  In the past decade graphene has been one of the most studied material for
several unique and excellent properties. Due to its two dimensional nature,
physical and chemical properties and ease of manipulation, graphene offers the
possibility of integration with the exiting semiconductor technology for
next-generation electronic and sensing devices. In this context, the
understanding of the graphene/semiconductor interface is of great importance
since it can constitute a versatile standalone device as well as the
building-block of more advanced electronic systems. Since graphene was brought
to the attention of the scientific community in 2004, the device research has
been focused on the more complex graphene transistors, while the
graphene/semiconductor junction, despite its importance, has started to be the
subject of systematic investigation only recently. As a result, a thorough
understanding of the physics and the potentialities of this device is still
missing. The studies of the past few years have demonstrated that graphene can
form junctions with 3D or 2D semiconducting materials which have rectifying
characteristics and behave as excellent Schottky diodes. The main novelty of
these devices is the tunable Schottky barrier height, a feature which makes the
graphene/semiconductor junction a great platform for the study of interface
transport mechanisms as well as for applications in photo-detection, high-speed
communications, solar cells, chemical and biological sensing, etc. In this
paper, we review the state-of-the art of the research on graphene/semiconductor
junctions, the attempts towards a modeling and the most promising applications.
