Effect of deposition parameters on the properties of hydrogenated amorphous silicon films prepared by photochemical vapour deposition

Abstract

Hydrogenated amorphous silicon (a-Si:H) films were prepared by the process of mercury-sensitized photochemical vapour deposition. Substrate temperature, hydrogen dilution and chamber pressure were varied to optimize the rate of deposition and optoelectronic properties of these films. The properties as well as the growth rate depend sensitively on the substrate temperature. At optimum deposition conditions an a-Si:H film has been obtained with dark conductivity and photoconductivity ∼10 −10 S cm −1 and ∼10 −4 S cm −1, respectively, along with an optical band gap of 1.75 eV. The properties of the film are comparable to those obtained for films prepared by the glow discharge deposition technique.