Abstract
A microscopic theory is applied to describe the interactions of the semiconductor electron-hole system with the quantized light field. The hierarchy of correlations involving excitons, electrons, holes, phonons and photons are described consistently using a controlled cluster-expansion approach. The results for a partly ionized plasma show that the emission at the lowest exciton resonance is relatively insensitive to the level of approximation used in the analysis since it is dominated by electron-hole-plasma contributions whereas the energetically higher luminescence is sensitive to Coulomb correlation effects.