用水热法合成了Y0.8-x-yF3∶Gd3+x,Yb3+0.2,Tm3+y纳米晶的上转换发光材料。在典型的Y0.595F3∶Gd3+0.200,Yb3+0.200, Tm3+0.005纳米微晶中, 在980 nm激光激发下, 观察到了Tm3+的紫外、紫色上转换发射明显增强和来自于Gd3+的6D9/2、6IJ、6P5/2及6P7/2能级到基态8S7/2能级的紫外发射。通过比较Y0.8-x-yF3∶Gd3+x,Yb3+0.2,Tm3+y纳米晶样品的上转换发光性质以及Tm3+和Gd3+中一些激发态的能级寿命, 借助于能级图描述了Yb3+-Tm3+-Ga3+之间的有效的能量传递过程。

Y0.8-x-yF3∶Gd3+x, Yb3+0.2,Tm3+y nanocrystals were synthesized through a hydrothermal method. The upconversion(UC) emission properties under a 980 nm continuous wave semiconductor laser diode excitation were studied. The experimental results suggested that the violet and ultraviolet(UV) UC emission enhancement were observed in Y0.595F3∶Gd3+0.200,Yb3+0.200,Tm3+0.005 nanocrystal,as well as the UC emissions of Gd3+ of 6D9/2,6IJ,6P5/2,and 6P7/2 states to the ground state 8S7/2 were shown,too. The luminescent kinetic analysis implied that,under 980 nm excitation,Yb3+ can transfer energy to populate the 3P2 level of Tm3+,make UV,violet,and blue UC emissions obtained,further,the 6IJ multiplets of Gd3+ were populated through the energy transfer process 3P2→3H6(Tm3+)：8S7/2→6IJ(Gd3+). At the same time,the energy transfer processes occurred between Gd3+ and Yb3+ or Tm3+ based on the energy matching conditions, leading to the above mentioned UV UC emissions of Gd3+.