title: Theoretical reconstruction and elementwise analysis of photoelectron spectra for imidazolium-based ionic liquids.
abstract: We have recently measured core level and valence band XPS, UPS, and MIES spectra of two room temperature ionic liquids composed of bis(trifluoromethylsulfonyl)imide anions ([Tf(2)N](-)) and either 1-ethyl-3-methyl-imidazolium ([EMIm](+)) or 1-octyl-3-methyl-imidazolium cations ([OMIm](+)). [T. Ikari, A. Keppler, M. Reinmöller, W. J. D. Beenken, S. Krischok, M. Marschewski, W. Maus-Friedrichs, O. Höfft and F. Endres, e-J. Surf. Sci. Nanotechnol., 2010, 8, 241.] In the present work we analyze these spectra by means of partial density of states (pDOS) as calculated from a single ion pair of the respective ionic liquid using density functional theory (DFT). Subsequently we reconstruct the XPS and UPS spectra by considering photoemission cross sections and analyze the MIES spectra by pDOS, which provides us decisive hints to the ionic liquid surface structure.
authors.affiliation: Institute of Physics and Institute of Micro- and Nanotechnologies, Ilmenau University of Technology, P.O. Box 100 565, 98684 Ilmenau, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Reinmöller
authors.forename: Angela
authors.initials: A
authors.lastname: Ulbrich
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ikari
authors.forename: Julia
authors.initials: J
authors.lastname: Preiss
authors.forename: Oliver
authors.initials: O
authors.lastname: Höfft
authors.forename: Frank
authors.initials: F
authors.lastname: Endres
authors.forename: Stefan
authors.initials: S
authors.lastname: Krischok
authors.forename: Wichard J D
authors.initials: WJ
authors.lastname: Beenken