High-efficiency cubic-phased blue-emitting Ba 3 Lu 2 B 6 O 15 :Ce 3+ phosphors for ultraviolet-excited white-light-emitting diodes.

In this work, Ce ³⁺ -activated Ba ₃ Lu ₂ B ₆ O ₁₅ (BLBO) blue-emitting phosphors were prepared, and their photoluminescence properties were studied. It was found that these phosphors can be excited over a broad excitation band range from 300 nm to 430 nm and generated a blue emission band in the 400-550 nm range with a maximum peak at 443 nm. The full width at half maximum of the blue emission band was about 68 nm. The optimal doping concentration of Ce ³⁺ ions was determined to be 3 mol. %, and the BLBO:0.03Ce ³⁺ phosphors possessed an internal quantum efficiency as high as 71%. Finally, by coating the phosphors with a blend of commercial CaAlSiN ₃ :Eu ²⁺ red-emitting phosphors, (Ba,Sr) ₂ SiO ₄ :Eu ²⁺ green-emitting phosphors, and BLBO:0.03Ce ³⁺ blue-emitting phosphors on a 380 nm ultraviolet light-emitting diode (LED) chip, a white LED device with a color-rendering index of ∼94 and correlated color temperature of 4952 K was obtained.