LOW-ENERGY PHOTOELECTRON DIFFRACTION OF GA 3D CORE LEVELS IN GAP(110), GAAS(110) AND GASB(110)

Photoelectron diffraction pattern from Ga 3d core level photoemission have been recorded for various III-V (110) semiconductor surfaces (GaP , GaAs, GaSb) at low photon energies (40-90 eV) for the first time, Th e resolved bulk and surface contributions exhibit strong dependence on photon energy and emission direction reflecting the different atomic environment associated with surface and bulk emitters. The observed an isotropies are quite distinct for each compound. They are more pronoun ced for compounds with constituents of different scattering properties like GaSb and less for those with similar ones like GaAs. The experim ental results are compared to calculations within a multiple-scatterin g cluster model including spherical-wave corrections in order to study the surface relaxation.