微波法合成红色长余辉发光材料Gd2O2S:Eu,Mg,Ti及其发光特性

用微波辐射法首次合成了Gd2O2S:Eu,Mg,Ti红色磷光化合物,用X射线粉末衍射(XRD)、扫描电镜(SEM)、荧光分光光度计等对合成产物进行了分析和表征.结果表明:材料的晶体结构为六方晶系,与Gd2O2S的相同.颗粒的形貌为类球形,分散性较好,尺寸在1～2 μm之间.Gd2O2S:Eu,Mg,Ti的激发光谱呈带状,激发光谱主峰位于360 nm,另外在400,422,472 nm等处也有激发峰存在;发射光谱为线状光谱,归属于Eu3 的5DJ(J=0,1,2)到7FJ(J=O,1,2,3,4)的跃迁.随着Eu浓度的增加,位于蓝绿区的586,557,541,513,498,471,468 nm处的发射峰逐渐减弱,而主峰位于627 nm处的红光发射明显增强.当Eu浓度为6 mol%时,红光发射最强.Mg,Ti共掺杂可显著改善其余辉性质.

Synthesis of the Red Long Afterglow Phosphor Gd2O2S:Eu,Mg,Ti by Microwave Radiation Method and Its Luminescent Properties

Gd2O2S: Eu, Mg, Ti, a novel red long afterglow phosphor, was synthesized in microwave field. The synthesized phosphors were investigated respectively by XRD, SEM and fluorescence spectrophotometer. The results show that Gd2O2S: Eu, Mg, Ti phosphors possess hexagonal crystal structure, which is similar to that of Gd2O2S. The particles of Gd2O2S: Eu, Mg, Ti phosphors are basically spherical in shape, with good dispersing. The mean particle size is 1-2 microm. The excitation spectrum is a broad band and the main peak is at 360 nm. Moreover, excitation peaks at 400, 422 and 472 nm were found in the excitation spectrum. The emission spectrum shows that Gd2O2S: Eu, Mg, Ti has narrow emission peaks. The emission peaks are ascribed to Eu3+ ions transition from 5 D(J) (J = 0, 1, 2) to 7F(J) (J = 0, 1, 2, 3, 4). With the increase in Eu3+ molar ratio, the emission peaks at 586, 557, 541, 513, 498, 471 and 468 nm in the blue and green region weaken gradually relative to the main emission peak at 627 nm. Therefore the red emitting at 627 nm becomes strong gradually. When the molar ratio is 6%, the red emitting becomes the strongest. The Ti and Mg co-doping can obviously improve its long-afterglow property.