Application of the exact exchange potential method for half metallic intermediate band alloy semiconductor

In this paper we present an analysis of the convergence of the band structure properties, particularly the influence on the modification of the bandgap and bandwidth values in half metallic compounds by the use of the exact exchange formalism. This formalism for general solids has been implemented using a localized basis set of numerical functions to represent the exchange density. The implementation has been carried out using a code which uses a linear combination of confined numerical pseudoatomic functions to represent the Kohn-Sham orbitals. The application of this exact exchange scheme to a half-metallic semiconductor compound, in particular to Ga4P3Ti, a promising material in the field of high efficiency solar cells, confirms the existence of the isolated intermediate band in this compound. (C) 2004 American Institute of Physics.