the flatness heterointerfaces prepared by molecular beam epitaxy. We examine correlation interface roughness with measured intensity oscillations reflective high energy electron diffraction (RHEED) during growth. The crystal surface is found roughen after growth 10 or more atomic layers. interruption 10–100 seconds prior formation effective in achieving an atomically flat interface, leading sharp photoluminescence linewidth <30 A at 77 K even when well width reduced 40 A.