A REFLECTANCE ANISOTROPY SPECTROSCOPY STUDY OF GASB(100)C(2X6) SURFACES PREPARED BY SB DECAPPING

MBE-grown samples capped with a protective Sb layer were used to study clean (100) surfaces in UHV. By thermal desorption of the Sb cap laye r GaSb surfaces exhibiting c(2 X 6) reconstruction were prepared, then studied by reflectance anisotropy spectroscopy, low energy electron d iffraction and Auger electron spectroscopy. The results of this experi mental analysis allowed us to determine for the first time the surface related optical anisotropy of the c(2 X 6) reconstruction of GaSb(100 ) in the range 1.5-5.5 eV, Reflectance anisotropy spectroscopy feature s related to optical transitions of surface Sb dimers are identified a nd discussed. Moreover, the appearance of an optical anisotropy relate d to the linear electro-optic effect at the E(1) bulk critical point s hows the existence of band bending at GaSb decapped surfaces.