RESOLVING THE SURFACE CONTRIBUTION OF THE P L2, 3 VV AUGER LINESHAPE OF GAP(110) VIA USE OF (1 X-1) SB OVERLAYERS

An experimental and theoretical study of the band-like P L2,3VV Auger lineshape for GaP(110) is reported (kinetic energy almost-equal-to 120eV). By deposition of one monolayer of Sb (isoelectronic to P) we determine the surface-related Auger lineshape as the difference between the two spectra measured from the as-cleaved surface and the GaP/Sb interface. Theoretical calculations based on a single particle approach including different structural coordination models (i.e. ideally truncated surface, real relaxed surface, ordered Sb overlayer) are performed, which allows to isolate the surface contribution of the L2,3VV Auger profile from the bulk related lineshape. Moreover the results of the joint analysis are discussed giving excellent agreement between calculations and measurements and pointing toward an interpretation of the P LVV lineshape in terms of surface structural probe.