Atom-selective imaging of the GaAs(110) surface

Abstract

We report the first voltage-dependent scanning tunneling microscope images of a compound semiconductor surface, GaAs(110). Images show either only Ga atoms, or only As atoms, depending on the bias voltage. By combining voltage-dependent images with theoretical calculations, we quantitatively determine surface structural parameters which cannot be inferred from the images alone. © 1987 The American Physical Society.