新型橙红色荧光粉Ca_9Al(PO_4)_7:Sm^(3+)的发光特性

Luminescent properties of a novel orange-red emitting phosphor Ca_9Al(PO_4)_7:Sm^(3+)

采用固相法合成了Ca9Al(PO4)7:Sm3+橙红色荧光粉,研究了材料的发光性质。结果表明,以403nm近紫外光作为激发源时,Ca9Al(PO4)7:Sm3+呈现出多峰特征,主峰位于564、605、650和712nm,分别对应Sm3+的4G5/2→6H5/2、4G5/2→6H7/2、4G5/2→6H9/2和4G5/2→6H11/2跃迁发射,其中605nm发射峰最强,从而材料整体发射橙红光;监测605nm发射峰,对应的激发光谱为多峰特征,主峰为345、362、375、403、440和472nm;改变Sm3+的掺杂量发现,Ca9Al(PO4)7:Sm3+的发射强度表现出先增大、后减小的变化趋势,发射强度最大值对应的Sm3+掺杂量为x=0.01,即存在浓度猝灭现象;通过计算临界距离,得出造成浓度猝灭的机理为电多极相互作用;测量了不同Sm3+掺杂量下材料的色坐标发现,Ca9Al(PO4)7:Sm3+的色坐标基本不变,位于橙红色区域。研究了Ca9Al(PO4)7:Sm3+的发射强度随温度的变化情况发现,材料具有较好的温度特性,激活能为0.178eV。

An orange-red emitting phosphor Ca9Al（PO4）7：Sm3＋was synthesized by a high temperature solid-state method,and its luminescent properties are investigated.Phase formation was determined by X-ray diffraction（XRD）in a Bruker AXS D8 advanced automatic diffractometer（Bruker Co.,German）with Ni-filtered Cu Kα1radiation（λ=1.5406nm）.Steady time resolved luminescence spectra,and excitation and emission spectra were detected by a fluorescence spectrophotometer（Hitachi F-4600）.Commission International de I′Eclairage（CIE）chromaticity coordinates of samples were measured by a PMS-80 spectra analysis system.Under 403 nm radiation excitation,Ca9Al（PO4）7：Sm3＋has several emission peaks,and they locate at 564 nm,605nm,650 nm and 712 nm,which are ascribed to 4G5/2→6H5/2,4G5/2→6H7/2,4G5/2→6H9/2and 4G5/2→6H11/2transitions of Sm3＋.And the strongest emission is 605 nm,so Ca9Al（PO4）7：Sm3＋presents orange-red light.The emission intensities of Ca9Al（PO4）7：Sm3＋are influenced by Sm3＋concentration,and can achieve the maximum at 0.01Sm3＋,and the concentration quenching effect of Sm3＋in Ca9Al（PO4）7：Sm3＋is observed.The mechanism of concentration quenching is thed-d interaction.CIE color coordinates of Ca9Al（PO4）7：Sm3＋locate in the orange-red region,and are not influenced by Sm3＋concentration.Under different temperatures,the emission intensities of Ca9Al（PO4）7：0.01Sm3＋are investigated,and the corresponding activation energy is calculated to be 0.178 eV,which prove the thermal stability of Ca9Al（PO4）7：Sm3＋.