Abstract
The dependence of the hydrogen diffusion coefficient on the material growth conditions in doped hydrogenated amorphous silicon has been measured, using secondary-ion mass spectrometry. A greatly enhanced diffusion was found in material with a columnar microstructure because of the preferential motion of hydrogen along the columns. Increasing the deposition temperature in non-columnar material results in a higher diffusion coefficient and a lower hydrogen concentration. No significant change in the diffusion was found with different n-type dopants.