This research project is based on the application of a novel and emerging technique in surface science - Scanning Photoemission Microscopy (SPEM) - to investigate lateral variations on the submicron scale in the chemical composition and electronic structure of interfaces. It will be performed on the ESCA Microscopy beamline at the ELETTRA synchrotron radiation facility. The research work will focus on the study of binary metal layers on Si surfaces (ex.: Ag+Au/Si(111)), to explore how lateral inhomogeneities in morphology, electronic structure and Schottky barrier height can be affected by interface growth conditions, such as temperature and exposure to gases. This will provide new insight in the field of metal-semiconductor interfaces.