Composition and Structure of β-SiC(100)-(2 × 2) Surfaces Monitored by Photoemission Spectroscopy using Synchrotron Radiation

1998 ◽  
Vol 05 (01) ◽  
pp. 213-217 ◽  
Author(s):  
L. Douillard ◽  
F. Semond ◽  
P. Soukiassian ◽  
D. Dunham ◽  
F. Amy ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Experimental Evidence ◽  
Valence Band ◽  
Surface Reconstruction ◽  
Core Level ◽  
Single Domain ◽  
Photoemission Spectroscopy ◽  
Spectral Features ◽  
Composition And Structure ◽  
Level Shifts

We investigate the single domain β-SiC(100)-(2 × 1) surface reconstruction by core level and valence band photoemission spectroscopies using synchrotron radiation. Specific spectral features at the Si 2p and C 1s core levels including bulk and surface core level shifts, and in the valence band, bring experimental evidence of reproducible β-SiC(100)-(2 × 1) structures having different Si/C compositions ranging from Si-terminated to Si- + C-containing surfaces.

HIGH RESOLUTION SYNCHROTRON RADIATION PHOTOEMISSION SPECTROSCOPY

1997 ◽  
Vol 04 (02) ◽  
pp. 287-293 ◽  
Author(s):  
G. LE LAY
Keyword(s):  
Synchrotron Radiation ◽  
Surface Science ◽  
Core Level ◽  
Silicon Surfaces ◽  
Photoemission Spectroscopy ◽  
Level Shifts ◽  
Dimensional Electron Gas ◽  
Spectroscopy Studies ◽  
Synchrotron Radiation Photoemission ◽  
Very High

Photoemission spectroscopy studies with very-high-energetic resolution at third generation synchrotron radiation facilities open up new perspectives in surface science. To illustrate this, recent advances achieved from valence band studies will be described, i.e. investigation of the quantized electronic states of a two-dimensional electron gas at the InAs(110) surface. New insights gained from core level spectroscopy in the most promising soft X-ray regime will also be presented, i.e. evidence of new spectral features in Si 2p studies of low index silicon surfaces and identification of surface core level shifts in III–V semiconductors.

HIGH RESOLUTION CORE LEVEL SPECTROSCOPY AT THE Cu/Ru(0001) INTERFACE

2002 ◽  
Vol 09 (02) ◽  
pp. 723-727 ◽  
Author(s):  
T. H. ANDERSEN ◽  
L. BECH ◽  
J. ONSGAARD ◽  
S. V. HOFFMANN ◽  
Z. LI
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Binding Energy ◽  
Energy Shift ◽  
Core Level ◽  
Photoemission Spectroscopy ◽  
Copper Adsorption ◽  
X Ray ◽  
Level Shifts ◽  
Binding Energy Shift

Copper adsorption on Ru(0001) has been studied by synchrotron radiation. The clean Ru 3d 5/2 spectra were found to consist of two components with a binding energy shift of 400 meV. The component with the lower binding energy represents the first layer of ruthenium atoms. Adsorption of copper gives rise to core level shifts of the Ru 3d 5/2 components, which were studied as a function of Cu coverage. Experiments were carried out with copper coverages varying from the submonolayer range up to two monolayers of copper. The binding energy of the Cu 2p 3/2 level was measured by X-ray photoemission spectroscopy.

Core Level Shifts and Grain Boundary Cohesion

1998 ◽  
Vol 4 (S2) ◽  
pp. 766-767
Author(s):  
D. A. Muller
Keyword(s):  
Charge Transfer ◽  
Valence Band ◽  
Core Level ◽  
Level Shift ◽  
The Core ◽  
Metallic Interfaces ◽  
Level Shifts ◽  
Electron Energy Loss ◽  
Valence Band Width

The role of core level shifts at metallic interfaces has often been ignored in electron energy loss spectroscopy (EELS) even though very small changes in bond length can lead to large core level shifts. However, the popular interpretation of core level shifts as measures of charge transfer is highly problematic. For instance, in binary alloys systems, the core level shifts can be the same sign for both atomic constituents[l]. The simple interpretation would require that both atomic species had lost or gained charge. Further, the signs of the core level shifts can be opposite to those expected from electronegativity arguments[2]. A core level shift (CLS) is still possible, even when no charge transfer occurs. As illustrated in Fig. 1, if the valence band width is increased, the position of the center of the valence band with respect to the Fermi energy will change (as the number of electrons remains unchanged).

Photoemission Results for Laser-Annealed Si(111) and Ge(111) Surfaces

1981 ◽  
Vol 4 ◽  
Author(s):  
F.J. Himpsel ◽  
D.E. Eastman ◽  
P. Heimann ◽  
B. Reihl ◽  
C.W. White ◽  
...  
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Valence Band ◽  
Surface States ◽  
Core Level ◽  
Characteristic Surface ◽  
Local Bonding

ABSTRACTWe have studied the valence band and surface-core-level states for laser-annealed, thermally-annealed, and cleaved Ge(111) and Si(l11) surfaces with high resolution photoelectronspectroscopy using synchrotron radiation. For the annealed surfaces we find two surface states near the top of the valence band as well as characteristic surface core level spectra. These indicate the existence of a common local bonding geometry for all these surfaces. We observe that the (1 × 1) and cleaved (2 × 1) surfaces are not related as recently reported for Si.

Adsorption of water on Si(001)-2 × 1 and Si(111)-7 × 7 surfaces at 90 and 300 K: A Si 2p core-level and valence band study with synchrotron radiation

1995 ◽  
Vol 338 (1-3) ◽  
pp. 143-156 ◽  
Author(s):  
Christine Poncey ◽  
François Rochet ◽  
Georges Dufour ◽  
Henri Roulet ◽  
Fausto Sirotti ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Valence Band ◽  
Core Level ◽  
Adsorption Of Water

Si 2p Core Level Shifts of the Epitaxial SiON Layer on a SiC(0001), Studied by Photoemissin Spectroscopy

2011 ◽  
Vol 675-677 ◽  
pp. 15-19 ◽  
Author(s):  
T. Shirasawa ◽  
S. Tanaka ◽  
T. Muro ◽  
Y. Tamenori ◽  
Y. Harada ◽  
...  
Keyword(s):  
Chemical Shifts ◽  
Emission Angle ◽  
Core Level ◽  
Silicon Oxynitride ◽  
Photoemission Spectroscopy ◽  
Structure Model ◽  
Epitaxial Silicon ◽  
Angle Dependence ◽  
Spectral Components ◽  
Level Shifts

The epitaxial silicon oxynitride (SiON) layer grown on a 6H-SiC(0001) surface is studied with core level photoemission spectroscopy. Si 2p spectra show three spectral components other than the bulk one. Chemical shifts and emission angle dependence of these components are well explained within a framework of a determined structure model of the SiON layer.

scholarly journals Core level shifts in Cu–Pd alloys as a function of bulk composition and structure

2015 ◽  
Vol 640 ◽  
pp. 127-132 ◽  
Author(s):  
Jacob R. Boes ◽  
Peter Kondratyuk ◽  
Chunrong Yin ◽  
James B. Miller ◽  
Andrew J. Gellman ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Core Level ◽  
Composition And Structure ◽  
Level Shifts

Computational and experimental evidence for a new TM–N3/C moiety family in non-PGM electrocatalysts

2015 ◽  
Vol 17 (27) ◽  
pp. 17785-17789 ◽  
Author(s):  
Sadia Kabir ◽  
Kateryna Artyushkova ◽  
Boris Kiefer ◽  
Plamen Atanassov
Keyword(s):  
Experimental Evidence ◽  
First Principles ◽  
Core Level ◽  
Dft Computations ◽  
Level Shifts ◽  
Formation Energies

Our DFT computations predict favourable formation energies for previously unexplored Fe–N3/C defect moieties in carbonaceous catalysts. N 1s core-level shifts were computed from first-principles for XPS fingerprinting.

scholarly journals Microscopic Views of Atomic and Molecular Oxygen Bonding with epi Ge(001)-2×1 Studied by High-Resolution Synchrotron Radiation Photoemission

2019 ◽  
Author(s):  
Yi-Ting Cheng ◽  
Hsien-Wen Wan ◽  
Chiu-Ping Cheng ◽  
Jueinai Kwo ◽  
Minghwei Hong ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Atomic Oxygen ◽  
Subsurface Layer ◽  
Core Level ◽  
Oxide Semiconductor ◽  
Mos Devices ◽  
Level Shifts ◽  
Embryo Stage ◽  
A Charge ◽  
Synchrotron Radiation Photoemission

Embryo stage of oxidation of an epi Ge(001)-2×1 by atomic oxygen and molecular O2 is studied via synchrotron radiation photoemission. The topmost surface buckled with the up- and down-dimer atoms and the first subsurface layer behave distinctly from the bulk by exhibiting surface core-level shifts in the Ge 3d core-level spectrum. The O2 molecules become dissociated upon reaching the epi Ge(001)-2×1 surface. One of the O atom removes off the up-dimer atom, and the other bonds with the underneath Ge atom in the subsurface layer. Atomic oxygen adsorbed on the epi Ge(001)-2×1 preferentially in between the up-dimer atoms and the underneath subsurface atoms without affecting the down-dimer atoms. The electronic environment of the O-affiliated Ge up-dimer atoms becomes similar to that of the down-dimer atoms. Both exhibit an enrichment in charge, where the subsurface of the Ge layer is maintained in a charge-deficient state. The dipole moment originally generated in the buckled reconstruction no longer exists, thereby resulting in a decrease in the ionization potential. The down-dimer Ge atoms and the back-bonded subsurface atoms remain inert to atomic O and molecular O2, a possible cause of low reliability in Ge-related metal-oxide-semiconductor (MOS) devices.

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