Recombinative desorption of hydrogen from the Ge(100)–(2×1) surface: A laser-induced desorption study

Abstract

The recombinative desorption of H2 from Ge(100)–(2×1) is studied by temperature programed desorption (TPD) and laser-induced desorption (LID). In contrast to what is observed for the Si(100)–(2×1) surface, the TPD spectra for Ge(100) do not appear to show appreciable formation of a stable dihydride species. Both the TPD and LID results are consistent with the first-order recombinative desorption kinetics. Analysis of the LID results yield an activation energy, Ea=40±2 kcal/mol and preexponential factor, ν=4×1013±1 s−1. The results are discussed in terms of several mechanisms that have been proposed for the first-order recombinative desorption of hydrogen from Si(100)–(2×1).