Hydrogenated silicon thin films deposited by VHF PECVD process for various silane flow rates have been investigated. The silane flow rate was varied from 5 sccm to 30 sccm, maintaining all other parameters constant. The electrical, structural and optical properties of these films were systematically studied as a function of silane flow rate. These films were characterized by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy and UV-visible (UV-Vis) spectroscopy. Different crystalline volume fraction (22%-60%) and band gap (similar to 1.58 eV-similar to 1.96 eV) were achieved for silicon thin films by varying the silane concentration. A transition from amorphous to nanocrystalline silicon has been confirmed by Raman and FTIR analysis. The film grown at this transition region shows the high conductivity in the order of 10(-4) Omega(-1) cm(-1). (C) 2013 Elsevier B.V. All rights reserved.