Hot-wire chemical vapor deposition is a promising method to deposit polycrystalline silicon (poly-Si) at a high deposition rate while maintaining a good material quality. In this paper, the effects of the hydrogen dilution ratio and substrate temperature on the film properties were investigated. Microstructures of the poly-Si films with different deposition parameters have been characterized by Raman scattering, Fourier transform infrared spectroscopy, and transmission electron microscopy. An enhancement in crystallinity was found when the hydrogen dilution ratio and substrate temperature increased. The hydrogen content in the film also decreased when both the hydrogen dilution ratio and substrate temperature increased. Under optimum conditions, the poly-Si film with a grain size of similar to 0.8 mu m and an electron mobility of similar to 28 cm(2)/V s was obtained. These poly-Si thin films have high potential in future low-cost photovoltaic devices. (c) 2005 Elsevier B.V. All rights reserved.