Tb~(3+)和Ce~(3+)在Sr_7Zr(PO_4)_6基质中能量传递及发光特性研究

用高温固相法制备了Sr_7Zr(PO_4)_6∶Tb~(3+)、Sr_7Zr(PO_4)_6∶Ce~(3+)及Sr_7Zr(PO_4)_6∶Tb~(3+),Ce~(3+)一系列荧光粉,并通过X射线衍射仪及荧光光谱仪分析了其结构和发光性质。结果表明,Sr_7Zr(PO_4)_6∶Tb~(3+)呈现特征绿色发射,最强发射峰位于543 nm,属于Tb~(3+)的5D4→7F5跃迁,激发峰位于226 nm处,但激发带较窄。为拓宽其激发带的宽度,在Sr_7Zr(PO_4)_6∶Tb~(3+)中掺入了Ce~(3+),观察到掺入Ce~(3+)后激发带变宽,且在Ce~(3+)的激发波长处激发得到了Tb~(3+)的发射,表明存在Ce~(3+)到Tb~(3+)的能量传递。

Luminescence Properties and Energy Transfer Between Ce3+ and Tb3+ in Sr7Zr(PO4)6

The phosphors of Sr7Zr(PO4)6∶Tb3+, Sr7Zr(PO4)6∶Ce3+ and Sr7Zr(PO4)6∶Tb3+,Ce3+ were prepared by the solid-state reaction.The structures of these powders were characterized by X ray diffractometer (XRD).The excitation and emission spectra were characterized by spectrofluorimeter.The excitation spectrum of Sr7Zr(PO4)6∶Tb3+ shows a narrower band in the range of 200-250 nm with the maximum centered at 226 nm, which belongs to 7FJ→7DJ transition of Tb3+.The photoluminescence spectra of Sr7Zr(PO4)6∶Tb3+ exhibits four emission peaks.The strongest green emission peak is at 543 nm which belongs to 5D4→7F5 transition of Tb3+.The excitation spectrum of Sr7Zr(PO4)6∶Ce3+ shows a broad band centered at 289 nm and the emission peak is at 374 nm.In order to broaden the width of the excitation band of Sr7Zr(PO4)6∶Tb3+,Ce3+ ions are incorporated.It is found that the excitation band became broader.The excitation spectrum of Sr7Zr(PO4)6∶Ce3+,Tb3+ shows two broad bands, respectively, the former belongs to the excitation of Tb3+ and the latter belongs to the excitation of Ce3+.The emission spectra of Sr7Zr(PO4)6∶Ce3+,Tb3+ exhibit strong emission peaks of Tb3+ excited by 289 nm, which is the excitation band center of Ce3+.It is speculated that the energy transfer occurs from Ce3+ to Tb3+.