New Yellow-Emitting Whitlockite-type Structure Sr1.75Ca1.25(PO4)2:Eu2+ Phosphor for Near-UV Pumped White Light-Emitting Devices

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• 作者：Haipeng Ji ; Zhaohui Huang ; Zhiguo Xia ; Maxim S. Molokeev ; Victor V. Atuchin ; Minghao Fang ; Saifang Huang
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：May 19, 2014
• 年：2014
• 卷：53
• 期：10
• 页码：5129-5135
• 全文大小：550K
• 年卷期：v.53,no.10(May 19, 2014)
• ISSN：1520-510X

文摘

New compound discovery is of interest in the field of inorganic solid-state chemistry. In this work, a whitlockite-type structure Sr<sub>1.75sub>Ca<sub>1.25sub>(PO<sub>4sub>)<sub>2sub> newly found by composition design in the Sr<sub>3sub>(PO<sub>4sub>)<sub>2sub>鈥揅a<sub>3sub>(PO<sub>4sub>)<sub>2sub> join was reported. Crystal structure and luminescence properties of Sr<sub>1.75sub>Ca<sub>1.25sub>(PO<sub>4sub>)<sub>2sub>:Eu<sup>2+sup> were investigated, and the yellow-emitting phosphor was further employed in fabricating near-ultraviolet-pumped white light-emitting diodes (w-LEDs). The structure and crystallographic site occupancy of Eu<sup>2+sup> in the host were identified via X-ray powder diffraction refinement using Rietveld method. The Sr<sub>1.75sub>Ca<sub>1.25sub>(PO<sub>4sub>)<sub>2sub>:Eu<sup>2+sup> phosphors absorb in the UV鈥搗is spectral region of 250鈥?30 nm and exhibit an intense asymmetric broadband emission peaking at 518 nm under 位<sub>exsub> = 365 nm which is ascribed to the 5d鈥?f allowed transition of Eu<sup>2+sup>. The luminescence properties and mechanism are also investigated as a function of Eu<sup>2+sup> concentration. A white LED device which is obtained by combining a 370 nm UV chip with commercial blue phosphor and the present yellow phosphor has been fabricated and exhibit good application properties.