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分别采用沉淀法和燃烧法制备了YAG:1%Eu3+纳米晶粉末,用XRD和TEM对样品进行了结构分析和形貌表征。室温光谱分析表明,其发射主峰位于590nm,来源于5 D0→7F1跃迁,另外来源于5 D0→7F4跃迁的709nm发射也较强。另外发现,燃烧法制备的样品在不同激发波长激发时,发射光谱峰形有显著变化。对沉淀法制备的纳米微粒经盐酸“浸蚀”表面修饰后,发现395nm激发时,676nm和693nm发光显著增强,而且693nm发射的激发谱中存在两个宽激发带。对表面修饰后样品的变温发光特性研究发现,随着温度的降低,676nm发射显著增强,而693nm发射显著减弱。对于上述现象通过纳米微粒的表面效应和缺陷态进行了分析和解释。
The YAG: 1% Eu3 + nanocrystalline powders were prepared by precipitation method and combustion method respectively. The structure and morphology of the samples were characterized by XRD and TEM. The results of the room temperature spectroscopy show that the main emission peak is located at 590 nm, originating from the 5 D0 → 7 F1 transition, and the emission from the 5 D0 → 7 F4 transition is also stronger at 709 nm. In addition, it was found that when the sample prepared by combustion method was excited at different excitation wavelengths, the peak shape of the emission spectrum changed significantly. The nano-particles prepared by the precipitation method were modified by hydrochloric acid “etching” surface and found that the luminescence of 676nm and 693nm was significantly enhanced at 395nm excitation, and there were two broad excitation bands in the excitation spectrum of 693nm emission. The study on the temperature-dependent luminescence characteristics of the surface-modified samples showed that the emission at 676 nm was significantly enhanced and the emission at 693 nm was significantly reduced with the decrease of temperature. The above phenomenon is analyzed and explained by the surface effect and defect state of the nanoparticles.