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Title: Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1

Abstract

Using scanning tunnelling microscopy (STM), photoelectron and photoabsorption spectroscopies, we have examined how acrylonitrile (H{sub 2}C=CH-C{identical_to}N) reacts with the Si(001)-2x1 surface for coverages ranging from {approx}10{sup 12} molecules/cm{sup 2} to {approx}10{sup 14} molecules/cm{sup 2}. At 300 K, in the very low coverage regime (below 10{sup 13} molecules/cm{sup 2}), filled- and empty-state STM images show that the molecule bridges, via its {beta} carbon and nitrogen ends, two silicon dangling bonds, across the trench separating two dimer rows. A cumulative-double-bond unit (C=C=N) is formed. The 300 K STM image results from the dynamic flipping of the molecule between two equivalent equilibrium positions, which can be seen when the molecular motion is slowed down at 80 K. For coverages larger than 10{sup 13} molecules/cm{sup 2}, for which STM does not show ordered adsorption any more, the adsorption kinetics were observed in real-time using valence band photoemission and resonant Auger yield, associated with N 1s x-ray absorption spectroscopy (NEXAFS). At 300 K, these techniques point to a situation more complex than the one explored by STM at very low coverage. Three species (cyano-bonded, vinyl-bonded, and cumulative-double-bond species) are detected. Their distribution does not vary with increasing coverage. All dimerization-related surface states are quenched atmore » saturation. The uptake rates versus coverage relationship points to the presence of a mobile precursor. Finally, the paper discusses a possible mechanism leading to the formation of cross-trench C=C=N unit at low coverage, and the reasons why the product branching ratio changes with increasing coverage.« less

Authors:
; ; ; ; ; ; ; ; ; ; ;  [1]
  1. Laboratoire de Chimie Physique Matiere et Rayonnement, Universite Pierre et Marie Curie, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)
Publication Date:
OSTI Identifier:
20666270
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 71; Journal Issue: 12; Other Information: DOI: 10.1103/PhysRevB.71.125320; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; ACRYLONITRILE; ADSORPTION; AUGER ELECTRON SPECTROSCOPY; BRANCHING RATIO; DIMERIZATION; FINE STRUCTURE; KINETICS; LAYERS; PHOTOELECTRON SPECTROSCOPY; PHOTOEMISSION; SCANNING TUNNELING MICROSCOPY; SEMICONDUCTOR MATERIALS; SILICON; SURFACES; X-RAY SPECTRA; X-RAY SPECTROSCOPY

Citation Formats

Rangan, S, Kubsky, S, Gallet, J -J, Bournel, F, Le Guen, K, Dufour, G, Rochet, F, Funke, R, Kneppe, M, Piaszenski, G, Koehler, U, Sirotti, F, Fakultaet fuer Physik und Astronomie, Institut fuer Experimentalphysik IV/AG Oberflaechenphysik, Ruhr-Universitaet Bochum, NB 4/166, D-44780 Bochum, and Laboratoire pour l'Utilisation du Rayonnement Electromagnetique, Centre Universitaire Paris-Sud, Batiment 209D, 91405 Orsay Cedex. Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1. United States: N. p., 2005. Web. doi:10.1103/PhysRevB.71.125320.
Rangan, S, Kubsky, S, Gallet, J -J, Bournel, F, Le Guen, K, Dufour, G, Rochet, F, Funke, R, Kneppe, M, Piaszenski, G, Koehler, U, Sirotti, F, Fakultaet fuer Physik und Astronomie, Institut fuer Experimentalphysik IV/AG Oberflaechenphysik, Ruhr-Universitaet Bochum, NB 4/166, D-44780 Bochum, & Laboratoire pour l'Utilisation du Rayonnement Electromagnetique, Centre Universitaire Paris-Sud, Batiment 209D, 91405 Orsay Cedex. Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1. United States. https://doi.org/10.1103/PhysRevB.71.125320
Rangan, S, Kubsky, S, Gallet, J -J, Bournel, F, Le Guen, K, Dufour, G, Rochet, F, Funke, R, Kneppe, M, Piaszenski, G, Koehler, U, Sirotti, F, Fakultaet fuer Physik und Astronomie, Institut fuer Experimentalphysik IV/AG Oberflaechenphysik, Ruhr-Universitaet Bochum, NB 4/166, D-44780 Bochum, and Laboratoire pour l'Utilisation du Rayonnement Electromagnetique, Centre Universitaire Paris-Sud, Batiment 209D, 91405 Orsay Cedex. Tue . "Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1". United States. https://doi.org/10.1103/PhysRevB.71.125320.
@article{osti_20666270,
title = {Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1},
author = {Rangan, S and Kubsky, S and Gallet, J -J and Bournel, F and Le Guen, K and Dufour, G and Rochet, F and Funke, R and Kneppe, M and Piaszenski, G and Koehler, U and Sirotti, F and Fakultaet fuer Physik und Astronomie, Institut fuer Experimentalphysik IV/AG Oberflaechenphysik, Ruhr-Universitaet Bochum, NB 4/166, D-44780 Bochum and Laboratoire pour l'Utilisation du Rayonnement Electromagnetique, Centre Universitaire Paris-Sud, Batiment 209D, 91405 Orsay Cedex},
abstractNote = {Using scanning tunnelling microscopy (STM), photoelectron and photoabsorption spectroscopies, we have examined how acrylonitrile (H{sub 2}C=CH-C{identical_to}N) reacts with the Si(001)-2x1 surface for coverages ranging from {approx}10{sup 12} molecules/cm{sup 2} to {approx}10{sup 14} molecules/cm{sup 2}. At 300 K, in the very low coverage regime (below 10{sup 13} molecules/cm{sup 2}), filled- and empty-state STM images show that the molecule bridges, via its {beta} carbon and nitrogen ends, two silicon dangling bonds, across the trench separating two dimer rows. A cumulative-double-bond unit (C=C=N) is formed. The 300 K STM image results from the dynamic flipping of the molecule between two equivalent equilibrium positions, which can be seen when the molecular motion is slowed down at 80 K. For coverages larger than 10{sup 13} molecules/cm{sup 2}, for which STM does not show ordered adsorption any more, the adsorption kinetics were observed in real-time using valence band photoemission and resonant Auger yield, associated with N 1s x-ray absorption spectroscopy (NEXAFS). At 300 K, these techniques point to a situation more complex than the one explored by STM at very low coverage. Three species (cyano-bonded, vinyl-bonded, and cumulative-double-bond species) are detected. Their distribution does not vary with increasing coverage. All dimerization-related surface states are quenched at saturation. The uptake rates versus coverage relationship points to the presence of a mobile precursor. Finally, the paper discusses a possible mechanism leading to the formation of cross-trench C=C=N unit at low coverage, and the reasons why the product branching ratio changes with increasing coverage.},
doi = {10.1103/PhysRevB.71.125320},
url = {https://www.osti.gov/biblio/20666270}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 12,
volume = 71,
place = {United States},
year = {2005},
month = {3}
}