ADSORPTION OF MONO-VALENT METALS ON THE GaAs(110) SURFACE

We present a synchrotron radiation investigation on the electronic properties of the GaAs(110) surface covered with alkali metals (Cs, K). As and Ga core level spectra for the clean surface are compared with those obtained after metal deposition. Satellites structures at about 4 and 6 eV from the main peak are found, which can be interpreted in terms of the excitation of overlayer plasma modes. We also study comparatively the effect of K and Cs on the oxidation of the GaAs surface