It was noted that the H passivation of S double donors led to the formation of 2 new centers, NL54 and NL55, as detected by means of electron paramagnetic resonance techniques. The field-scanned electron-nuclear double resonance method was used to separate the spectra. It was found that the ratio of the intensities of the 2 spectra remained the same after various quenching procedures. This suggested that their formation had almost the same relative probability. Hyperfine interactions with S and H revealed the involvement of one S atom and one H atom in each center. If H was replaced by D, a quadrupole interaction on the latter could be determined by means of D electron-nuclear double resonance. 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 with a single H atom: (S-H)0 pairs.

I.S.Zevenbergen, T.Gregorkiewicz, C.A.J.Ammerlaan: Materials Science Forum, 1995, 196-201, 855-60