Hydrogenated microcrystalline silicon-carbon thin films have been deposited by plasma enhanced chemical vapour deposition technique at the substrate temperatures of 250 degrees C and 400 degrees C varying the radio frequency (RF) power in the 10- 100 W range. The effects of substrate temperature and RF power on the structural, compositional, optical, and electrical properties have been investigated. The increase of substrate temperature or RF power leads to a decrease of crystallinity degree and an enhancement of carbon content. Optical absorption in the UV-visible region and electrical conductivity are affected in a different way by the RF power and substrate temperature variations. Silicon grain nucleation of films deposited at the temperature of 250 degrees C on commercial doped tin oxide substrate has been explored, for different RF power, by means of X-ray diffraction measurements. (c) 2006 Elsevier B.V All rights reserved.