稀土掺杂NaGdF_4纳米颗粒的制备与强近红外上转换特性

Synthesis and strong near-infrared upconversion characteristics in rare earth doped NaGdF_4 nanoparticles

采用水热法制备了高纯度六角相NaGdF4纳米颗粒,对样品的结构与形貌进行了表征。在980 nm激光激发下,研究了Yb3+/Tm3+共掺杂NaGdF4纳米颗粒的近红外上转换发光特性;分析了Yb3+/Tm3+共掺杂NaGdF4的能量传递机理,研究了泵浦功率与发光强度的关系。结果表明:共掺杂NaGdF4纳米颗粒在980 nm下可发射出800 nm的强近红外光,其与475 nm蓝光发射的强度比为42。样品中800 nm发射对应两光子过程,475 nm发射对应三光子过程。

Hexagonal NaGdF4 nanoparticles were prepared by hydrothermal synthesis method, and the structure and morphology of the samples were characterized. Radiated by laser at the wavelength of 980 nm, near-infrared upconversion luminescence properties of Yb3 ＋ / Tm3＋ doped NaGdF4 nanoparticles were examined. The energy transfer mechanism was analyzed, and the relationships between the pump light power and the fluorescence intensity were exmined. The results show that the doped NaGdF4 nanoparticles can emit the strong near- infrared light of the wavelength of 800 nm when they were radiated by laser at the wavelength of 980 nm, with the ratio of 42, compared with the intensity of the blue light emission. In samples, the 800 nm emission corresponds to the two-photon process, and the 475 nm emission corresponds to the three-photon process.