ELECTRONIC-STRUCTURE OF PERIODICALLY DELTA-DOPED GAAS-SI

The electronic structure of periodically doped GaAs:Si systems has been self-consistently calculated with a Hedin-Lundqvist local-density functional for exchange and correlation. The influence of the periodic spacing d, the areal impurity concentration N(d), and the spread of the impurity distribution have been investigated. Miniband widths and gaps, potential-well depths, and Fermi-level position have been studied between d = 100 and 500 angstrom, thus following the transition from superlattice behavior to independent well regime. The results are used to interpret some observed photoluminescence spectra.