The migration of H in un-doped amorphous hydrogenated material was measured by using the elastic-recoil detection of variations in the dispersion parameter at temperatures of between 350 and 470C (table 54). It was found that the dispersion parameter increased with increasing annealing temperature.

Annealing-Temperature Influence on the Dispersive Diffusion of Hydrogen in Undoped a-Si:H. X.M.Tang, J.Weber, Y.Baer, F.Finger: Physical Review B, 1990, 42[11], 7277-9