Luminescence of Eu3+ activated Ca3Ga2Ge3O12 garnet under UV-VIS and UV-VUV excitations

Abstract

Eu³⁺ activated Ca₃Ga₂Ge₃O₁₂ ceramics were prepared by solid-state reaction, and characterized with XRD, UV-VIS and UV-VUV spectroscopy at temperature range 10-300K. Structural analysis revealed only garnet phase. The results have shown that Eu³⁺ activated Ca₃Ga₂Ge₃O₁₂ exhibit efficient red emitting due to the ⁵D₀ → ⁷F_1,2,4 transitions under 393 nm (⁷F₀ → ⁵L₆ transition of Eu³⁺) or 250 nm (the broad O^2-→Eu³⁺ charge transfer band) excitations. A strong activator emission of Ca₃Ga₂Ge₃O₁₂:Eu³⁺ ceramics can also be obtained upon excitation with the synchrotron radiation in the long-wavelength fundamental absorption edge region and in the region of photon multiplication, where energy transfer from the host to the Eu³⁺ ions takes place.