Two centers were detected, in hydrogenated S-doped material, by using electron paramagnetic resonance techniques. Both defects were very similar, and had trigonal symmetry. In order to increase the resolution of the spectra, the field-scanned electron nuclear double resonance method was used. The ratio of the intensities of the spectra remained the same after various quenching procedures. This suggested that their formation had almost the same relative probability. Isotopically enriched S was used, and revealed the involvement of one S atom in each center. In electron nuclear double resonance hyperfine interactions with H, one atom per center was observed. Further evidence for the involvement of H in these defects was found by doping with D. On the basis of the experimental evidence, the defects were identified as being 2 forms of a substitutional S double donor in the neutral charge state; passivated by a single H atom. That is, (S-H)0 pairs. This identification was supported by infra-red absorption data.

I.S.Zevenbergen, T.Gregorkiewicz, C.A.J.Ammerlaan: Physical Review B, 1995, 51[23], 16746-9