Gd^(3+),Yb^(3+)和Tm^(3+)共掺杂氟化物纳米晶中Yb^(3+)-Tm^(3+)-Gd^(3+)间的能量传递

Energy Transition Processes between Yb^(3+)-Tm^(3+)-Gd^(3+) in Gd^(3+),Yb^(3+) and Tm^(3+) Co-dopedg Fluoride Nanocrystal

用水热法合成了Y0.8-x-yF3∶Gd3x+,Yb30.+2,Tm3y+纳米晶的上转换发光材料。在典型的Y0.595F3∶Gd30.+200,Yb03.+200,Tm30.+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∶Gd3x+,Yb03.+2,Tm3y+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∶Gdx^3＋,Yb3＋0.2,Tm^3＋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,Tm^3＋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 Tm^3＋,make UV,violet,and blue UC emissions obtained,further,the 6IJ multiplets of Gd3＋ were populated through the energy transfer process 3P2→3H6（Tm^3＋）：8S7/2→6IJ（Gd3＋）.At the same time,the energy transfer processes occurred between Gd3＋ and Yb3＋ or Tm^3＋ based on the energy matching conditions,leading to the above mentioned UV UC emissions of Gd3＋.