In order to contribute to the understanding of the optoelectronics properties of hydrogenated nanocrystalline silicon films, a detailed study has been conducted. Structural analysis (infrared absorption and Raman scattering spectroscopy), combined with optical measurements spectroscopy (optical transmission, photothermal deflection spectroscopy and photoconductivity) were used to characterize the films. The samples were elaborated by radio-frequency magnetron sputtering of crystalline silicon target, under a hydrogen (70%) and Argon (30%) gas mixture, at three different total pressures (2, 3 and 4Pa) and varying substrate temperature (100, 150 and 200°C). The results clearly indicate that the films deposited at 2Pa are amorphous, while for 3 and 4Pa nanocrystalline structures are observed. These results are discussed in the framework of the existing models.