It was recalled that the effect of light-soaking on a-Si:H films was well known as the Staebler–Wronski effect, although its detailed mechanism was still unclear. The effect of light-soaking with ultra-violet and white light on intrinsic a-Si:H films was studied. It was shown that device-quality a-Si:H films contained a considerable amount of O. The light soaking of the films in air affected low and high-H a-Si films differently. It was shown that deep levels in the gap introduced by light soaking were related to the presence of O. The H present in the film influenced the effects of light soaking differently, as a function of its concentration.

Defects Induced in Amorphous Silicon Thin Films by Light Soaking. B.Pivac, I.Kovacevic, I.Zulim: Thin Solid Films, 2002, 403-404, 513-6