Eu2+ doped Ba2Sc2B4O11 phosphor for UV-violet-excited white LEDs

To achieve healthy illumination, phosphor-converted white light-emitting diodes (WLEDs) that can be excited by ultraviolet (UV)-violet light are becoming increasingly important. Herein, we report a novel yellow-emitting phosphor, Ba_2-xSc₂B₄O₁₁:xEu²⁺ (BSBO:Eu²⁺), which exhibits exceptional optical properties and is suitable for UV-violet-excited WLEDs. BSBO:Eu²⁺ shows a broad excitation spectrum ranging from 230 to 450 nm, and emits a yellow light with an ultrawide FWHM of about 137 nm centered at 577 nm. The internal and external quantum efficiencies of the phosphor were measured to be 89 % and 41 %, respectively. The fluorescence lifetime of BSBO:0.01Eu²⁺ was determined to be 2.74 μs. By combining BSBO:0.01Eu²⁺ with a commercial blue phosphor (BaMgAl₁₀O₁₇:Eu²⁺) and a 365 nm LED, we achieved a warm WLED with a correlated color temperature (CCT) of 4543 K. By further integrating a green phosphor ((Ba, Sr)₂SiO₄:Eu²⁺), the WLED achieved superior color quality, reaching an Ra of 93.0, in comparison with the commercial YAG:Ce³⁺ with an Ra of 78.4, and a CCT of 7078 K—well-suited for precise color reproduction needs.