A novel borate phosphor Lu 5 Ba 6 B 9 O 27 :Ce 3+ codoped with Sr 2+ /Tb 3+ for NUV-white light emitting diode application

At present, there are still challenges in developing highly efficient and thermally stable phosphors for ultraviolet/near ultraviolet-white light emitting diodes (UV/NUV-WLEDs). Herein, we use traditional high-temperature solid-state reactions to prepare blue-emitting phosphors Lu Ba B O : Ce (0.1% ≤ ≤ 3.0%) and Lu Ba Sr B O :0.5%Ce (0% ≤ ≤ 20%), and green-emitting phosphors Lu Ba B O :0.5%Ce , Tb (0% ≤ ≤ 16%), abbreviated as LBB: Ce , LBB:0.5%Ce , Sr and LBB:0.5%Ce , Tb , respectively. Upon 340 nm excitation, LBB:Ce exhibits an asymmetric blue emission ranging from 360 nm to 480 nm. Furthermore, the emission intensity of LBB:0.5%Ce increased 4.8-fold without a spectral shift through the partial substitution of Sr for Ba . Through constructing the Ce → Tb energy transfer in the LBB structure, the temperature-dependent integral emission intensity at 483 K improved from only 25% to 68% of the intensity at 303 K due to the existence of fast energy transfer from Ce to Tb . The related results indicate that LBB: Ce , LBB:0.5%Ce , Sr and LBB:0.5%Ce , Tb phosphors can be used for UV/NUV-WLEDs.