煅烧温度对红色长余辉发光材料Sr_3Al_2O_6:Eu^(2+),Dy^(3+)性能的影响

Effects of temperature on properties of red long afterglow phosphor Sr_3Al_2O_6:Eu^(2+),Dy^(3+)

采用溶胶凝胶法合成了Sr3Al2O6:Eu2+,Dy3+长余辉发光材料,利用X射线衍射仪(XRD)对材料的物相进行了分析,采用荧光分光光度计、照度计测定了样品的发光特性。XRD结果表明:随着煅烧温度的升高,SrCO3杂相的衍射峰越来越弱,Sr3Al2O6相的衍射峰越来越强,1200℃时发光基质为纯的Sr3Al2O6相,1250℃时出现新的SrAl2O4杂相。激发光谱和发射光谱结果表明:长余辉发光材料的激发峰位于473nm,发射峰位于612nm,归属于Eu2+的4f65d1→4f7特征发光。温度升至1250℃时,Eu2+的发射峰为612nm和520nm,后者归属于Eu2+在发光基质SrAl2O4中的发光。综合分析得制备Sr3Al2O6:Eu2+,Dy3+发光材料合适的煅烧温度为1200℃,在此温度下,材料具有较好的初始亮度和余辉时间。

The Sr3 Al2O6 ： Eu^2＋ , Dy^3＋ red - emitting phosphors were prepared by sol - gel method. The crystal structure were characterized by X -ray diffraction（XRD）. The excitation, emission and afterglow spectra were investigated by fluorescence spectrophotometer techniques. The results of XRD analysis show that Sr3 Al2O6 phase increases with the increase of calcined temperature, and the amount of SrCO3 crystalline phase decreases. The excitation peak of Sr2.95Al2O6：0.02Eu2＋ ,0.03Dy^3＋ phosphor is at 473 nm, and samples have the similar emission spectra with peak at 612 nm attributed 4f65d1→4f7 of divalent europium under 1200℃. There is a new emission peak at 520 nm at 1250℃, due to the divalent europium activated by SrAl2O4phosphor. The sample with optimized properties is prepared at 1200℃ on the basis of comprehensive analysis.