4.7 Article

Near-UV-excitable broadband green-emitting Ca2LaHf2GaAl2O12:Ce3+garnet-type phosphors for high color rendering warm-white LEDs

期刊

CERAMICS INTERNATIONAL
卷 49, 期 16, 页码 26420-26427

出版社

ELSEVIER SCI LTD
DOI: 10.1016/j.ceramint.2023.05.178

关键词

Solid-state lighting; Color rendering index; Quantum efficiency; Photoluminescence; Thermal quenching

向作者/读者索取更多资源

This paper reports on the preparation, crystal structure, and photoluminescence properties of a novel green-emitting garnet-type phosphor. It was found that the optimal doping concentration of Ce3+ ions is 6 mol%. The synthesized phosphor exhibits high thermal stability and high photoluminescence performance, making it promising for application in high color rendering white LEDs.
Efficient broadband green-emitting phosphors are promising for application in high color rendering white light-emitting diodes (LEDs). In this paper, we report on the preparation, crystal structure and photoluminescence properties of a novel green-emitting Ca2LaHf2GaAl2O12:Ce3+ (CLaHGA) garnet-type phosphor. All these CLaHGA:xCe3+ (x = 4, 6, 8, 10, and 12 mol%) phosphors have been synthesized through using the conventional high-temperature solid-state reaction method. It has been found that the optical property of phosphors critically depends on Ce3+ content, and the optimal doping concentration of Ce3+ ions is 6 mol%. The optimal CLaHGA:6% Ce3+ sample has a cubic structure with the space group Ia 3 d and lattice parameters of a = b = c = 12.62662 & ANGS; and V = 2013.08 & ANGS;3. The CLaHGA:xCe3+ phosphors exhibit an intense absorption band in the 300-485 nm range with a peak at 421 nm, due to the spin-allowed and parity-allowed 4f & RARR;5d transition of Ce3+ ions. Upon 421 nm excitation, CLaHGA:xCe3+ phosphors give rise to bright broad green emission bands in the 435-750 wavelength region with peak ranging from 519 to 531 nm, owing to the spin-allowed and parity-allowed 5d & RARR;4f transition of Ce3+ ions. For the optimal CLaHGA:6%Ce3+ sample, its CIE color coordinates and internal quantum efficiency are determined to be (0.3135, 0.4851) and 40.7%, respectively. The full width at half maximum of CLaHGA:6% Ce3+ is much larger than the commercial (Ba,Sr)2SiO4:Eu2+ green phosphor (124 nm versus 71 nm), while its emission intensity is only about 39% of that of (Ba,Sr)2SiO4:Eu2+. Besides, the thermal stability of CLaHGA:6% Ce3+ has also been studied. A white LED device is fabricated using the synthesized CLaHGA:6%Ce3+ green phosphors, showing a bright warm-white light emission with high color rendering index of Ra = 89.7 and low correlated color temperature of 4058 K.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.7
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据