Shallow thermal donors were generated in Czochralski-type material that was annealed at 470C in a H plasma. They were detected by using infra-red electronic absorption techniques, and had ground states which shifted slightly (about 0.1/cm) to smaller binding energies when D was introduced instead of H. This demonstrated the presence of a H atom in the donor core. No other infra-red spectrum was detected, apart from that which arose from neutral double thermal donors. The same optical transitions were observed in annealed samples that had been pre-heated in water vapor. The latter data revealed an NL10 electron paramagnetic resonance spectrum which had been attributed to H-passivated thermal donors. The relative intensities of the electron paramagnetic resonance NL10 spectra could be correlated with those of the shallow thermal donor infra-red spectra. This strongly suggested that both spectra arose from the same defects.

R.C.Newman, J.H.Tucker, N.G.Semaltianos, E.C.Lightowlers, T.Gregorkiewicz, I.S.Zevenbergen, C.A.J.Ammerlaan: Physical Review B, 1996, 54[10], R6803-6