Photoemission spectroscopy at MOVPE-prepared InGaAs(100) surface reconstructions

Angular resolved ultraviolet photoemission spectroscopy at BESSY was employed to study the electronic structure of the three different, (4 × 3)-, (2 × 4)-, and (4 × 2)-surface reconstructions of In_0.53 Ga_0.47As, which was grown lattice-matched to InP(100). The surfaces have been prepared using metal organic vapor phase epitaxy (MOVPE). For spectroscopy, a dedicated transfer system was employed and samples were transferred contamination-free from the MOVPE reactor to UHV-based analysis tools. For the different surface reconstructions, the Γ ? Δ ? X direction was scanned while varying the photon energy between 10 eV and 28 eV. We observed two surface states in the photoelectron spectra on all of these surface reconstructions in addition to the bulk derived valence band emissions. Different binding energies of the surface states originating from different surface band bending were detected and described.