First-principles study of the effects of interface structure on the Schottky barrier height of the GaAs(110)/Al interface

The relaxed atomic structures, energies, and Schottky barrier heights of six translation states of the Al-GaAs(110) interface are calculated using a first-principles pseudopotential technique. The Schottky barrier height varies by 0.7 eV depending on the translation state, even though the energies of the structures are very similar. The lowest-energy translation state, which has not been considered in any previous studies, is the only one which allows every interface atom to participate in bonding across the interface. For each of the unrelaxed interface structures the Fermi level is pinned very close to the local charge neutrality level.