Dispersive diffusion of hydrogen in a-Si:H: Influence of the film deposition temperature

We have measured by the method of elastic-recoil detection analysis the dispersion parameter α of hydrogen diffusion in undoped a-Si:H. We find that a lowering of the deposition temperature of the films increases the value of α. This variation can also be clearly correlated with the increase of the initial concentration of weakly bound hydrogen, which is expected to reflect the disorder of the microstructure. These results will certainly contribute to the elucidation of the dispersive character of the diffusion of hydrogen in the different types of amorphous silicon.