Tunable luminescence of blue-green emitting NaBaBO3:Ce3+,Tb3+ phosphors for near-UV light emitting diodes

A series of blue-green emitting NaBaBO3:Ce3+, Tb3+ phosphors were synthesized via conventional high temperature solid-state reaction method. The crystal structure, luminescence properties, energy transfer processes and the properties of the packing LED device were investigated. The phosphors present tunable luminescence in the blue-green region due to the energy transfer from Ce3+ to Tb3+. The internal quantum efficiency (IQE) and external quantum efficiency (EQE) of the composition optimized NaBaBO3:0.01Ce3+, 0.03 Tb3+ phosphor reached 57% and 36%, respectively. Using a 365 nm NUV LED chip combining with NaBaBO3: 0.01Ce3+, 0.03 Tb3+ phosphor and CaAlSiN3:Eu2+ red phosphor, a high quality white light was obtained with CIE chromaticity coordinates of (0.316, 0.307), CCT of 6473 K, and CRI of 81.4. These results demonstrated that NaBaBO3:Ce3+,Tb3+ phosphors is a promising blue-green phosphor for NUV white LEDs. •The energy transfer of Ce3+→Tb3+ in NaBaBO3 phosphors has been confirmed.•Quantum efficiency has been calculated.•The emission colors can be varied from blue to blue-greenish through controlling Tb3+ concentrations.•Potential candidates to be used as blue-green phosphor for NUV excited white LEDs.