ELECTRONIC-STRUCTURE OF PERIODICALLY DELTA-DOPED GAAS-SI

The electronic structure of periodically doped GaAs:Si systems has bee n self-consistently calculated with a Hedin-Lundqvist local-density fu nctional for exchange and correlation. The influence of the periodic s pacing d, the areal impurity concentration N(d), and the spread of the impurity distribution have been investigated. Miniband widths and gap s, potential-well depths, and Fermi-level position have been studied b etween d = 100 and 500 angstrom, thus following the transition from su perlattice behavior to independent well regime. The results are used t o interpret some observed photoluminescence spectra.