纳米Gd_2O_3:Tb^(3+)的多元醇法制备及发光特性

Luminescent Properties of Gd_2O_3:Tb^(3+) Nanoparticle by Polyol Method

以DEG为溶剂,分别配置一定比例的GdCl_3, TbCl_3作为前驱液,利用多元醇法合成可用于生物探针的Gd_2O_3:Tb^(3+)纳米晶;将一定量的APTES和TEOS加入制备好的溶液中,使得纳米晶Gd_2O_3:Tb^(3+)的表面包裹聚硅氧烷层。本实验通过马尔文粒度仪、 X射线衍射仪(XRD)、场发射扫描电镜(SEM)、透射电镜(TEM)、荧光分光光度计等检测方法研究不同煅烧温度和不同Tb^(3+)掺杂浓度对纳米晶Gd_2O_3的粒径、物相结构、和发光性能的影响。将真空干燥过的纳米晶Gd_2O_3:Tb^(3+)置于马弗炉中分别以600, 800, 1000℃进行煅烧,得到的样品经XRD表征后发现:当煅烧温度为800℃时,得到立方相结构的纳米Gd_2O_3:Tb^(3+)。通过研究不同Tb^(3+)离子掺杂浓度下纳米晶Gd_2O_3:Tb^(3+)的荧光强度表明:当Tb^(3+)离子浓度为5.0%时,纳米晶Gd_2O_3:Tb^(3+)的发射强度最强,尤其是在主发射峰545 nm附近Tb^(3+)的~5D_4→~7F_5能级跃迁峰,其峰值强度比掺杂浓度为2.5%时提高了39%; Tb^(3+)掺杂浓度升高至7.5%时,样品发生了浓度猝灭导致光谱强度下降。

Tb3+-doped Gd2O3 nanoparticles used as biological probes were synthesized by polyol method using DEG as solvent and mixture of GdCl3 and TbCl3 as precursor;the polysioxane shell was encapsulated on the surface of the nanoparticle in a mixed solution of APTES and TEOS.The effects of different Tb3+doping concentration and calcination temperature on the size,structure and luminescence properties of Gd2O3:Tb3+were investigated by measurements of X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM)and fluorescence spectrometer.The vacuum-dried nanocrystalline Gd2O3:Tb3+was placed in a muffle furnace and calcined at 600,800 and 1000℃respectively,and the obtained samples were characterized by XRD.Then,the fluorescence intensity of Gd2O3:Tb3+nanocrystals was studied at different doping concentrations of Tb3+ions.The result showed that when the calcination temperature was 800℃,the cubic phase structure of nano-Gd2O3:Tb3+could be obtained;the emission intensity of Gd2O3:Tb3+nanocrystals was the strongest.When the concentration of Tb3+ions was 5.0%,the emission intensity of Gd2O3:Tb3+nanocrystals was the strongest,especially at the 5D4→7F5 transition level of Tb3+near the main emission peak at 545 nm,which was increased by 39%,higher than that of the doping concentration of 2.5%;when the Tb3+doping concentration increased to 7.5%,the concentration quenching of the sample led to a decrease of spectral intensity.