A5000614005- Graphene research and applications
- Surface and Thin Film Phenomena
- Electron and X-Ray Spectroscopy Techniques
- Fullerene Chemistry and Applications
- Surface Chemistry and Catalysis
- Diamond and Carbon-based Materials Research
- Molecular Junctions and Nanostructures
- Semiconductor materials and interfaces
- Semiconductor materials and devices
- Boron and Carbon Nanomaterials Research
- Advanced Chemical Physics Studies
- Silicon Carbide Semiconductor Technologies
- Corrosion Behavior and Inhibition
- Magnetic properties of thin films
- Carbon Nanotubes in Composites
- High-Temperature Coating Behaviors
- Laser-induced spectroscopy and plasma
- Advancements in Photolithography Techniques
- Ga2O3 and related materials
- Quantum and electron transport phenomena
- Graphite, nuclear technology, radiation studies
- Silicon Nanostructures and Photoluminescence
- Ion-surface interactions and analysis
- Metal and Thin Film Mechanics
- Advanced Materials Characterization Techniques
Centre National de la Recherche Scientifique
2007-2021
Aix-Marseille Université
2005-2021
Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2008-2021
Université de Toulon
2007-2017
Forschungszentrum Jülich
2013
Institut Fresnel
2004-2010
Institut de Neurobiologie de la Méditerranée
1997-2002
Centre d’Immunologie de Marseille-Luminy
1996-1999
University of Namur
1990
When annealed at elevated temperatures under vacuum, silicon carbide surfaces show a tendency towards graphitization. Using the sensitivity of empty conduction-band states dispersion structural quality overlayer, we have used angular-resolved inverse photoemission spectroscopy (KRIPES) to monitor progressive formation crystalline graphite on $6H\ensuremath{-}\mathrm{SiC}(0001)$ surfaces. The KRIPES spectra obtained after annealing 1400 \ifmmode^\circ\else\textdegree\fi{}C are characteristic...
The electronic properties of tin dioxide single-crystalline (110) surfaces have been studied in correlation with their structure by low-energy electron diffraction, angle-integrated and resonant photoemission using synchrotron radiation [ultraviolet spectroscopy (UPS)]. Energy distribution curves were measured from the Sn 4d core levels valence band. experimental band is compared theoretical density states (DOS) perfect defective surfaces. UPS difference curves, normalized to intensity,...
Using grazing-incidence x-ray diffraction and scanning tunneling microscopy (STM), we show that the thermal decomposition of an electronic-grade wafer 6H-SiC after annealing at increasing temperatures TA between 1080 1320 °C leads to layer-by-layer growth unconstrained, heteroepitaxial single-crystalline graphite. The limited width in-plane rod profiles graphite reveals large terraces, with average size larger than 200 Å a very small azimuthal disorientation. overlayer is unstrained adopts...
Applying k-resolved inverse photoemission (KRIPES) to the √3×√3 R30°-reconstructed 6H-SiC(0001) face, we have observed a sharp surface state U located at 1.10 ± 0.05 eV above Fermi level centre of Brillouin zone. Its bandwidth 0.34 is in good agreement with 0.35 predicted by first-principle calculations based on Si-adatom model. However, LDA predict half-filled Σ1 and metallic character for this reconstruction. Together recent ARUPS data, our results reveal that one-electron band split into...
The energy dependence of the mean free path $\ensuremath{\lambda}(E)$ in graphite at low kinetic energies (below $\ensuremath{\sim}50\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$) is studied using synchrotron radiation excited Si $2p$ core level photoemission signal from a SiC substrate attenuated by an epitaxial overlayer. Diffraction structure $\ensuremath{\lambda}(E)$, appearing as strong intensity minima signal, found to reflect band gaps unoccupied states graphite. Furthermore, derived based...
The unoccupied band structure of single-crystal graphite above the vacuum level is studied by very-low-energy electron diffraction. position and dispersion three-dimensional bands coupling to vacuum, including so-called interlayer state, are determined. character prevails in bands, but quasi-two-dimensionality this layered material results their strongly non-free-electron dispersion. By comparison a state-of-art density-functional many-body calculation we identify self-energy corrections.
The geometrical, electronic, and vibrational properties of one monolayer Zinc-phthalocyanine (ZnPc) adsorbed on Ag(110) are studied by low-energy electron diffraction (LEED), scanning tunneling microscopy (STM), high-resolution energy-loss spectroscopy (HREELS). STM LEED revealed that the molecules lie flat surface, ordered in a compact arrangement with supercell defining coincidence mesh substrate lattice. By comparing HREELS spectra to those multilayer film, which weakly interacting, it...
Adsorption of organic molecules on well-oriented single crystal coinage metal surfaces fundamentally affects the energy distribution curve ultra-violet photoelectron spectroscopy spectra. New features not present in spectrum pristine can be assigned as "interface states" having some degree molecule-substrate hybridization. Here it is shown that interface states molecular orbital character easily identified at low binding isolated above featureless substrate sp-plateau. On other hand much...
We describe a simple way of producing adherent metal films (Cu or Ni) on insulator surfaces [SiO2, glass, polyphenylquinoxaline (PPQ), an insulating polymer] by electroless growth thermally activated palladium acetylacetonate [Pd(acac)2] seeding layer. Using this process, we produced tiny patterns insulators localized laser pyrolysis (using either pulsed Cu vapor cw Ar+ laser) the spun-on A tensile stress test applied to Ni deposit SiO2 reveals bonding strengths as high 2 N/mm2. The...
The natural one-dimensional corrugation of the (001) cleavage plane GeS, together with favorable lattice matching, allow successful growth oriented ${\mathrm{C}}_{60}$(111) fullerite layers, as evidenced by sharp low-energy electron diffraction patterns. ${\mathit{k}}_{\mathrm{\ensuremath{\parallel}}}$-resolved inverse photoelectron spectroscopy reveals small dispersion effects in conduction bands epitaxial multilayers at 300 K. Enhanced bandwidths are observed room temperature for one...
The electronic and magnetic properties of Mn coordinated to 1,2,4,5-tetracyanobenzene (TCNB) in the Mn-TCNB 2D metal-ligand networks have been investigated by combining scanning tunneling microscopy X-ray circular dichroism (XMCD) performed at low temperature (3 K). When formed on Au(111) Ag(111) substrates display similar geometric structures. Magnetization curves reveal ferromagnetic (FM) coupling sites with single-ion anisotropy energies, but different constants. Low-temperature XMCD...
We report a photoemission study on high-quality single-crystal graphite epitaxially grown SiC. The results are interpreted using independent information the final states obtained by very-low-energy electron diffraction. Significant intrinsic and surface effects identified, which distort response narrow observed dispersion range of $\ensuremath{\pi}$ state. assess its true model calculation. A significant dependence excited-state self-energy wave-function character is found. experimental...
We have investigated the electronic structure of two-dimensional solid solution ${\mathrm{Si}}_{x}{\mathrm{Sn}}_{1\ensuremath{-}x}/\mathrm{Si}(111)\ensuremath{-}(\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3})R30\ifmmode^\circ\else\textdegree\fi{}$ at room temperature, with a particular emphasis on empty states, using both global $[{k}_{//}$-resolved inverse photoemission spectroscopy (KRIPES)] and local probes (scanning tunneling microscopy spectroscopy, STM STS), as well DFT-LDA...
In this study synchrotron radiation was used to investigate the electronic properties of a thin film zinc-phthalocyanine (ZnPc) deposited on Si(001)-2×1 and progressively doped with K atoms. The molecular orientation probed by angular-dependent x-ray absorption spectroscopy molecules were found lie macrocycle plane roughly perpendicular surface. evolution then followed measuring photoemission spectra upon in situ evaporation atoms pristine ZnPc film. results show that doping proceeds through...
Hydrogenation of deuterium-intercalated quasi-free-standing monolayer graphene on SiC(0001) is obtained and studied with low-energy electron diffraction high-resolution energy loss spectroscopy. While the carbon honeycomb structure remains intact, it shown that a significant band gap opens in hydrogenated material. Vibrational spectroscopy evidences for hydrogen chemisorption provided its thermal stability studied.
The electronic properties of Zn-phthalocyanine vacuum deposited on Ag(110) are studied by high-resolution valence-band photoelectron spectroscopy. Submonolayer, one ordered monolayer, and molecular layers increasing thickness present spectral features that can be related to the molecule-substrate interaction as well effect overlayer escape conditions substrate photoelectrons. For first-ordered layer, an interface state a charge transfer from molecules is detected through appearance new...
In this paper it is shown that angle-resolved photoemission performed using low-energy photons on an organic-metal interface allows to clearly distinguish genuine states from features of substrate photoelectrons diffracted by the molecular lattice. As a model system ordered monolayer Zn-phthalocyanine used as diffraction lattice probe electronic band structure Ag(110) substrate. Photoemission close normal emission geometry reveals strongly dispersive absent in pristine spectra. Density...
Scanning tunneling microscopy (STM) studies of the fullerene C${}_{60}$ molecule adsorbed on silicon carbide SiC(0001)-$3\ifmmode\times\else\texttimes\fi{}3$ surface, combined with density functional theory (DFT) calculations, show that chemisorption individual molecules occurs through formation one bond to adatom only in contrast multiple other semiconducting surfaces. We observe three stable adsorption sites respect Si adatoms surface unit cell. Comprehensive DFT calculations give...
The electronic structure of a thin film chlorine-substituted Zn-phthalocyanine (ZnPcCl8) deposited on Ag(111) was studied by valence band photoemission and near-edge X-ray absorption fine spectroscopy. At the first stages molecular adsorption interface formation is accompanied promotion intense states. A charge transfer from substrate to lowest unoccupied orbital (LUMO) molecules layer appears as new density states close Fermi level in photoemission. central role LUMO corroborated reduction...