Observation of interface phonons by light scattering from epitaxial Sb monolayers on III-V semiconductors

Abstract
Vibrations of Sb on (110) surfacesof III-V semiconductors (InP,GaAs,GaP) were investigated by Raman scattering from the submonolayer range up to a few monolayers. Interface phonons, involving the epitaxial first monolayer of Sb and the upper substrate layer, are observed. They are clearly identified by their coverage dependence. The peaks are most pronounced for Sb on InP. They fulfill the polarization selection rules for Sb chains along (11¯0). Moreover, they reveal that for thicker Sb coverages the epitaxial structure of the first Sb monolayer remains intact.