Light-induced defect creation under pulsed subbandgap illumination in hydrogenated amorphous silicon

We have observed that pulsed subbandgap illumination creates dangling bonds with a density of about 10(18) cm(-3) in high-quality hydrogenated amorphous silicon films. Such a light-induced creation of dangling bonds can be accounted for in terms of a model in which self-trapping of holes in weak Si-Si bonds adjacent to a Si-H bond plays an important role. The kinetics of thermal annealing of the light-induced dangling bonds have been examined, in which half of the defects are annealed out at temperatures above 180degreesC, but half of them remain.