Electronic passivation of GaAs surfaces through the formation of arsenic—sulfur bonds

Abstract

X-ray photoelectron spectroscopy reveals that the remarkable electronic quality of GaAs/sulfide interfaces can be ascribed to the formation of AsxSy phases which grow on an oxide-free GaAs surface. While one of these phases is akin to As2S3, another shows significant in-plane S—S bonding. Raman experiments indicate that the band bending on this disulfide- terminated surface has been reduced to 0.12 eV.