The use of deep-level transient spectroscopy revealed the presence of an electron trap, E3(0.15), and a hole trap, H1(0.33), both of which were related to H and C, in hydrogenated n-type and p-type crystals. The E3 trap annihilated at temperatures above 40C, with an activation energy of about 0.7eV and an attempt frequency of about 107/s. On the other hand, the H1 trap was stable up to 100C; above which it disappeared with an activation energy of about 1.7eV and an attempt frequency of about 1019/s. The annihilation of the E3 trap was slowed by applying a reverse bias to the Schottky junction. This fact, and the smallness of the pre-exponential factor, suggested that the E3 trap became unstable upon capturing an electron from the conduction band. However, the large pre-exponential factor of the H1 trap suggested that its dissociation involved a large entropy change for the atomic motion of H. It was suggested that the E3 and H1 traps arose from 2 different defects which had similar origins and structures.

Y.Kamiura, M.Tsutsue, M.Hayashi, Y.Yamashita, F.Hashimoto: Materials Science Forum, 1995, 196-201, 903-8