It was demonstrated that H diffusion in hydrogenated amorphous material was trap-controlled. A 1.4eV barrier was measured for deep D emission to a transport level in D-doped amorphous material. It was shown that light-enhanced diffusion in this material was caused by the light-enhanced de-trapping of H, and not by heating of the sample. Estimates were obtained for the free-H diffusion coefficient (3 x 10-8cm2/s), the mean H displacement between deep trapping events (25nm), and for other parameters that affected the measured H diffusion coefficient in this material.

H.M.Branz, S.E.Asher, B.P.Nelson: Physical Review B, 1993, 47[12], 7061-6