Photoluminescence (PL) measurement technique was found to be effective in revealing the unique characteristics of beta-FeSi2 film formation on Si substrates by means of ion beam sputter deposition (IBSD) method. A strong photo luminescence peak at around 0.8 eV was observed for FeSi2 samples and also for Si substrates that were sputter etched by Ne+, and then thermally annealed in air at elevated temperature. Comparison with literature data indicated that the PL peak at 0.8 eV observed in this study was mainly from D I emission bands in Si substrate, whose intensity was enhanced by the sputter etching and the subsequent annealing of the substrate. Furthermore, comparison between CZ-Si and FZ-Si results indicated that the energy of 0.8 eV peak observed in this study was affected by the presence of oxygen in the Si bulk as well. (c) 2007 Elsevier B.V. All rights reserved.