Luminescence properties of a new greenish blue emitting phosphor Na<sub>5sub>Ca<sub>4sub>(PO<sub>4sub>)<sub>4sub>F:Eu<sup>2+sup>
- 作者：Haiyi Xiao ; Zhiguo Xia<sup> ; sup><sup>xiazg426@yahoo.com.cnsup> ; Libing Liao<sup> ; sup><sup>lbliao@cugb.edu.cnsup> ; Jun Zhou ; Jiaqing Zhuang
- 关键词：Optical properties ; Luminescence ; Halophosphate phosphors
- 刊名：Journal of Alloys and Compounds
- 出版年：2012
- 期刊代码：45_09258388
- 类别：ms
- 出版时间：5 September, 2012
- 卷：534
- 期：Complete
- 页码：97-100
- 文件大小：641 K
摘要
A novel greenish blue emitting phosphor, Na<sub>5sub>Ca<sub>4sub>(PO<sub>4sub>)<sub>4sub>F:Eu<sup>2+sup>, was synthesized by a conventional solid-state reaction, and its phase formation was confirmed by using the X-ray powder diffraction (XRD) technique. The photoluminescence (PL) results showed that the phosphor could be efficiently excited by ultraviolet (UV) light at wavelength of 250-410 nm, and it exhibited bright greenish blue emission under 365 nm UV light. The emission spectrum showed a single broad band centered at 500 nm, corresponding to the 4f<sup>6sup>5d<sup>1sup> 鈫?#xA0;4f<sup>7sup> transition of Eu<sup>2+sup>. Eu<sup>2+sup> concentration dependent PL properties in Na<sub>5sub>Ca<sub>4sub>(PO<sub>4sub>)<sub>4sub>F:xEu<sup>2+sup> indicated that there was a dipole-dipole interaction of Eu<sup>2+sup> ions. The critical energy-transfer distance was around 19.8 脜. Furthermore, this phosphor had good thermal stability and its thermal quenching activation energy was 0.45 eV. The measured quantum efficiency of Na<sub>5sub>Ca<sub>4sub>(PO<sub>4sub>)<sub>4sub>F:0.01Eu<sup>2+sup> phosphor under 365 nm excitation is 76%, which means that the present phosphor is promising in the white light emitting diodes (LEDs) phosphors.