Electronic structure of ideal metal/GaAs contacts

The electronic structure of seven ideal metal/GaAs interfaces is calculated self-consistently, within the local-density approximation. Calculated pinning positions ranged from 0.3 to 1 eV above the valence-band maximum. The metal d electorns are found to play a significant role in the electronic structure of the ideal interface, and in determining the Schottky-barrier height. These calculations contradict models that invoke intrinsic interface states to explain the experimentally observed Fermi-level pinning.