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 K₃Y_1-x(BO₃)₂:xTb³⁺ and single-doped K₃Y_1-y(BO₃)₂: yEu³⁺ overlap at 484 nm. K₃Y_0.89(BO₃)₂:0.11Tb³⁺, yEu³⁺ 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.