Surface passivation of GaAs grown on Si by selenium sulfide treatment

The improvement of the crystal quality of GaAs grown on Si after surface passivation by selenium sulfide (SeS₂) has been investigated by x-ray photoelectron spectroscopy (XPS), photoluminscence (PL) and time resloved photo-luminscence (TRPL). A simple wet chemical treatment using SeS₂ helps in the improvement of the surface properties as seen from the increase in the photoluminscence intensity and TRPL decay curve. Our results show that SeS₂ treatment can passivate the GaAs/Si surface forming ordered overlayers on it and thus giving rise to the improvement in the crystalline quality.