A novel borate phosphor LuBaBO:Ce codoped with Sr/Tb 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 LuBaBO:Ce (0.1% ≤ ≤ 3.0%) and LuBaSrBO:0.5%Ce (0% ≤ ≤ 20%), and green-emitting phosphors LuBaBO: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.