Dy^(3+)掺杂对CaLaAl_3O_7晶体结构和发光性能的影响

Effect of Dy^(3+) Doping on Crystal Structure and Luminescent Properties of CaLaAl_3O_7

采用高温固相法制备了CaLa1-xAl3O7∶xDy3+(0≤x≤0.15)发光粉体,利用X射线衍射分析了材料的物相,计算发现:随Dy3+掺杂浓度的增加,晶胞体积线性减小。在348 nm光激发下,该系列样品发射谱为Dy3+的4f9组态内的特征发射峰,峰值波长分别为478 nm、577 nm和667 nm,总的发射呈现白色,色坐标计算值几乎相同,而且都处于白光区域内(色坐标(0.33,0.33))。CaLa1-xAl3O7∶xDy3+材料发光强度随Dy3+浓度的增大呈现先增大后减小的趋势,在x=0.04时达到峰值。分析了材料在577 nm发射强度与Dy掺杂浓度的关系,并根据D.L.Dexter的相关理论得到:Dy3+自身猝灭机理是电偶极-偶极相互作用。

Abstract：The Cal1-xAl3O7： xDy3＋ （0 x G0. 15 ） phosphors were synthesized by high temperature solid- state rmethod. The phase was characterized by X-ray diffraction （XRD）. The effects of Dy^3＋ doped concentration on crystal structure and luminescence properties of CaLa1-xAl3O7：xDy^3＋were studied. The unit cell volume decreases as Dy^3＋doped concentration ion increasing. The luminescence of CaLaAl3O7：Dy^3＋under 348 nm excitation originated from Dy^3＋ characteristic emission, the 478 nm, 577 nm and a small peak at 667 nm. The chromaticity coordinates of luminescence of CaLal-xAl3OT： xDy^3＋ have almost the same value, which are close to CIE isoenergetic white light point （x = 0. 33, y = 0. 33）. The effect of Dy^3＋ concentration on the emission intensity of CaLa1-xA13O7： xDy^3＋ was investigated. The result shows that the emissionintensity of CaLa1-x, A13O7 ： xDy^3＋ phosphor firstly increasesd as Dy^3＋ concentration increasing, then decreasesd, viz, the concentration quenching exists. The Dy^3＋concentration corresponding to the maximal emission intensity is 4 mol%. The concentration quenching mechanism is the d-d interaction by Dexter theory.