Green function approach to realistic calculations of the electronic structure of semiconductor interfaces

A new method for realistic calculations of the electronic structure of semiconductor interfaces is proposed, which is able to deal with the semi-infinite geometry of the system avoiding the use of repeated slab schemes. The matching formalism due to Garcia-Moliner and Rubio is exploited in order to obtain an explicit expression of the interface Green function on a localized orbital basis set in terms of the bulk band structure of the two component materials. The self-consistency loop scheme based on the Dyson equation — and already successfully applied to the case of defects in semiconductors — is then reformulated in order to treat both the short-range and the long-range (dipole layer) terms in the potential rearrangement. An example is briefly discussed to show that the numerical work required in this procedure is manageable.