Development of red phosphor Li8CaLa2Ta2O13:Eu3+ for WLEDs and anti-counterfeiting applications

• Published in: ChemPhysMater 2024-04, Vol.3 (2), p.194-203
• Main Authors: Ru, Jingjing, Zeng, Fan, Zhao, Bing, Ye, Chenqing, Zhong, Tonghui, Guo, Feiyun, Chen, Jianzhong
• Format: Article
• Language: English
• Subjects: LED device; Luminescence; Phosphor; Tantalate
• ISSN: 2772-5715; 2772-5715
• DOI: 10.1016/j.chphma.2023.11.002

A set of novel red phosphors Li8CaLa2Ta2O13:xEu3+ (LCLTO:xEu3+) were successfully prepared using a solid-state reaction method. The properties of the prepared samples, including phase purity, elemental composition, and morphology, were systematically investigated using X-ray diffraction, scanning electron microscopy, and diffuse reflectance spectroscopy analyses. The 610 nm maximum emission peak is attributed to the 5D0→7F2 transition of Eu3+ ion under 394 nm irradiation. Among all the LCLTO:xEu3+ phosphors, LCLTO:0.6Eu3+ showed the strongest emission intensity because of the concentration quenching effect of the electric dipole–dipole interaction among the Eu3+ ions, which was also demonstrated by the decay curves. Remarkably, the emission intensity of the optimal LCLTO:0.6Eu3+ phosphor, which exhibited a high internal quantum efficiency of 49.30% and excellent color purity of 96.79%, was approximately 2.29 times higher than that of commercial Y2O3:Eu3+ red phosphors. The thermal stability of the LCLTO:0.6Eu3+ sample with good color stability was meticulously investigated. The fabricated white-light-emitting diode (WLED) exhibited a superior color-rendering index of Ra = 82 and chromaticity coordinates of (0.3260, 0.3639), suggesting that LCLTO:0.6Eu3+ has potential applicability in developing efficient and high-quality WLEDs. Moreover, the prepared LCLTO:0.6Eu3+/PDMS composite film demonstrated exceptional flexural resistance and chemical stability, indicating considerable promise for practical anti-counterfeiting applications.