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Abstract:
GaAs(113̄)B surfaces were prepared by ion bombardment and annealing (IBA) and by molecular beam epitaxy (MBE) using a single Knudsen cell filled with GaAs. These surfaces were investigated through low-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and angle-resolved UV photoelectron spectroscopy (ARUPS) using photon energies of hv = 11.8 and 21.2 eV and synchrotron light. With both IBA and MBE, a 1 × 1 reconstructed surface was prepared which differs by a large amount of As in the surface layer. For the MBE 1 × 1 reconstructed surface, three different surface states or resonances were found at +0.3, −0.7 and −3.5 eV with respect to the valence band maximum which are assigned to As-derived dangling bonds and back bonds. The states at + 0.3 and -0.7 eV can be quenched by H adsorption. For the n-type sample the bands are bent upwards by 0.30 V at the surface.
