Si/beta-FeSi2/Si (SFS) heterostructures were grown epitaxially on Si(001) by reactive deposition epitaxy (RDE) for beta-FeSi2 and by molecular beam epitaxy (MBE) for Si. Distinct 1.54-mu m photoluminescence was observed at 77 K for SFS with a beta-FeSi2 thickness ranging from 5 to 10 mm. When the thickness of the beta-FeSi2 layer was increased up to 40 nm, the PL intensity of beta-FeSi2 decreased and the full-width at half maximum (FWHM) of the PL peak increased. Reflection high-energy electron diffraction observation revealed that the Si overlayer has a tendency to form polycrystalline structures with the increase of beta-FeSi2 thickness. The degradation of PL was also observed for samples annealed at 900 degrees C. (c) 2005 Elsevier B.V. All rights reserved.