First-principles calculations of many-body band-gap narrowing at an Al/GaAs(110) interface

We calculate the quasiparticle electronic structure of a Al/GaAs(110) Schottky barrier as a function of distance from the interface, using the GW self-energy operator. The GaAs band gap is significantly narrowed near the metal, although the classical picture of image-potential narrowing is subject to large quantum corrections. The nature of these corrections is explored further using model calculations.