We present an atomistic model of light-induced defects (the Staebler-Wronski effect). The model is based in part on our observations of molecular-dynamics simulations with an ab initio code and requires a change in the charge of a well-localized state in the gap, such as a dangling bond, to nucleate a defect. The defects are formed at weak-bond sites in the network following a rearrangement caused by the change of the charge of the localized state.

• Received 14 November 1991

DOI:https://doi.org/10.1103/PhysRevLett.68.1888