Tunable white-light emission of Dy3+ or/and Eu3+ co-doped single-phase LiY(PO3)4 phosphors for NUV-WLEDs

• Published in: Journal of alloys and compounds 2019-06, Vol.791, p.833-838
• Main Authors: Wang, Zhong-Yue, Shen, Bing-Lei, Yu, Ke-Han, Yang, Zhen, Zheng, Rui-Lin, Hu, Er-Tao, Zheng, Jia-Jin, Wei, Wei
• Format: Article
• Language: English
• Subjects: CCT; Chromaticity; Energy transfer; Europium; Light emission; LiY1-m-nDymEun(PO3)4; Phosphors; Single matrix phosphors; Sol-gel processes; Tunable light emission; White light
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.03.406

A series of Dy3+ and Dy3+/Eu3+ co-doped LiY(PO3)4 phosphors are prepared by sol-gel combustion method, followed by annealing treatment at 700 °C for 10  min. XRD patterns and TEM images show that the LiY1-m-nDymEun(PO3)4 phosphors are characterized by monoclinic phase and regular short rod or nearly spherical granules. Excited at 363 nm, the Dy3+ single doped LiY(PO3)4 phosphors have two intense emission peaks at 482 nm and 574 nm. Its chromaticity coordinate point is centred at (0.305 ± 0.003, 0.33 ± 0.015) and its CCT is higher than 6700 K. By introducing Eu3+ ions to LiY0.96Dy0.04(PO3)4 phosphors, chromaticity coordinate point and CCT of LiY0.96-nDy0.04Eun(PO3)4 phosphors can be adjusted almost linearly due to energy transfer between Dy3+ ions and Eu3+ ions. The corresponding CCT of 4927–6052 K and chromaticity coordinate point of (0.3334 ± 0.0136, 0.3492 ± 0.0014) can be achieved for LiY0.96-nDy0.04Eun(PO3)4 (n = 0.03–0.05) phosphors with high luminescence thermal stabilities and energy transfer efficiency of more than 18.99%. These results indicate that Dy3+/Eu3+ co-doped LiY(PO3)4 phosphors are expected to be a promising single matrix white emitting phosphors with tunable white-light emission for NUV-WLEDs. [Display omitted] •LiY(PO3)4:Dy/Eu phosphor can be prepared by sol-gel combustion method.•LiY(PO3)4:Dy/Eu phosphors show a tunable white-light emission.•LiY0.96-nDy0.04 Eun(PO3)4(n > 0.03) has high ET efficiency (>19%).•LiY(PO3)4:Dy/Eu phosphor has high PL thermal stabilities (83% at 180 °C).•LiY0.92Dy0.04Eu0.04(PO3)4 show a CCT of 5398 K and coordinate (0.335, 0.35).