This report describes the most significant results of the three phases: (1) development of a second harmonic detection technique for electron spin resonance (ESR) and optically excited ESR (LESR) in a-Si:H and related alloys, (2) discovery of universal kinetics for the decay of optically excited electrons and holes in a-Si:H and related alloys at low temperatures, (3) first detection of optically excited band-tail electrons and holes in hydrogenated amorphous germanium (a-Ge:H), (4) first ESR study of the kinetics for the production of silicon dangling bonds in a-Si:H at low temperatures, and (5) determination from 1H NMR that there exists an order of magnitude more molecular hydrogen (H2) in a-Si:H than previously measured.