Modelling energy level alignment at organic interfaces and density functional theory

A review of our theoretical understanding of the band alignment at organic interfaces is presented with particular emphasis on the metal/organic (MO) case. The unified IDIS (induced density of interface states) and the ICT (integer charge transfer) models are reviewed and shown to describe qualitatively and semiquantitatively the barrier height formation at those interfaces. The IDIS model, governed by the organic CNL (charge neutrality level) and the interface screening includes: (a) charge transfer across the interface; (b) the "pillow'' (or Pauli) effect associated with the compression of the metal wavefunction tails; and