Luminescence properties of Eu3+ doped CdF2 single crystals

Abstract This paper reports the photoluminescence properties of Eu3+ doped CdF2 single crystals. The pulled crystals were prepared by use of the Bridgman technique from a vacuum furnace in fluoride atmosphere. Absorption, excitation and emission spectra of the crystal doped with three Eu3+ concentrations (0.02%, 0.1% and 0.6% mol.) were recorded at room temperature. The emission spectra exhibit a strong yellow and red emissions in the spectral range 550–720 nm which are assigned to 5D0 → 7FJ (J = 1, 2, 4) transitions and a weak infrared emission around 816 nm corresponding to 5D0 → 7F6 transition. The magnetic dipole emission (5D0 → 7F1) is the most intense for each Eu3+ concentration. The Judd-Ofelt intensity parameters Ω2, Ω4, Ω6 for 4f-4f transitions of Eu3+ ions were computed from the emission spectra using the 5D0 → 7FJ (J = 1, 2, 4, 6) transitions. Via these phenomenological intensity parameters, the spontaneous emission probabilities, branching ratios, radiative lifetimes, quantum efficiencies and emission cross-sections for the main Eu3+ emitting levels are evaluated.