Adsorption and reaction processes of physisorbed molecular oxygen on Si(111)-(7×7)
2005 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 72, no 7, 075346- p.Article in journal (Refereed) Published
The adsorption and reaction processes of physisorbed oxygen molecules on a Si(111)-(7×7) surface have been investigated using time-resolved O 1s core-level photoemission measurements at 45 K. Physisorbed oxygen molecules are only observed at 45 K and lower temperatures on a Si(111)-(7×7) surface. At the dosage when the dangling bonds are saturated by chemisorbed oxygen, the coverage of the physisorbed species increases drastically. This result indicates that oxygen species, which are chemisorbed on top of adatoms, modifies the potential energy curve for an oxygen molecule approaching the surface such that physisorbed oxygen molecules are stabilized. Further, the longer lifetime at a higher dosage indicates that an intermolecular force plays a role for the stabilization of this species. Taking these results into account, an oxidation stage-dependent gas-surface interaction for an oxygen molecule approaching the Si(111) surface is suggested.
Place, publisher, year, edition, pages
2005. Vol. 72, no 7, 075346- p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-50437DOI: 10.1103/PhysRevB.72.075346ISI: 000231564500133OAI: oai:DiVA.org:liu-50437DiVA: diva2:271333