The covalently attached organic monolayer has great effects on the structures of the organic semiconductor thin films and their electronic transport properties in the fabrication of molecular electronic devices. A laser-induced dry-fabrication method has been developed to form bibenzyl-like molecular layers by photoinduced reaction of 4-bromostyrene molecules on silicon surface in the vacuum environment. The radical site produced via the C-Br bond cleavage concurrently reacts with the C=C vinyl group of the physisorbed 4-bromostyrene molecule above to form the -CH2-CHBr- covalent linkage. X-ray photoelectron spectroscopy (XPS) and high-resolution electron energy loss spectroscopy (HREELS) experimental results and density functional theory (DFT) calculations confirm the formation of covalently bonded bibenzyl-like (Phi-CH2-CHBr-Phi) molecular layers on the silicon surface. (C) 2014 Elsevier B.V. All rights reserved.