VALENCE-BAND STATES OF H-GAAS(110)

The two-dimensional surface electronic band structure of H:GaAs(110) is studied by angular resolved ultraviolet photoemission spectroscopy along the XBAR'-MBAR and XBAR-MBAR symmetry lines and in the high symmetry points of the surface Brillouin zone. Three surface state bands are resolved in the first 5 eV below the upper valence band edge. A comparison with theoretical band structure calculations yields a satisfactory agreement, giving evidence of hydrogen induced GaAs(110) surface derelaxation. The clean GaAs(110) surface electronic band structure is studied comparing results with available theoretical and experimental data.