Defect dynamics and the Staebler-Wronski effect in hydrogenated amorphous silicon

It is shown that four fundamental reactions involving floating bonds, dangling bonds, and H govern defect dynamics in $a$-Si: H under equilibrium and various nonequilibrium conditions. The Staebler-Wronski effect is a natural consequence of these reactions in the presence of excess electrons and holes. It is predicted that, under illumination or particle irradiation, both floating and dangling bonds can be created. Experimental data support this prediction and provide characteristic signatures for both defects. Though H may not be involved in the creation of the metastable defects, it plays a key role in their annealing.