Optical properties of the GaAs(001)-c(4x4) surface: direct analysis of the surface dielectric function

摘要

We present a systematic analysis of the reflectance anisotropy (RA) spectrum of the GaAs(001)-c(4 x 4) surface. In contrast to previous studies where RA spectra were resolved in real space by means of a layer-by-layer decomposition, we examine directly the more physically accessible surface dielectric function anisotropy. The method gives immediate information about the origin of structures in the RA spectrum, easily distinguishing between adsorptive and dissipative effects. A detailed explanation of the origin of bulk-related features in the RA spectrum of this surface is also presented. Further evidence is provided of the existence of a c(4 x 4) reconstruction featuring mixed Ga-As dimers in the top layer. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.