Electron paramagnetic resonance measurements of float-zone material, which had been implanted with protons at 50K and heated to room temperature, revealed 2 signals which both originated from defects with spin S = ½ and monoclinic symmetry. The near-trigonal g tensors, and several sets of 29Si hyperfine splittings, all closely resembled those which had previously been observed for VH0; the neutral charge state of a monovacancy which was bound to a single H atom. Analysis of the minute proton hyperfine splitting of one of the above signals provided strong evidence that this signal originated from V2H0, the neutral charge state of a divacancy which was bound to one H atom. Parallel studies of the thermal decay of VH0, of the above signals, and of the infrared-absorption lines that were associated with Si-H stretching modes, indicated that VH0 possessed a stretching mode at 2038.5/cm, whereas modes at 2068.1 and 2073.2/cm originated from the defects with spin S = ½ and monoclinic symmetry. It was argued that the 2068.1/cm mode arose from V2H0, whereas the 2073.2/cm mode probably belonged to VnH0, where n was 3 or 4.

Electron paramagnetic resonance study of hydrogen-vacancy defects in crystalline silicon P.Stallinga, P.Johannesen, S.Herstrøm, K.B.Nielsen, B.B.Nielsen, J.R.Byberg: Physical Review B, 1998, 58[7], 3842-52