Pérovskites bidimensionnelles

Abstract

n this master’s thesis, we calculated the structural, electronic and optical properties of perovskite (Cs2PbI4) in its two-dimensional (2D) form. The calculations were performed by simulation using the VASP code, which uses density functional theory (DFT). The generalized gradient approximation GGA-PBE and HSE06. Perovskite Cs2PbI4 2D has been experimentally exfoliated from its three-dimensional crystalline form. We theoretically calculated the lattice parameter a of our two-dimensional structure and showed that it agrees with the experimental parameter. For the electronic properties, we calculated the structures of the bands, the total density of states and the partial densities of states and we showed in particular that our material is a direct gap semiconductor. Finally, we studied the optical proper- ties of our material. We calculated the real and imaginary parts of the complex dielectric function as well as the absorbance. The opti- cal results showed that the studied materials are good candidates for photovoltaic application in the visible and UV domain.