Screening phenomena at the interface between a ferroelectric (FE) and an electrode are of great interest both from a fundamental point of view and for potential applications using a FE layer (FeRAM, FE tunnel junctions). In this thesis, we used photoemission-based techniques to study several screening phenomena on FE perovskites. Firstly, PhotoElectron Emission Microscopy (PEEM) experiment revealed a FE monodomain to stripe-domains transition in ultrathin film of BiFeO3 when reducing film thickness. Still by using PEEM, we carried out a quantitative investigation of oxygen vacancies as internal screening in BaTiO3 single crystals. Secondly, we used x-ray photoemission spectroscopy (XPS) with in-situ applied bias to investigate the electronic properties electrode/BaTiO3 interfaces and measure the polarization-induced band shifts.
