BOUND EXCITON RECOMBINATION IN HIGHLY Cu-DOPED ZnTe.

Most defects in semiconductors are able to bind excitons. In the case of low doping levels the bound excitons (BE:s) may be treated as non-interacting localized excitations, even though the BE wave function may be quite extended in space. A higher doping level may influence BE spectra in several ways, as discussed in this contribution. A trivial effect is that high doping usually leads to the formation of complex associates involving the dopant atoms, in addition to the simple substitutional defects dominating at low doping levels. Often a large number of such complex BE spectra are present simultaneously in optical spectra.