Abstract
Phosphorus-doped and boron-doped hydrogenated amorphous silicon were studied by photoinduced absorption (PA) in the time range from 2 to 1800 ps. Prolonged light exposure (ℏω=2.0 eV) causes PA to decay more rapidly. The data are fit to a multiple trapping model. Minority carriers get trapped at deep defect states whose density increases with light exposure. These results are consistent with the interpretation that the light-induced defects in amorphous silicon are dangling bonds.