Solid state synthesis of LiBaBO_3:Ce~(3+)/Mn~(2+) phosphors and tunable luminescence induced by energy transfer from Ce~(3+) to Mn~(2+)

摘要

A series of Ce~(3+) and/or Mn~(2+) doped LiBaBO_3 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 LiBaBO_3, suggesting that the Ce~(3+) and Mn~(2+) ions have doped into LiBaBO_3 lattice and formed the solid solution. There is an obvious spectra-overlap between the emission spectrum of LiBaBO_3:Ce~(3+) and the excitation spectrum of LiBaBO_3:Mn~(2+), which suggests the possible occurrence of energy transfer from Ce~(3+) to Mn~(2+) in LiBaBO_3 host. The luminescent properties of LiBaBO_3:Ce~(3+)/7Mn~(2+) confirm the energy transfer from Ce~(3+) to Mn~(2+) in LiBaBO_3 host. Under the excitation at 345 nm, the emission spectra of LiBaBO_3:Ce~(3+)/Mn~(2+) consist of emission bands resulting from Ce~(3+) and Mn~(2+). When the Ce~(3+) concentration is fixed at 5 mol%, the emission intensity of Ce~(3+) decreases gradually with the increasing Mn~(2+) concentration, which is due to the higher and higher energy transfer efficiency from Ce~(3+) to Mn~(2+). As a result, the tunable luminescence of LiBaBO_3:Ce~(3+)/Mn~(2+) can be obtained by changing the codoped Mn~(2+) concentration.