Déposition et étude des couches pérovskites pour le photovoltaïque.

Abstract

In recent years, hybrid organic-inorganic perovskites have emerged as a new class of semiconductors with very interesting optoelectronic properties for photovoltaic devices. This thesis focuses on the deposition of CH3NH3PbI3 perovskite materials by spin-coating on glass substrates. The effects of the nature of the solvent and the speed of rotation on the morphology of the films and the structure are studied. Two solvents are used:N, N-dimethylformamide (DMF) and a mixture of dimethylsulfoxide (DMSO) with DMF. The rotation speed varies between 700 and 2000 rpm.Scanning electron microscopy (SEM) observations indicate that the films prepared are not continuous with varying morphologies; the films are formed of elongated fibers. The structural characterization of the films revealed that the latter have a tetragonal structure of the prepared perovskite with a preferential orientation towards (110). The optical and electrical characterizations have shown that the CH3NH3PbI3 films deposited by spin coating have good optoelectronic properties. good absorbance in the visible range with an optical gap equal to1.54eV. The electrical characterizations have shown that the CH3NH3PbI3 films prepared are resistive; the thin layers of CH3NH3PbI3 turn out to be very sensitive to several factors: humidity, oxygen, light irradiation, On the other hand, the study of the heterojunction was made by the IV and CV techniques which made it possible to determine the electrical parameters heterojunction.