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Title: Adsorption and dissociation of oxygen molecules on Si(111)-(7×7) surface

The adsorption and dissociation of O{sub 2} molecules on Si(111)-(7×7) surface have been studied by first-principles calculations. Our results show that all the O{sub 2} molecular species adsorbed on Si(111)-(7×7) surface are unstable and dissociate into atomic species with a small energy barrier about 0.1 eV. The single O{sub 2} molecule adsorption tends to form an ins×2 or a new metastable ins×2* structure on the Si adatom sites and the further coming O{sub 2} molecules adsorb on those structures to produce an ad-ins×3 structure. The ad-ins×3 structure is indeed highly stable and kinetically limited for diving into the subsurface layer to form the ins×3-tri structure by a large barrier of 1.3 eV. Unlike the previous views, we find that all the ad-ins, ins×2, and ad-ins×3 structures show bright images, while the ins×2*, ins×3, and ins×3-tri structures show dark images. The proposed oxidation pathways and simulated scanning tunneling microscope images account well for the experimental results and resolve the long-standing confusion and issue about the adsorption and reaction of O{sub 2} molecules on Si(111) surface.
Authors:
;  [1]
  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
Publication Date:
OSTI Identifier:
22251390
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 139; Journal Issue: 19; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADSORPTION; DISSOCIATION; MOLECULES; OXIDATION; OXYGEN; SCANNING TUNNELING MICROSCOPY; SIMULATION; SURFACES