Direct observations were made of light-enhanced H migration, in hydrogenated amorphous material, by means of secondary ion mass spectrometry. It was found that the enhancement of diffusion increased with the intensity of illumination in undoped material, and was suppressed in doped and compensated material. The enhancement was attributed to an increased release rate of H from Si-H bonds in the presence of photo-generated carriers.

P.V.Santos, N.M.Johnson, R.A.Street: Physical Review Letters, 1991, 67[19], 2686-9