Dissociative chemisorption of hydrogen molecules on the Si(111) (1*1) surface: First-principles calculations

The dissociative chemisorption for hydrogen molecules on the Si(111) (1*1) surface has been studied using a first-principles method. A direct dissociative chemisorption process was found. The direct dissociation happens at the saddle point of the potential energy surface for hydrogen atoms moving on the Si(111) (1*1) surface. A two-dimensional potential energy surface was presented to show the direct dissociation. Different orientations of H ₂ interacting with the surface were also investigated. The calculations showed that H₂ always favours having the molecular axis parallel to the surface.