摘要
利用水热法合成了氟化物Y0.795-xGdxYb0.2Tm0.005F3(x=0.0,0.1,0.2,0.5,0.8)纳米晶。研究了退火后系列样品的上转换发光性质以及激发态辐射跃迁寿命。在980nm激发下,Y0.795-xGdxYb0.2Tm0.005F3纳米微晶样品中观察到了Tm3+的蓝光上转换发射及紫色、紫外发射增强现象,同时还观察到Gd3+的6D9/2、6IJ、6P5/2及6P7/2到基态8S7/2的发射。实验结果表明:样品半个波长量级的颗粒尺寸是Tm3+紫外上转换增强以及Tm3+到Gd3+发生有效能量传递的重要因素。
Y0.795-x GdxYb0.2 Tm0.005 F3 nanocrystals were synthesized through a hydrothermal method. After annealing in the air conditions, 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 Y0.795-xGdxYb0.2Tm0.005F3 nanocrystals, as wall as the UC emissions from ^6D9/2, 6IJ, ^6P5/2, and ^6P7/2 states to the ground state ^8S7/2 of Gd^3+ were shown, too. The luminescent kinetic analysis implied that, under 980 nm excitation, Yb^3+ can transfer energy to populate the 3 P2 level of Tm^3+ , make UV, violet, and blue UC emissions obtained, further, the ^6IJ multiplets of Gd^3+ were populated through the energy transfer process 3 p2→^ 3 H6 (Tm^3+ ) :^8S7/2 →^ 6IJ ( Gd^3+ ). At the same time, the energy transfer processes occurred between Gd^3+ and Yb^3+ or Tm^3+ based on the energy matching conditions, leading to the above mentioned UV UC emissions of Gd^3+.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2009年第6期738-743,共6页
Chinese Journal of Luminescence
基金
国家自然科学基金(10774142)资助项目
关键词
稀土
氟化物
纳米晶
上转换发射
rare earth
fluoride
nanocrystal
up-conversion emission