It was concluded that the band tail density of states in amorphous hydrogenated material could be varied independently of the density of mid-gap defects. Also, the metastable mid-gap defect densities were not related to the valence band tail densities of states. It was suggested that these facts would be a convenient means for choosing between alternative models for the cause of metastability in amorphous hydrogenated material.

G.Ganguly, I.Sakata, H.Okushi, A.Matsuda: Japanese Journal of Applied Physics, 1995, 34[II-3A], L277-80