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

• Published in: Journal of rare earths Vol. 42; no. 8; pp. 1479 - 1488
• Main Authors: Zeng, Fan, Ru, Jingjing, Zhao, Bing, Guo, Feiyun, Chen, Jianzhong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2024
• Subjects: LED device; Phosphor; Rare earths; Tantalate; LED device; Tantalate; Rare earths; Phosphor
• ISSN: 1002-0721
• DOI: 10.1016/j.jre.2023.07.014

Two novel phosphors LiBa4(1‒x)Eu4xTa3O12 (H-LBTO:xEu3+) and Li0.25Ba1‒xEuxTa0.75O3 (C-LBTO:xEu3+) 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 5D0→7F1 and 5D0→7F2. The optimum concentration of Eu3+ ions is 9 mol% for C-LBTO:xEu3+ samples and the quenching interaction type is the nearest-neighbor ion interaction. The thermal stability of the C-LBTO:0.09Eu3+ sample was investigated in detail and the device application further suggests that C-LBTO:0.09Eu3+ can be used as a red phosphor for near-UV excited w-LEDs in lighting. LiBa4(1‒x)Eu4xTa3O12 (H-LBTO:xEu3+) and Li0.25Ba1‒xEuxTa0.75O3 (C-LBTO:xEu3+) phosphors were customized by driving crystal phase transitions via adjusting the sintering temperature and Eu3+ ion doping concentration. The optimal sample of C-LBTO:0.09Eu3+ emits bright red light at 395 nm excitation, exhibiting excellent thermal stability and holding potential application in w-LEDs. [Display omitted]