Origin of the D-band photoluminescence in silicon

The D-band recombination in Si is found to be independent from impurities trapped at dislocations. On the contrary, deliberate contamination of high purity Si samples which contain dislocations results in a drastic reduction of the D-band photoluminescence in the case of Fe and Cu, whereas other impurities, e.g. Ni, lead to no detectable changes in the spectrum.