Due to their interesting optical and electronic properties, silicon nanocrystals (Si NCs) were the subject of an intense research activity. The definition of their electronic structure is not trivial, neither from a theoretical nor from and experimental point of view. In fact, the models and methodologies developed for bulk material cannot be directly applied to study these nanostructures where size-related effects, like quantum confinement (QC) and surface related phenomena, play a major role. In this work, X-ray Photoelectron Spectroscopy …