工业铝酸钠溶液制备长余辉发光材料的基质组成及发光性能研究

Study on Matrix Composition and Luminescent Properties of Long Afterglow Luminescent Materials Prepared with Industrial Sodium Aluminate Solution

以工业铝酸钠溶液制备的氢氧化铝为原料,采用高温固相反应法,分别制备了蓝绿色、黄绿色和桔红色三种长余辉发光材料,并采用X射线衍射仪测定样品的物相,荧光分光光度计测定样品的激发光谱和发射光谱。结果表明:前驱体反应物中Sr/Al摩尔比的改变使样品的晶体结构发生改变,从而影响其发光性能;当Sr/Al摩尔比分别为2/7、1/2、3/2时,合成样品依次为纯相Sr4Al14O25∶Eu2+,Dy3+、SrAl2O4∶Eu2+,Dy3+、Sr3Al2O6∶Eu2+,Dy3+,余辉颜色分别为蓝绿色、黄绿色和桔红色;制备的三种长余辉发光材料的激发光谱和发射光谱均属宽带光谱,日光灯、太阳光等自然光均可有效激发这三种材料;随着Sr/Al摩尔比的增大,最强激发峰由350nm红移到450nm,最强发射峰由460nm红移到600nm。

The three kinds of bluish-green,yellowish-green and orange-red long afterglow luminescent materials were prepared by high-temprature solid-state synthesis with aluminum hydroxide prepared from industrial sodium aluminate solution as the raw material.The phase composition of the obtained samples was determined by X-ray diffractometer.The excitation and emission spectra of the samples were determined by fluorescence spectrophotometer.The determined results show that the alteration of Sr/Al molar ratio in precursor reactants causes the crystal structure of the samples to change and thus affect their luminescent properties.When Sr/Al molar ratio is 2/7,1/2 and 3/2,respectively,the synthesized samples are pure Sr4 Al14 O25∶Eu2＋,Dy^3＋,SrAl2 O4∶Eu2＋,Dy^3＋and Sr3 Al2 O6∶Eu2＋,Dy^3＋in turn,and they have bluishgreen,yellowish-green and orange-red afterglow color,respectively.All the excitation and emission spectra of the three prepared samples are broadband spectra,and they can be effectively excitated by the natural light such as sunlight and daylight lamps.With the increase of Sr/Al molar ratio,the strongest excitation peak is redshifted from 350 nm to 450 nm,and the strongest emission peak is also redshifted from 460 nm to 600 nm.