  A systematic treatment of graphene-semiconductor junction is presented.
Finite density of states at the Fermi level of graphene leads to exotic
electronic properties at graphene-semiconductor interface. Quite generally, the
Schottky-Mott limit and the sum rule of barrier heights are violated due to the
internal potential of graphene. By merging the principal characteristics of
semiconductor-semiconductor and metal-semiconductor junctions, the
graphene-semiconductor contact may be considered as an archetype of
unprecedented \emph{semimetal-semiconductor junction}. Generalized interface
equations disclose the coupling of junction characteristics with the density of
charge carriers in graphene. It will be shown that the well-known effect of
tunable barrier height is directly related to the junction capacitance.
Furthermore, the relative impact of image-force effect in the presence of
barrier tunability is investigated. Experimental methods to gain built-in
potential, barrier height, and capacitance of the junction are discussed in
detail. Also the development of strong inversion layer at the interface of
graphene-silicon samples is uncovered by analyzing experimental data.
