Ce travail présente un modèle autonome et dynamique de prédiction des caractéristiques des décharges se propageant sur des surfaces isolantes polluées de manière discontinue, basé sur le bilan énergétique, les circuits électriques équivalents et les caractéristiques physiques de l'arc. Ce modèle permet de déterminer les différents paramètres de la ...
Nous présentons ici des mesures de potentiel de surface sur des plaques d'élastomères silicones vulcanisées à chaud, qui démontrent l'existence pour des champs de l'ordre de 1kV/mm de phénomènes d'injection de charge importants, et d'un transport rapide de la charge dans l'isolant, témoignant de l'absence de piégeage profond dans le matériau. Certa...
The electronic properties of wide-energy gap zinc-blende structure GaN, A1N, and their alloys Ga(1-x)A1(x)N are investigated using the empirical pseudopotential method. Electron and hole effective mass parameters, hydrostatic and shear deformation potential constants of the valence band at Gamma and those of the conduction band at Gamma and X are o...
To evaluate the dynamical effects of the screened interaction in the calculations of quasiparticle energies in many-electron systems a two-delta-function generalized plasma pole model (GPP) is introduced to simulate the dynamical dielectric function. The usual single delta-function GPP model has the drawback of over simplifications and for the crys...
We successfully applied the Green function theory in GW approximation to calculate the quasiparticle energies for semiconductors Si and GaAs. Ab initio pseudopotential method was adopted to generate basis wavefunctions and charge densities for calculating dielectric matrix elements and electron self-energies. To evaluate dynamical effects of screen...
We have applied the Green-function method in the GW approximation to calculate quasiparticle energies for the semiconductors GaP and GaAs. Good agreement between the calculated excitation energies and the experimental results was achieved. We obtained calculated direct band gaps of GaP and GaAs of 2.93 and 1.42 eV, respectively, in comparison with ...
