Eu-doped CaF2 grown on Si(100) substrates by molecular beam epitaxy

Eu is incorporated into CaF2 films grown on Si(100) by molecular beam epitaxy using elemental Eu evaporation. Eu doping as high as 4.05 at. % does not significantly degrade the surface morphology, indicating a relatively high solubility of Eu in CaF2. Photoluminescence spectra from Eu‐doped CaF2 show strong blue emissions from Eu2+ ions in cubic sites. The inhomogeneous broadening of the zero‐phonon line near 24 190 cm−1 is reduced by ∼20% upon in situ annealing at 1100 °C.Peer reviewedPhysic