柠檬酸凝胶燃烧法制备GGG∶Eu^(3+),Bi^(3+)多晶发光粉体及其表征

Preparation and Characterization of GGG∶Eu^(3+),Bi^(3+) Polycrystalline Luminous Powders by Citric Acid Sol-gel Combustion Method

本文以Gd_2O_3、Ga_2O_3、Eu_2O_3、Bi(NO_3)_3·5H_2O和柠檬酸为原料,采用凝胶燃烧法制备出GGG∶Eu^(3+),Bi^(3+)多晶发光粉体,并对样品进行了XRD、SEM、FT-IR、PL测试。XRD和FT-IR分析结果表明合成的发光粉体均形成GGG相。SEM显示样品晶粒呈球形或类球形,直径约60 nm。PL分析显示样品最强发射峰位于592 nm处,属于Eu^(3+)的5D0-7F1磁偶极跃迁。掺杂Bi^(3+)的样品发光强度明显高于未掺杂Bi^(3+)的样品,而发射峰位置不变,当掺杂的Bi^(3+)浓度逐渐增加时,样品GGG∶Eu^(3+)0.05,Bi^(3+)x的发光强度先随Bi^(3+)浓度的增加而不断增强,当体系中掺杂Bi^(3+)的摩尔分数达到x=5%时,GGG∶Eu^(3+)0.05,Bi^(3+)x的发光强度达到最大值。再之后随Bi^(3+)掺杂浓度的增加发光强度减弱,这可能是因为Bi^(3+)和Eu^(3+)之间的能量传递方式主要是偶极-偶极作用,传递效率主要决定于两种离子间距离。

The GGG∶ Eu3＋,Bi3＋polycrystalline luminous powders were successfully synthesized by a solgel combustion strategy with Gd2O3,Ga2O3,Eu2O3,Bi（ NO3）3·5H2O and citric acid. The prepared materials were characterized by X-ray diffraction（ XRD）,Scanning electron microscope（ SEM）,Fourier transform infrared（ FT-IR）,and photoluminescence（ PL）. The XRD and FT-IR results showed that the structure of the powders was GGG phase. And the SEM image showed that the powders were nearly spherical or spherical grains with the diameter about 60 nm. The results of PL showed that the maximum fluorescence emission peak was 592 nm,which was corresponding to the5D0-7F1 of Eu3＋. Moreover,the luminescence intensity of the samples with Bi3＋was distinctly stronger than that of non-doped Bi3＋,and the emission peak position was not changed. The luminous intensity of the Eu3＋0. 05,Bi3＋xgradually enhanced with the increase of the percent of Bi3＋,and the intensity intended to maximum at x = 5%.However,the luminous intensity decreased with the further raise the amount of Bi3＋,which indicated that the energy transfer between Eu3＋and Bi3＋was dipole-dipole interaction,and the transfer effect was based on the distance of two ions.