Adsorption of halogen atom (F, Cl, I) on cation-rich GaAs(001) surface

Abstract

Comparative theoretical study of halogen atom (F, Cl, I) adsorption on the cation-rich ζ-GaAs(001)-(4×2) surface was performed using projector augmented-wave (PAW) method within the density-functional theory (DFT). For all considered halogens, the energetically preferable adsorption positions are found on top sites above dimerized Ga atoms. The interaction of halogen adatom with the dimerized atoms leads to the weakening of the interfacial chemical bonds at the initial stage of surface etching. The electronic properties of the clean semiconductor surfaces and their change upon halogen adsorption are discussed.