The increase in the metastable defect density of a series of samples of amorphous hydrogenated material, that had been deposited by using the hot-wire technique and which contained various bonded H contents, was examined. The equilibration temperature was found to be independent of the H content within the film. This could not be explained in terms of a simple H glass model in which all of the H within the sample was required for defect equilibration. When certain samples were annealed to above their deposition temperatures, they exhibited a significantly increased metastable defect density as compared with their minimal as-grown values. This suggested that some type of model which involved H motion might still be applicable if it were assumed that only a fraction of the bonded H was required for defect equilibration. An experimentally observed correlation between the reduced excess defect density as measured after light-soaking, and the reduced excess defect density as measured after thermal quenching of some samples, indicated that the thermally-induced and light-induced metastable defects might have the same microscopic origin.

M.Vanecek, A.H.Mahan: Journal of Non-Crystalline Solids, 1995, 190[1-2], 163-8