Origin of the 0.97 eV luminescence in irradiated silicon

• Published in: Physica B + C 1983-02, Vol.116 (1-3), p.258-263
• Main Authors: O'Donnell, K.P., Lee, K.M., Watkins, G.D.
• Format: Article
• Language: English
• ISSN: 0378-4363
• DOI: 10.1016/0378-4363(83)90256-5

Optical detection of magnetic resonance studies are described for the well-studied optical center with zero phonon line at 0.97 eV in irradiated silicon. Analysis of the S=1 ODMR spin Hamiltonian reveals a low symmetry (Clh) center and a resolved 29Si hyperfine interaction with a single silicon atom. In a specially enriched 13C doped sample we find additional hf interactions with two equivalent carbon atoms. At elevated temperatures, the defect reorients easily from one Clh distortion to another around a common 〈111t> axis; during this reorientation the spin density remains located on the same silicon atom and the same carbon pair. From these results we construct a model comprising two adjacent (substitutional) carbon atoms and an interstitial silicon atom which has distorted out from a bond-centered position. We conclude that the same defect gives rise to the Si-G11 EPR spectrum when positively charged.