SiO2包覆Gd2O3：Er^3＋,Yb^3＋纳米粉的制备、结构及发光性能

Synthesis,Structure and Spectrum Properties of Gd_2O_3:Er^(3+),Yb^(3+) Nanometer Powder Coated with SiO_2

用微乳液法合成出SiO2包覆的Yb3+,Er3+离子双掺杂的Gd2O3粉体,X射线衍射结果表明所制备粉体为立方Gd2O3结构。透射电镜照片显示其颗粒形状近似为球形,粒径为10～40nm;该粉体在波长为980nm的半导体激光器激发下发射出中心波长为562nm的绿色和660nm的红色上转换荧光,分别对应于Er3+离子的4S3/2/2H11/2→4I15/2跃迁和4F9/2→4I15/2跃迁。发光强度和激发功率关系的研究揭示其均为双光子过程,能量传递和激发态吸收是上转换发光的主要机制。由于其具有高效的上转换发光性能,而经过纳米复合后制成的纳米Gd2O3(核)/SiO2(壳),容易溶于水并易于和有机物结合,能与生物分子结合。

The Gd2O3 ： Er^3＋ , Yb^3＋ nanometer phosphors coated with SiO2 was synthesized by the microemulsion method. The X-ray diffraction result indicated that the prepared powder crystallized in a cubic structure. The TEM pictures demonstrated that the powders had the near spherical shape and the particle size was about 10 - 40 nm. The up-conversion luminescence spectra of the phosphors had two groups of emission, corresponding to the 4S3/2/2H11/2-4115/2 and 4 4 F9/2 → 115/2 transitions of Er^3＋ , respectively, when excited by 980 nm. The strongest peak in green range was 562 nm and that in red range was 660 nm. The research on luminescent intensity and the exciting power relations revealed that this up-conversion process was a double-photons process. The energy transfer and excited-state absorption were the main mechanism on the up-converting luminescence. Because nanometer Gd2O3 （ nucleus ）/SiO2 （ shell ） had highly effective performance on the up-converting luminescence and it was easy to dissolve in the water and to unite with organic matter and biological member.