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

The Journal of Chemical Physics
Thomas BruhnPatrick Vogt

Abstract

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.

References

Mar 15, 1990·Physical Review. B, Condensed Matter·D K BiegelsenL Swartz
Jun 15, 1991·Physical Review. B, Condensed Matter· Le Lay GG Margaritondo
Nov 15, 1992·Physical Review. B, Condensed Matter·I M VitomirovJ M Woodall
Nov 23, 1992·Physical Review Letters·J FaltaP D Kirchner
Aug 3, 2001·Nature·R J Hamers
Nov 22, 2002·Physical Review Letters·Akihiro OhtakeAkiko Natori
Jul 13, 2004·Physical Review Letters·Akihiro OhtakeNobuyuki Koguchi
Feb 9, 2005·Physical Review Letters·Akihiro OhtakeNobuyuki Koguchi
Nov 27, 2008·Langmuir : the ACS Journal of Surfaces and Colloids·Sung-Soo BaeJeong Won Kim
Jul 19, 2008·Annual Review of Analytical Chemistry·Robert J Hamers

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