It was recalled that studies of the H vibrations of H-containing complexes had often led to unexpected results. Some cases where the novel properties of impurity-H complexes had been revealed by their H vibrations were considered. In one case, a closer look at the spectrum of SiGaH-containing GaAs (for various Si isotopes), and also at the corresponding SiGa-D bands, had permitted an estimation to be made of the anharmonicity of the H-stretching vibrations. In another study, an examination of the isotopic splittings revealed values which were smaller than expected on the basis of the reduced mass of a Si-H oscillator. The size of the Si isotope shifts was explained in terms of a dynamic bond-strength variation, in which the force constant of the Si-H bond varied as the H atom vibrated. It was concluded that such studies illustrated the richness of the information that was provided by the H vibrational spectra, and that a close look at even apparently well understood H-containing defects often revealed new characteristics.

M.Stavola, J.F.Zheng, Y.M.Cheng, C.R.Abernathy, S.J.Pearton: Materials Science Forum, 1995, 196-201, 809-16