Abstract
This paper demonstrates that recent measurements of the picosecond decay of photoinduced absorption (PA) in hydrogenated amorphous silicon can be explained by dispersive bimolecular recombination of band-tail electrons with holes trapped in the valence band and/or midgap states. The results explain the dependence of the decay on temperature and intensity and provide a framework for analysing PA decays over a range of intensities and trap densities.