中文摘要：

用水热法制备了PEI／CeF3：Tb3＋纳米晶体，运用透射电子显微镜，X射线衍射，傅立叶变换近红外光谱，对样品进行了表征。结果表明：所得纳米晶体平均粒径为10nm，呈比较规则的立方体形；纳米晶体表面包覆有PEI，因而具有较好的水溶性和潜在的生物应用价值。我们给出了该纳米晶体的荧光激发谱与发射谱，详细说明了各发光峰对应能级的跃迁及其发光机理，分析了不同掺杂浓度对其荧光强度的影响。结果表明：所制备的纳米晶体在紫外光激发下，显示出明亮的绿色荧光。当卟“离子掺杂摩尔分数20％左右时，样品的荧光强度达到最大值。

英文摘要：

Recently, lanthanide-based nanocrystals have terials, considering their attractive optical and chemical showed great potential to be used as luminescent ma- features such as low toxicity, large effective Stokes shift and photochemical degradation. In this paper, we developed a simple method to prepare PEI coated CeF3： Tb3＋ nanocomposites in aqueous solution. The samples were characterized by transmission electron microscopy （ TEM）, X-ray diffraction （XRD） and Fourier prepared nanocrystals are hexagonal shaped transform infrared （FT-IR） spectra. The results show that all with an average size at around 10 nm and can also be used for covalently bonding to biomolecules. The products exhibit excellent green fluorescence under UV excitation. Further, the photoluminescence intensity is increased with the increasing doping concentration of the Tb3＋ and reached a maximum at approximately 20%.