用微乳液法合成出SiO2包覆的Er3+掺杂的Y2O3粉体。X射线衍射结果表明, 所制备粉体为立方Y2O3结构。透射电镜照片显示, 其颗粒形状近似为球形, 粒径为20～50 nm。该粉体在波长为980 nm的半导体激光器激发下发射出中心波长为562 nm的绿色和660 nm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的关系揭示其均为双光子过程。Er3+掺杂的Y2O3粉体具有高效的上转换发光性能, 而经过纳米复合后制成的Y2O3(核)/SiO2(壳)在水溶液中具有较好的悬浮性, 这对于其在生物荧光标记的应用具有重要意义。

The Y2O3∶Er3+ nanometer phosphors coated with SiO2 was synthesized by the microemulsion method. The X-ray diffraction results showed that the as-prepared powders were cubic phase of Y2O3. The TEM pictures demonstrated that the powders have the nearly spherical and the average diameter of the particles was in the range of 60～80 nm. Under the excitation of 980 nm diode laser, a very strong green emission centered at 562 nm and a red emission centered at 660 nm were observed, which were assigned to the transitions of 4S3/2/2H11/2→4I15/2 and 4F9/2→4I15/2 energy levels of Er3+ ions, respectively. The research on luminescent intensity and the exciting power relations revealed that this up-conversion process was a two-photons absorption process. Because Y2O3 (nucleus)/SiO2 (shell) has highly effective performance on the up-conversion luminescence and was easy to dissolve in the water and united with organic matter and biological member, the application of this nanometer nuclear-shell structure material in the biological fluorescence mark domain is significance.