Complexes of H-O-vacancy type, in crystalline material, were studied by means of optical absorption measurements. The H atoms were introduced into Czochralski-type specimens by annealing at high temperatures in a H atmosphere. After irradiation to a dose of 1016/cm2, 3 new series of optical absorption lines at 180 to 350/cm developed successively, and annihilated at 250 to 600C during isochronal annealing. They were attributed to the electronic transitions of 3 forms of shallow donor, D1, D2 and D3, which contained H, O and a vacancy. The generation process of D1, which was the first to form, was investigated by isothermal annealing. The activation energy for D1 creation was estimated to be 1.68eV. On the basis of a study of the annealing behavior of radiation-induced defects, it was suggested that vacancy-O pairs probably played an important role in the D1 generation process.

H.Hatakeyama, M.Suezawa, V.P.Markevich, K.Sumino: Materials Science Forum, 1995, 196-201, 939-44