Theoretical studies of H2 desorption from Si(100)–2×1H

Abstract

Theoretical studies of H2 desorption from a cluster model of the Si(100)–2×1H surface show that the desorption pathway is symmetrical and has a desorption energy barrier of 3.75 eV and a corresponding adsorption energy barrier of 1.15 eV. The proper treatment of electron correlation lowers the desorption energy barrier considerably. The present results suggest that the desorption of two hydrogen atoms from different Si atoms of a surface dimer is not the desorption pathway observed experimentally at activation energies in the range 2.0–2.9 eV.