title: Manipulating the orientation of an organic adsorbate on silicon: a NEXAFS study of acetophenone on Si(0 0 1).
abstract: We investigate the chemical and structural configuration of acetophenone on Si(0 0 1) using synchrotron radiation core-level spectroscopy techniques and density functional theory calculations. Samples were prepared by vapour phase dosing of clean Si(0 0 1) surfaces with acetophenone in ultrahigh vacuum. Near edge x-ray absorption fine structure spectroscopy and photoelectron spectroscopy measurements were made at room temperature as a function of coverage density and post-deposition anneal temperature. We show that the dominant room temperature adsorption structure lies flat on the substrate, while moderate thermal annealing induces the breaking of Si-C bonds between the phenyl ring and the surface resulting in the reorientation of the adsorbate into an upright configuration.
authors.affiliation: Australian Synchrotron, Clayton, VIC 3168, Australia.
authors.forename: Kane M
authors.initials: KM
authors.lastname: O'Donnell
authors.forename: Oliver
authors.initials: O
authors.lastname: Warschkow
authors.forename: Asif
authors.initials: A
authors.lastname: Suleman
authors.forename: Adam
authors.initials: A
authors.lastname: Fahy
authors.forename: Lars
authors.initials: L
authors.lastname: Thomsen
authors.forename: Steven R
authors.initials: SR
authors.lastname: Schofield