Surface core-level shifts of the 3×3-Ga surface

Surface and bulk sensitive Si2p and Ga3d photoelectron spectra have been measured for the 3 × 3 -Ga surface. Only a single surface Si2p component and a single Ga3d component are found for the 3 × 3 -Ga surface from a nonlinear least-squares analysis. These findings are consistent with the threefold-hollow 1/3 ML adatom models proposed for the 3 × 3 -Ga III metal surfaces.