Abstract

In this work, evidence for matching blue chips with Ce:YAG single crystal phosphor is given. Forward current ( ${ I} _{\rm f}$ ) and red phosphor were investigated and discussed to improve the electroluminescent properties of WLEDs using Ce:YAG single-crystal phosphors. Optimum forward current of such a device is chosen at above 45 mA. The structure of ${Sr}_{2}{Si}_{5} {N} _{8}$ : ${Eu}^{2+}$ phosphor/Ce:YAG single crystal/blue chip enormously improved the color temperature and color rendering index. This method can be a solution to achieve warm white light. The chromaticity of this structure with the color temperature of 5629 K and color rendering index of 77.1 is $({\rm CIE~ x}, {\rm CIE~ y}) = (0.3296, 0.3369)$ closely meeting the demand for ideal white light for general lighting (0.33, 0.33), but the luminous efficiency ( $\eta_{\rm L}$ ) is lower at 81.04 lm/W in comparison to that of the Ce:YAG single crystal/blue chip structure at 94.55 $~$ lm/W.

© 2015 IEEE

White light emission from blue and near ultraviolet light-emitting diodes precoated with a Sr₃SiO₅:Ce³⁺,Li⁺ phosphor

Ho Seong Jang and Duk Young Jeon
Opt. Lett. 32(23) 3444-3446 (2007)

Design, synthesis and characterization of a new apatite phosphor Sr₄La₂Ca₄(PO₄)₆O₂:Ce³⁺ with long wavelength Ce³⁺ emission

Ge Zhu, Yurong Shi, Masayoshi Mikami, Yasuo Shimomura, and Yuhua Wang
Opt. Mater. Express 3(2) 229-236 (2013)

Novel yellowish-orange Sr₈Al₁₂O₂₄S₂:Eu²⁺ phosphor for application in blue light-emitting diode based white LED

Te-Wen Kuo, Chien-Hao Huang, and Teng-Ming Chen
Opt. Express 18(S2) A231-A236 (2010)

Thermally stable multi-color phosphor-in-glass bonded on flip-chip UV-LEDs for chromaticity-tunable WLEDs

Pengqiang Jiang, Yang Peng, Yun Mou, Hao Cheng, Mingxiang Chen, and Sheng Liu
Appl. Opt. 56(28) 7921-7926 (2017)

Flexible fabrication of a patterned red phosphor layer on a YAG:Ce³⁺ phosphor-in-glass for high-power WLEDs

Yang Peng, Yun Mou, Xing Guo, Xujia Xu, Hong Li, Mingxiang Chen, and Xiaobing Luo
Opt. Mater. Express 8(3) 605-614 (2018)