Tunneling microscopy and spectroscopy of molecular beam epitaxy grown GaAs-AlGaAs interfaces

We report the first observation of GaAs/AlGaAs compound multilayers and interfaces at atomic scale resolution. Using a scanning tunneling microscope, the atomic registry in the epitaxial layers and their interfaces was observed. The semiconductor band gaps and valence-band offsets relative to the Fermi level are obtained via local spectroscopy in the GaAs and AlGaAs multilayers.