Optical detection of magnetic resonance for a deep-level defect in Silicon

Optical detection of magnetic resonance is reported for the 0.97-eV luminescence in neutron-irradiated silicon. The resonance is of an excited triplet (S=1) state of the defect, which is not the radiative state, known to be a singlet (S=0). The spectrum is unusual in that it is characteristic of a statically distorted defect (from C3v to C1h), but with residual dynamic tunneling effects where random strain stabilizes mixtures of the static C1h distortions. Vacancy-related models previously suggested for the defect are tentatively ruled out.