The IFIGS-and-Electronegativity Concept of the Band-Structure Lineup at Semiconductor Interfaces: Application to Graphene Schottky Contacts
Winfried Mönch, Fakultät für Physik, Universität Duisburg-Essen
The band-structure lineup at semiconductor interfaces is explained by the continua of intrinsic interface-induced gap states (IFIGS) that derive from the complex band structures of the semiconductors. The barrier heights of metal-semiconductor or Schottky contacts as well as the band-edge offsets of semiconductor heterostructures are composed of a zero-charge-transfer term plus an electrostatic-dipole contribution which are determined by the branch-point energies of the semiconductors and the electronegativity difference of the two materials in contact, respectively. It will be demonstrated that the IFIGS-and-electronegativity concept rather than the Schottky-Mott rule also explains the experimental barrier heights reported for graphene Schottky contacts.