High-resolution mapping of deep-level photoluminescence in annealed Czochralski-grown crystals revealed, for the first time, that the D1/D2 lines at low temperatures exhibited an opposite intensity contrast around dislocations when compared with the 0.77eV band which was commonly observed at room temperature. The intensity of the D1/D2 lines decreased on dislocation lines in the same way as did the cathodoluminescence images of D1/D2 lines in plastically deformed float-zone Si crystals. The 0.77eV band was here re-named the Db band, since the peak shifted parallel to the band-gap with temperature. A positive correlation between the Db band intensity and the precipitated O concentration, and an agreement in their distributions, suggested that the Db band was associated with O precipitation. The increase in the Db band on dislocation lines was attributed to the preferential precipitation of O.

M.Tajima, M.Tokita, M.Warashina: Materials Science Forum, 1995, 196-201, 1749-54