Matériau 2D pour les sources optiques de nouvelle génération

Abstract

In this master’s thesis, we calculated the structural, electronic and Diachalcogenide transition metal optics in its two-dimensional (2D) form. THE calculations were performed by simulation using the VASP code, which uses the Density Functional theory (DFT), in the Gene- ralized Gradient Approximation (GGA) of exchange-correlation po- tential for their two parametrization PBE and HSE06. MoSe2 and WSe2 has been experimentally exfoliated from its crystalline three- dimensional form . We theoretically calculated the lattice parameter a of our two-dimensional structure and we showed that it agrees with the experimental parameter. For the electronic properties, we calcula- ted the band structures, the total and partial density of states. we showed in particular that our material is a direct gap semiconductor. Due to their gap energy, the materials are useful in the photovoltaic field. Finally, we studied the optical properties of our material for in- cident photons. We have calculated the real and imaginary parts of the dielectric function as well as their absorbance.