Development of a novel Eu3+-doped tantalate red-emitting phosphor for w-LEDs application

Two novel phosphors LiBa4(1-x)Eu4xTa3O12 (H-LBTO:xEu(3+)) and Li0.25Ba1-xEuxTa0.75O3 (C-LBTO:xEu(3+)) were prepared successfully by a molten salt method. The transformation between these two structures was realized by changing the sintering temperature or changing the Eu3+ ions concentration, which was also demonstrated by the X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectra (DRS), and photoluminescence excitation (PLE) analyses. Both the sintering temperature and the Eu3+ ions doping concentration have significant impact on the formation of the crystal phase. All these phosphors sintered at 1023 K exhibit two major luminescence lines at 594 and 614 nm under near-UV light of 395 nm excitation, corresponding to Eu3+ ions typical transitions of D-5(0)-> F-7(1) and D-5(0)-> F-7(2). The optimum concentration of Eu3+ ions is 9 mol% for C-LBTO:xEu(3+) samples and the quenching interaction type is the nearest-neighbor ion interaction. The thermal stability of the C-LBTO:0.09Eu(3+) sample was investigated in detail and the device application further suggests that C-LBTO:0.09Eu(3+) can be used as a red phosphor for near-UV excited w-LEDs in lighting. (c) 2023 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.