Eu:CaF2 layers have been grown epitaxially on Si using molecular beam epitaxy (MBE) with the intent of realizing an electrically pumped optical source on Si. Here we present an atomic force microscopy study of the morphological features of MBE-grown Eu:CaF2 on p-type Si(100) substrates and a study of electroluminescence (EL) from EL devices fabricated from these layers. The surface morphologies of the MBE-grown layers show an increased density of faceted features with increase in epilayer Eu content. X-ray photoelectron spectroscopy (XPS) data reveal the emergence of satellite peaks around the regular Eu XPS peaks in Eu:CaF2 layer with high Eu content. The characteristics of EL devices fabricated on these layers is presented and a possible EL mechanism is discussed.© 1998 American Vacuum Society.