Schottky barrier formation of Ag on GaAs(110)

Abstract

Photoemission studies of Ag deposits on cleaved n- and p-type GaAs for coverages from ∼0.003 to 20 monolayers indicate clustered Ag growth and undetectable chemical interactions with the substrate. The position of the surface Fermi level changed throughout the deposit range. The data is inconsistent with most of the existing Schottky barrier models. The results are interpreted in terms of donor- and acceptorlike interface states which are characteristic of the clusters but modified by the screening at the interface. Values for the Schottky barrier of 0.89 eV on n-type and 0.35 eV on p-type material were obtained for the thickest coverage.