Luminescence and energy transfer of Eu2+/Tb3+/Eu3+ in LiBaBO3 phosphors with tunable-color emission

A series of LiBaBO3:RE (RE = Eu2+/Tb3+/Eu3+) phosphors have been synthesized using the high-temperature solid-state reaction method. The X-ray diffraction (XRD), emission spectra, excitation spectra, decay lifetimes, and diffuse reflection spectra were utilized to characterize the phosphors. The as-prepared samples have been characterized via XRD measurement and showed that Eu2+/Tb3+/Eu3+ can be efficiently doped into the host. The obtained phosphors can emit different colors of light when doping with different activators. The energy transfer from Tb3+ to Eu3+ occurs in LiBaBO3:0.03Eu(3+), yTb(3+) prepared in the air. While an abnormal reduction phenomenon was reported when Eu and Tb ions were co-doped in LiBaBO3 and prepared in an inferior reductive atmosphere, which showed tunable-color from blue to red based on energy transfer of Eu2+ -> Tb3+ -> Eu3+ ions. And the energy transfer not only can occur between Eu2+ and Tb3+ ions, but also between Tb3+ and Eu3+ ions. All these results reveal that Tb3+ can play the role of storing the energy for Eu3+, and LiBaBO3 may be a potential candidate phosphor for LEDs.