Light and annealing induced changes in Si–H bonds in undoped a-Si:H

Light and annealing induced changes in Si–H bonds in undoped a-Si:H have been investigated by a differential infrared spectroscopy method. The light-induced changes in Si–H bonds are not monotonic, quite different from the usual Staebler–Wronski effect in electronic properties, and involve more complicated physics. The magnitude of the light-induced changes in Si–H bonds is proportional to the hydrogen content in the film. There may exist more than one microscopic process which determine the light-induced changes in Si–H bonds. Almost the whole a-Si:H network is affected when a-Si:H is subjected to light-soaking or to annealing. The light-induced changes in Si–H bonds may be an independent light-induced phenomenon or an auxiliary process of the metastable SWE defect creation.