@article{13573,
  abstract     = {{Given the vast range of lithium niobate (LiNbO3) applications, the knowledge about its electronic and optical properties is surprisingly limited. The direct band gap of 3.7 eV for the ferroelectric phase – frequently cited in the literature – is concluded from optical experiments. Recent theoretical investigations show that the electronic band‐structure and optical properties are very sensitive to quasiparticle and electron‐hole attraction effects, which were included using the GW approximation for the electron self‐energy and the Bethe‐Salpeter equation respectively, both based on a model screening function. The calculated fundamental gap was found to be at least 1 eV larger than the experimental value. To resolve this discrepancy we performed first‐principles GW calculations for lithium niobate using the full‐potential linearized augmented plane‐wave (FLAPW) method. Thereby we use the parameter‐free random phase approximation for a realistic description of the nonlocal and energydependent screening. This leads to a band gap of about 4.7 (4.2) eV for ferro(para)‐electric lithium niobate.}},
  author       = {{Thierfelder, Christian and Sanna, Simone and Schindlmayr, Arno and Schmidt, Wolf Gero}},
  issn         = {{1610-1642}},
  journal      = {{Physica Status Solidi C}},
  location     = {{Weimar}},
  number       = {{2}},
  pages        = {{362--365}},
  publisher    = {{Wiley-VCH}},
  title        = {{{Do we know the band gap of lithium niobate?}}},
  doi          = {{10.1002/pssc.200982473}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13574,
  author       = {{Gerstmann, Uwe and Rohrmüller, M. and Mauri, F. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{157--160}},
  title        = {{{Ab initiog-tensor calculation for paramagnetic surface states: hydrogen adsorption at Si surfaces}}},
  doi          = {{10.1002/pssc.200982462}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13839,
  author       = {{Blankenburg, S. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{415--417}},
  title        = {{{Temperature dependent stability of self-assembled molecular rows}}},
  doi          = {{10.1002/pssc.200982460}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13838,
  author       = {{Sanna, Simone and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{7-8}},
  pages        = {{2272--2274}},
  title        = {{{GaN growth on LiNbO3 (0001) - a first-principles simulation}}},
  doi          = {{10.1002/pssc.200983649}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13843,
  author       = {{Wippermann, S. and Schmidt, Wolf Gero and Thissen, P. and Grundmeier, Guido}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{137--140}},
  title        = {{{Dissociative and molecular adsorption of water onα-Al2O3(0001)}}},
  doi          = {{10.1002/pssc.200982423}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13842,
  author       = {{Sanna, Simone and Gavrilenko, Alexander V. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{145--148}},
  title        = {{{Ab initio investigation of the LiNbO3(0001) surface}}},
  doi          = {{10.1002/pssc.200982456}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{13841,
  author       = {{Blankenburg, S. and Rauls, E. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{153--156}},
  title        = {{{The physics of highly ordered molecular rows}}},
  doi          = {{10.1002/pssc.200982459}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{18562,
  abstract     = {{The structural and electronic properties of strained silicon are investigated quantitatively with ab initio computational methods. For this purpose we combine densityfunctional theory within the local‐density approximation and the GW approximation for the electronic self‐energy. From the variation of the total energy as a function of applied strain we obtain the elastic constants, Poisson ratios and related structural parameters, taking a possible internal relaxation fully into account. For biaxial tensile strain in the (001) and (111) planes we then investigate the effects on the electronic band structure. These strain configurations occur in epitaxial silicon films grown on SiGe templates along different crystallographic directions.
The tetragonal deformation resulting from (001) strain induces a valley splitting that removes the sixfold degeneracy of the conduction‐band minimum. Furthermore, strain in any direction causes the band structure to warp. We present quantitative results for the electron effective mass, derived from the curvature of the conduction band, as a function of strain and discuss the implications for the mobility of the charge carriers. The inclusion of proper self‐energy corrections within the GW approximation in our work not only yields band gaps in much better agreement with experimental measurements than the localdensity approximation, but also predicts slightly larger electron effective masses.}},
  author       = {{Bouhassoune, Mohammed and Schindlmayr, Arno}},
  issn         = {{1610-1642}},
  journal      = {{Physica Status Solidi C}},
  location     = {{Weimar}},
  number       = {{2}},
  pages        = {{460--463}},
  publisher    = {{Wiley-VCH}},
  title        = {{{Electronic structure and effective masses in strained silicon}}},
  doi          = {{10.1002/pssc.200982470}},
  volume       = {{7}},
  year         = {{2010}},
}

@article{4196,
  abstract     = {{The growth of cubic group III-nitrides is a direct way to eliminate polarization effects, which inherently limit the fabrication of normally-off heterojunction field-effect transistors (HFETs) in GaN technology. HFET structures were fabricated of non-polar cubic AlGaN/GaN hetero layers grown by plasma assisted molecular beam epitaxy (MBE) on free standing 3C-SiC (001). The electrical insulation of 3C-SiC was realised by Ar+ implantation before c-AlGaN/GaN MBE. The structural properties of the epilayers were studied by highresolution x-ray diffraction (HRXRD). HFETs with normally off and normally-on characteristics were fabricated of cubic AlGaN/GaN. Capacitance-voltage (CV) characteristics of thegate contact were performed to detect the electron channel at the c-AlGaN/GaN hetero interface.}},
  author       = {{Tschumak, Elena and Lindner, Jörg and Bürger, M. and Lischka, K. and Nagasawa, H. and Abe, M. and As, Donald}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{1}},
  pages        = {{104--107}},
  publisher    = {{Wiley}},
  title        = {{{Non-polar cubic AlGaN/GaN HFETs grown by MBE on Ar+implanted 3C-SiC (001)}}},
  doi          = {{10.1002/pssc.200982615}},
  volume       = {{7}},
  year         = {{2009}},
}

@article{13580,
  author       = {{Wippermann, S. and Schmidt, Wolf Gero and Thissen, P. and Grundmeier, Guido}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{137--140}},
  title        = {{{Dissociative and molecular adsorption of water onα-Al2O3(0001)}}},
  doi          = {{10.1002/pssc.200982423}},
  volume       = {{7}},
  year         = {{2009}},
}

@article{13579,
  author       = {{Sanna, Simone and Gavrilenko, Alexander V. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{145--148}},
  title        = {{{Ab initioinvestigation of the LiNbO3(0001) surface}}},
  doi          = {{10.1002/pssc.200982456}},
  volume       = {{7}},
  year         = {{2009}},
}

@article{13577,
  author       = {{Blankenburg, S. and Rauls, E. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  number       = {{2}},
  pages        = {{153--156}},
  title        = {{{The physics of highly ordered molecular rows}}},
  doi          = {{10.1002/pssc.200982459}},
  volume       = {{7}},
  year         = {{2009}},
}

@article{13578,
  author       = {{Sanna, Simone and Gavrilenko, Alexander V. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  pages        = {{145--148}},
  title        = {{{Ab initioinvestigation of the LiNbO3(0001) surface}}},
  doi          = {{10.1002/pssc.200982456}},
  year         = {{2009}},
}

@article{13576,
  author       = {{Blankenburg, S. and Rauls, E. and Schmidt, Wolf Gero}},
  issn         = {{1862-6351}},
  journal      = {{physica status solidi (c)}},
  pages        = {{153--156}},
  title        = {{{The physics of highly ordered molecular rows}}},
  doi          = {{10.1002/pssc.200982459}},
  year         = {{2009}},
}