Headline: Electrophilic surface sites as precondition for the chemisorption of pyrrole on GaAs(001) surfaces

We report how the presence of electrophilic surface sites influences the adsorption mechanism of pyrrole on GaAs(001) surfaces. For this purpose, we have investigated the adsorption behavior of pyrrole on different GaAs(001) reconstructions with different stoichiometries and thus different surface chemistries. The interfaces were characterized by x-ray photoelectron spectroscopy, scanning tunneling microscopy, and by reflectance anisotropy spectroscopy in a spectral range between 1.5 and 5 eV. On the As-rich c(4 × 4) reconstruction that exhibits only nucleophilic surface sites, pyrrole was found to physisorb on the surface without any significant modification of the structural and electronic properties of the surface. On the Ga-rich GaAs(001)-(4 × 2)/(6 × 6) reconstructions which exhibit nucleophilic as well as electrophilic surface sites, pyrrole was found to form stable covalent bonds mainly to the electrophilic (charge deficient) Ga atoms of the surface. These results clearly demonstrate that the existence of electrophilic surface sites is a crucial precondition for the chemisorption of pyrrole on GaAs(001) surfaces.

Publication Year
2015
Publication Type
Academic Articles
Citation

Bruhn, T., Fimland, B.-O., Vogt, P. (2015): Electrophilic surface sites as precondition for the chemisorption of pyrrole on GaAs(001) surfaces. - Journal of Chemical Physics, 142, p. 101903.DOI: http://doi.org/10.1063/1.4906117

DOI
10.1063/1.4906117
Links
http://publications.iass-potsdam.de/pubman/item/escidoc:1669891:3/component/esc…
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