New results are reported on the effect of hydrogen dilution on the incorporation of hydrogen in undoped, unalloyed silicon films that were deposited by plasma-enhanced chemical vapor deposition in an rf-glow discharge system. A crystalline phase was detected for dilution ratios (H2: SiH 4) of 20:1 and greater. This phase change was accompanied by the appearance of higher-order silicon-hydride complexes. It was further observed that the H concentration in the films increased with dilution for ratios of 10:1 and greater. These results are compared with other recent studies of hydrogen dilution.