NaYF4: Tb3+ , Yb3+ down-conversion (DC) phosphors were synthesized by hydrothermal method. X-ray diffraction (XRD), photoluminescence (PL) and photoluminescence excitation (PLE) spectra were used to characterize the samples. Experiment results revealed that samples of NaYF4: Tb3+ , Yb3+ crystallized in hexagonal shape without cubic shape. When the doping concentration of Tb3+ and Yb3+ was altered, the lattice structure of samples did not change, indicating that the Tb3+ and Yb3+ ions are completely dissolved in the NaYF4 host lattice by substitution for the y3+. The emission from 5D4→7F6 (489 nm), 5D4→7F5(542 nm), 5D4→7F4 (584 nm), and 5D4→F3 (619 nm) of Tb3+ ions was observed, in which the dominant emission was at 542 nm. With single Tb3+ doping, no near-infrared (NIR) emission was observed under excitation of 355 nm pulsed laser. However, while with Tb3+ and Yb3+ codoping, the NIR emission at around 950～1 100 nm from Yb3+ (2F5/2→2 F7/2 ) was observed under the same excitation. The dependence of the visible and NIR-emissions on Yb3+ doping concentration has been investigated. These results show that there is energy transfer process between Tb3+ and Yb3+. Furthermore, it is a possible DC process through cooperative energy transfer from Tb3+ to Yb3+. When the doping concentration is 1％ mol Tb3+ and 6％o mol Yb3+ respectively, the intensity of NIR emission reaches its strongest.%利用水热法合成了粉末发光材NaYF4:Tb3+,Yb3+分别用X射线衍射(XRD),光致发光谱(PL)和激发谱(PLE)测试了合成材料的物相结构和发光性质.研究结果表明:合成的NaYF4:Tb3+,Yb3+抖材料为六方相的品体,无立方相的.改变Tb3+和Yb3+的掺杂浓度后品格结构没有变化,说明离子Tb3+和Yb3+取代的是Y3+离子的品格位置.在355 nm脉冲激光激发下,检测到了Yb3+的5D→7FJ(J=5-0)和5D4→7FJ(J=6,5,4,3)可见波段特征发射光和Yb3+950～1 050 ms(2F5/2→2F7/2)的近红外发光,研究了可见和近红外的发射强度随Yb3+掺杂浓度的变化,表明Yb3+和Yb3+之间存在能理传递,其可能的能理传递方式是共合作能量传递过程.当Yb3+和Yb3+的掺杂摩尔浓度分别是1 mol%和6 mol%时具有最强的近红外发射.
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