Published online by Cambridge University Press: 15 February 2011
X-ray irradiation-induced structural changes in undoped a-Si:H have been investigated in detail by X-ray photoemission spectroscopy (XPS). The Si2s and the Si2p peaks were found to shift simultaneously to lower bonding energies, by the same amount, with X-ray irradiation. The shifts are near saturation, at about 0.1 eV, after one hour of irradiation at the intensity used; they can be reversed almost completely, seemingly with an activation energy lower than that for the metastable changes in electronic properties (Staebler-Wronski effect). The present results suggest that essentially the whole Si network structure is affected by the X-ray irradiation.