First-principles calculations were used to investigate the interaction of self-interstitial aggregates with the 90° partial dislocation. It was found that I4 was bound to the line, with an energy of about 3eV. The defect caused deep levels to appear in the band-gap, and optical transitions between these levels were suggested to account for luminescent bands arising from plastically deformed Si.

Optical Bands Related to Dislocations in Si. A.T.Blumenau, R.Jones, S.Oberg, T.Frauenheim, P.R.Briddon: Journal of Physics - Condensed Matter, 2000, 12[49], 10123-9