Hydrogen chemisorption on the GaAs (111)A Ga surface is investigated under atmospheric pressure using an in situ optical monitoring system which consists of GaAs halogen transport atomic layer epitaxy (ALE) and surface photoabsorption (SPA) systems. The results of the in situ monitoring indicate the existence of a stable hydrogen-terminated surface. It is shown that hydrogen in the carrier gas reacts dissociatively with the (111)A Ga surface, and the relationship between the surface hydrogen coverage and hydrogen partial pressure is explained well by the Langmuir isotherm with dissociation. Atomic configuration on the surface is examined further by means of ab initio molecular dynamics calculation. The total energy change due to the calculated process is very close to the standard enthalpy of adsorption obtained by the experiment.
|Number of pages||6|
|Journal||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|Publication status||Published - 2000 Nov|
ASJC Scopus subject areas
- Physics and Astronomy(all)