Infrared study of hydrogen adsorbed onc(2×8) and (2×6) GaAs(100)

The infrared spectra of adsorbed hydrogen and deuterium on c(2×{}8) and (2×{}6) GaAs(100) contain a series of bands from 2200 to 1200 (1600 to 1000) cm^-1 that are due to arsenic hydrides, terminal gallium hydrides, and bridging gallium hydrides (and deuterides). The latter is the first known example of bridge-bonded hydrogen on a semiconductor surface. Polarized spectra reveal that the AsH and GaH bonds orient along the [1{}10] and [110] axis, respectively. These results are consistent with a GaAs surface structure composed of As and Ga dimers with dimer bonds in the [1{}1 0] and [110] directions.