热处理温度对SrAl_2O_4:Eu^(2+),Dy^(3+)光谱及陷阱浓度的影响

Effect of annealling temperature on spectra and trap concentration of SrAl_2O_4: Eu^(2+),Dy^(3+) luminescent material

采用高温固相法制备了Sr0.96Al2O4:Eu0.02,Dy0.02,B0.08长余辉发光材料。研究了两步退火工艺中第二次退火温度对其晶体结构、激发光谱、发光光谱、余辉衰减特性、拉曼光谱和热释光光谱的影响。结果表明,随着第二次退火温度的升高,Dy Sr˙陷阱中的电子浓度逐渐增加,发光动力学级次逐渐增大,这有利于提高长余辉特性;样品的拉曼光谱峰值随退火温度的变化与V O˙˙浓度随退火温度的变化一致,这一点验证了长余辉发光材料的电子陷阱模型的有效性。在余辉测试时间内,第二次退火为1400℃×6 h的样品具有最大的余辉亮度,这源于它具有最大的Dy Sr˙陷阱中的电子浓度以及适中的时间衰减常数。

The long afterglow luminescent materials Sr0.96A12 O4：Eu0 02, Dy0 0：, B0.02 were synthesized via solid-state reaction. The effects of the second annealling temperature on crystal structure, excitation spectra, emission spectra, decay curves, Raman spectra and thermoluminescence spectra of the long afterglow phosphors were discussed. The results show that the concentrations of electrons trapped in Dysr＂ increase with enhancing the second annealling temperature, which is advantageous to improve the long afterglow properties. As the second annealling temperature increasing, the variations of the Ramam spectura values are well coincident with the variations of the Vo concentrations, which demonstrates the validity of the model of electron trap for the long afterglow luminescent materials. The sample with the second annealling temperature of 1400 C for 6 h possesses the highest brightness within the testing period, which results from the largest concentration of electrons trapped in Dysr＂ and the proper decay time constant.