Novel color-tunable K3Y(BO3)2:RE3+ (RE = Tb3+, Eu3+, Tb3+/Eu3+) phosphors for near-UV white LEDs

In this study, several borate phosphors K3Y(BO3)(2):RE3+ (RE = Tb3+, Eu3+, Tb3+/Eu3+) with adjustable luminescence color were synthesized by the traditional high-temperature solid-phase method. The crystal-phase composition, particle morphology, luminescence properties, and thermal stability of phosphors were studied by XRD, SEM, PL-PLE, FLT, DRS, and variable temperature fluorescence spectrum. Results show that no impurity is produced in the phosphors. The excitation spectra of single-doped K3Y1-x(BO3)(2):xTb(3+) and single-doped K3Y1-y(BO3)(2): yEu(3+) overlap at 484 nm. K3Y0.89(BO3)(2):0.11Tb(3+), yEu(3+) phosphors emit red and yellow-green light when excited at a wavelength of 377 nm. When Eu3+ concentration increases from 0.005 to 0.07, the emission intensity of Tb3+ decreases gradually, while that of Eu3+ increases gradually, which proves that Tb3+ -> Eu3+ energy transfer exists. The Tb3+ -> Eu3+ energy transfer efficiency reaches 53.54%, and energy transfer probability reaches 81.49%. At 377 nm, the co-doped phosphor color can range in the region of green, yellow, orange-red, and red. K3Y(BO3)(2):Tb3+/Eu3+ phosphor can be applied in the field of LEDs excited by near-ultraviolet light.