It was suggested that Fe was compensated by a donor that was related to the 2316/cm local vibrational mode, and which had previously been attributed to the fully hydrogenated In vacancy, VInH4. By using an  ab initio  local density functional code, it was found that VInH4 acted as a single shallow donor. It exhibited a triplet vibrational mode which was consistent with this assignment. The other hydrogenated vacancies, VInHn, where n was 1 or 3, were also analyzed and their structures, vibrational modes, and charge states were determined. Substitutional group-II impurities also acted as acceptors, but could be passivated by H. An investigation was made of the passivation of Be by H, and it was deduced that the H sat at a bond-centered site and was bonded to its P neighbor. The calculated vibrational modes were in good agreement with experiment.

C.P.Ewels, S.Oberg, R.Jones, B.Pajot, P.R.Briddon: Semiconductor Science and Technology, 1996, 11[4], 502-7