Adsorption of potassium and oxygen on GaAs(110): Charge transfer and enhanced oxidation

Abstract
The behavior of charge transfer and oxidation of GaAs(110) substrates, covered with potassium and/or oxygen, and after thermal treatment, is investigated by Auger and photoelectron spectroscopy, work-function measurements, and low-energy electron diffraction. The oxidation of GaAs(110) is efficiently promoted by the presence of K adatoms. The experimental results indicate that both the charge transfer from the K atoms to the substrate and the formation of several potassium oxides may be the crucial factors for the enhancement of the substrate oxidation.