Solid state synthesis of LiBaBO3:Ce3+/Mn2+ phosphors and tunable luminescence induced by energy transfer from Ce3+ to Mn2+

A series of Ce3+ and/or Mn2+ doped LiBaBO3 phosphors were synthesized by a conventional solid state reaction. The phase purity and luminescent properties of the obtained phosphors were investigated. The XRD patterns show that all of the obtained phosphors have the single phase similar to pure LiBaBO3, suggesting that the Ce3+ and Mn2+ ions have doped into LiBaBO3 lattice and formed the solid solution. There is an obvious spectra-overlap between the emission spectrum of LiBaBO3:Ce3+ and the excitation spectrum of LiBaBO3:Mn2+, which suggests the possible occurrence of energy transfer from Ce3+ to Mn2+ in LiBaBO3 host. The luminescent properties of LiBaBO3:Ce3+/Mn2+ confirm the energy transfer from Ce3+ to Mn2+ in LiBaBO3 host. Under the excitation at 345 nm, the emission spectra of LiBaBO3:Ce3+/Mn2+ consist of emission bands resulting from Ce3+ and Mn2+. When the Ce3+ concentration is fixed at 5 mol%, the emission intensity of Ce3+ decreases gradually with the increasing Mn2+ concentration, which is due to the higher and higher energy transfer efficiency from Ce3+ to Mn2+. As a result, the tunable luminescence of LiBaBO3:Ce3+/Mn2+ can be obtained by changing the codoped Mn2+ concentration.