Chemical vapor deposition of hydrogenated amorphous silicon

Hydrogenated amorphous silicon films are made by atmospheric pressure chemical vapor deposition from polysilanes between 430 and 480 °C. The films have hole diffusion lengths up to 0.4 μm, as measured by the surface photovoltage technique. Oxygen impurities are shown to reduce the diffusion length. Stainless-steel and crystalline silicon substrates give slightly different results, implying that contamination is introduced by the substrates.