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First-principles surface phase diagrams reveal that epitaxial monolayer graphene films on the Si side of 3C-SiC(111) can exist as thermodynamically stable phases in a narrow range of experimentally controllable conditions, defining a path to the highest quality graphene films. Our calculations are based on a van der Waals corrected density functional. The(More)
We report quasiparticle-energy calculations of the electronic bandstructure as measured by valence-band photoemission for selected II-VI compounds and group-III-nitrides. By applying GW as perturbation to the ground state of the fictitious, non-interacting Kohn-Sham electrons of density-functional theory (DFT) we systematically study the electronic(More)
By means of quasiparticle-energy calculations in the G0W0 approach, we show for the prototypical insulator-semiconductor system NaCl/Ge(001) that polarization effects at the interfaces noticeably affect the excitation spectrum of molecules adsorbed on the surface of the NaCl films. The magnitude of the effect can be controlled by varying the thickness of(More)
We discuss density functional theory calculations of hybrid inorganic-organic systems that explicitly include the global effects of doping (i.e., position of the Fermi level) and the formation of a space-charge layer. For the example of tetrafluoro-tetracyanoquinodimethane on the ZnO(0001[over ¯]) surface we show that the adsorption energy and electron(More)
We present an improved method to calculate defect formation energies that overcomes the band-gap problem of Kohn-Sham density-functional theory (DFT) and reduces the self-interaction error of the local-density approximation (LDA) to DFT. We demonstrate for the silicon self-interstitial that combining LDA with quasiparticle energy calculations in the G0W0(More)
The structural, electronic, and optical properties of the semiconducting oxide SnO 2 are investigated using first-principles calculations. We employ the G 0 W 0 formalism based on hybrid-functional calculations to compute the quasiparticle band structure and density of states for which we find good agreement with results from photoemission and two-photon(More)
We have developed a computationally-tractable first-principles approach ͑based on density-functional and many-body perturbation theories͒ to treat the indirect absorption of light by free carriers in semiconductors and insulators and applied it to the technologically important class of group-III nitrides. Indirect absorption by free and impurity-bound(More)
Many-body perturbation theory in the GW approach is applied to lanthanide oxides, using the local-density approximation plus a Hubbard U correction (LDA+U) as the starting point. Good agreement between the G0W0 density of states and experimental spectra is observed for CeO2 and Ce2O3. Unlike the LDA+U method G0W0 exhibits only a weak dependence on U in a(More)
The long-standing problem of the oxygen self-diffusion mechanism in silicon dioxide, a prototypical oxide, both in the crystalline and in the amorphous phase, is studied from first principles. We demonstrate that the widely used local-density approximation to density functional theory (DFT) predicts a kinetic behavior of oxygen in strong disagreement with(More)