Atomic and Electronic Structure of p (1 × 1) Overlayers of Sb on the (110) Surfaces of III-V Semiconductors

The prediction of the atomic geometries of overlayers for compound semiconductors is a topic of considerable current interest, especially with regard to the mechanisms of Schottky barrier formation and the growth (e.g., by molecular-beam epitaxy) of multilayer heterojunction systems [50.1]. Moreover, such geometries are now being determined experimentally, for example by elastic low-energy electron diffraction (ELEED) intensity analyses [50.2, 3]. Thus, an opportunity exists to develop and test predictive models of the geometrical and electronic structure of ordered overlayers on semiconductor surfaces. In this contribution we present a tight-binding calculation of the atomic geometries and surface-state eigenvalue spectra of p(l × 1) overlayers of Sb on the (110) surfaces of III-V semiconductors which predicts accurately the measured structures and surface-state spectra of these surfaces. The particular systems which we examined are ordered (l × l) saturated monolayers of Sb on the (110) surfaces of GaP, GaAs, GaSb, InP, InAs and InSb. A schematic diagram of the experimental surface atomic geometry is given in Fig.50.1.