Hole conductivity through neighboring Si‐H bonds in hydrogenated silicon

The spatially‐resolved electronic states of a model representation of Si‐H bonds on vacancies in hydrogenated amorphous silicon (a‐Si:H) have been calculated using a Greens’s‐funciton technique. We find no gap states in the host Si bandgap. In the vicinity of the defect, states near the valence‐band edge and, to a lesser extent, near the conduction‐band edge are removed. We relate our results to a model of the Si‐H bond as a barrier to band edge carriers. Parameters are derived that pertain to localization due to randomly located hydrogenated defects.