Two surface phases of the Ga(001)-c(4 x 4) reconstruction (α, β) were prepared by molecular beam epitaxy using As4 and As2 molecular beams and the surfaces were examined by angle-resolved ultra-violet photo-electron spectroscopy and core level photo-electron spectroscopy with synchrotron radiation as the excitation source. It was demonstrated that the photo-electron spectroscopy could distinguish between the phases. Appearance of intensive surface state 0.5eV below the top of the valence band at lower energies was linked to the presence of the β-phases on the surface while in the α-phase spectra the peak was missing. Both As 3d and Ga 3d photo-electron lines show substantial differences between the phases in line shapes as well as in their deconvoluted components. The 3d data were in agreement with different surface composition and atomic structure of both phases.

Angle-Resolved Photoemission Study of Two Phases of the GaAs(100)-c(4 x 4) Surface. M.Cukr, P.Jiříček, I.Bartoš, J.Sadowski: Journal of Physics - Conference Series, 2008, 100[7], 072017 (4pp)