Abstract
GaAs(001) surfaces, on which epitaxial growth is most commonly performed, contain, in general, either missing dimer rows or excess As ad-dimers, and As coverage is not equal to 1.00. We investigated theoretically how the layer-bylayer growth is maintained on GaAs(001) surfaces by controlling the excess and deficiency of surface As atoms. Our calculations indicate that pre-adsorbed Ga atoms act as “self-surfactant atoms”; and induce the As rearrangement on the surface during GaAs epitaxial growth. We show that this effect originates from the energy stabilization due to the charge transfer on the surfaces.
