The diffusion of H in P- and B-doped polycrystalline and microcrystalline Si was investigated by performing D-diffusion experiments. The D concentration profiles were measured as a function of temperature and concentration. The effective diffusion coefficient was thermally activated and varied from 0.01 to 1.69eV, in response to changes in the D and dopant concentrations. This variation was accompanied by a change in the diffusion pre-factor by more than 15 orders of magnitude (figure 5), and was consistent with reported results on H diffusion in hydrogenated amorphous Si. Using the theoretical diffusion pre-factor, the energy (EA) required to yield the diffusion coefficient was calculated. The EA value exhibited a Fermi-energy dependence which was similar to that of the formation energy of H+ and H- in c-Si. Based upon the experimental data, a unified microscopic model for H diffusion was proposed.

Hydrogen Migration in Doped and Undoped Polycrystalline and Microcrystalline Silicon. N.H.Nickel, I.E.Beckers: Physical Review B, 2002, 66[7], 075211 (13pp)