0000000000648693

AUTHOR

Louis F. J. Piper

showing 4 related works from this author

Electronic structure of single-crystal rocksalt CdO studied by soft x-ray spectroscopies andab initiocalculations

2008

Soft x-ray emission spectroscopy (XES) and x-ray absorption spectroscopy (XAS) are employed to investigate the occupied and unoccupied electronic structures in rocksalt-phase single-crystal CdO. Resonant XES at the OK edge reveals a clear Cd 4d-O 2p hybridized peak and momentum-dependent coherent contributions to the resonant emission spectra. Good agreement is obtained between the above-threshold XES and XAS spectra, and the calculated O 2p local partial density of states (PDOS). Calculation of the O 2p PDOS was performed within the GW framework of many-body perturbation theory.

X-ray absorption spectroscopyMaterials scienceAbsorption spectroscopyAb initio quantum chemistry methodsAstrophysics::High Energy Astrophysical PhenomenaElectronic structureEmission spectrumPerturbation theoryAtomic physicsCondensed Matter PhysicsSingle crystalSpectral lineElectronic Optical and Magnetic MaterialsPhysical Review B
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Observation of quantized subband states and evidence for surface electron accumulation in CdO from angle-resolved photoemission spectroscopy

2008

The electronic structure of well-ordered single-crystal thin films of CdO100 has been studied using angleresolved photoemission spectroscopy. Quantized electron subbands are observed above the valence-band maximum. The existence of these states provides evidence of an intrinsic electron accumulation space-charge layer near the CdO surface, an interpretation supported by coupled Poisson-Schrodinger calculations. The origin of the accumulation layer result is discussed in terms of the bulk band structure of CdO calculated using quasiparticle-corrected density-functional theory, which reveals that the conduction-band minimum at the Brillouin-zone center lies below the charge neutrality level.

Materials scienceCondensed matter physicsPhotoemission spectroscopyInverse photoemission spectroscopyAngle-resolved photoemission spectroscopyElectronElectronic structureThin filmCondensed Matter PhysicsElectronic band structureLayer (electronics)Electronic Optical and Magnetic MaterialsPhysical Review B
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Ab-Initio Studies of Electronic and Spectroscopic Properties of MgO, ZnO and CdO

2008

We present ab-initio calculations of excited-state properties within single-particle and two-particle approaches in comparison with corresponding experimental results. For the theoretical treatment of the electronic structure, we compute eigenvalues and eigenfunctions by using a spatially nonlocal exchange-correlation potential. From this starting point, quasiparticle energies within the fully frequency-dependent G(0)W(0) approximation are obtained. By solving the Bethe-Salpeter equation, we evaluate optical properties, including the electron-hole attraction and the local-field effects. The results are compared with experimental spectra from soft X-ray emission, as well as from X-ray photoe…

PhysicsAbsorption edgeAb initio quantum chemistry methodsEllipsometryQuasiparticleAb initioDensity of statesGeneral Physics and AstronomyDensity functional theoryElectronic structureAtomic physics
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X-ray photoemission studies of the electronic structure of single-crystalline CdO(100)

2007

The electronic structure of single-crystalline CdO is investigated using X-ray photoemission spectroscopy. The surface is prepared by in situ Ar+ ion bombardment and annealing (IBA). The core level spectra before and after the IBA are presented, and reveal a dramatic reduction in the surface contamination. The semi-core Cd 4d level and valence band region following the IBA are also shown. The surface Fermi level is pinned 1.3 +/- 0.10 eV above the valence band maximum. (c) 2007 Elsevier Ltd. All rights reserved.

Materials sciencePhotoemission spectroscopyAnnealing (metallurgy)Fermi levelInverse photoemission spectroscopyAnalytical chemistryAngle-resolved photoemission spectroscopyElectronic structureCondensed Matter Physicssymbols.namesakechemistry.chemical_compoundX-ray photoelectron spectroscopychemistrysymbolsCadmium oxideGeneral Materials ScienceElectrical and Electronic EngineeringAtomic physicsSuperlattices and Microstructures
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