YLiF_4:Er^(3+),Tm^(3+),Yb^(3+)中Tm^(3+)浓度对上转换发光的影响

Tm^(3+) Concentration Dependence of Upconversion Intensity of YLiF_4:Er^(3+),Tm^(3+),Yb^(3+)

利用水热法合成了YLiF4:Er3+,Tm3+,Yb3+,其中Er3+和Yb3+的浓度保持固定不变,分别为1 mol%和1.5 mol%,Tm3+浓度变化范围是2 mol%~8 mol%。在这种共掺杂体系中,同时观察到了Er3+,Tm3+和Yb3+的吸收,且Tm3+的吸收随着其浓度的增强而增强。在980 nm光的激发下,当Tm3+浓度很小时,这种材料的上转换发光为白光。其中蓝光主要来源于Tm3+的激发态1G4到基态3H6的跃迁,绿光来源于Er3+的4S3/2和2H11/2到基态4I15/2的跃迁,红光既来源于Tm3+的1G4→3F4的跃迁,也来源于Er3+的4F9/2→4I15/2的跃迁。并且这种上转换发光强度随着Tm3+浓度的增强而降低,但对应不同能级跃迁的发光强度降低的幅度不同,这是因为Er3+和Tm3+之间的相互作用。

A series of YLiF4：Er^3＋,Tm^3＋,Yb^3＋ samples were synthesized by hydrothermal method. The concentrations of Er^3＋ and Yb^3＋ were 1 mol% and 1.5 mol%, respectively. Tm^3＋ concentration changed from 2 to 8 mol%. The absorption of Er^3＋ , Tm^3＋ and Yb^3＋ were observed, and the absorption of Tm^3＋ increased along with the increase in Tm^3＋ concentration. The color of upconversion luminescence of YLiF4：Er^3＋,Tm^3＋ and Yb^3＋ excited by 980 nm was white when Tm^3＋ concentration was low. The blue light resulted from the transition of ^1G4→^3H6 of Tm^3＋ , the green light from the transition of ^4S（3/2） （^2H（11/2）→^4I（15/2） of Er^3＋ ,and the red light from the transitions ^1G4→^3F4 of Tm^3＋ and ^4F（9/2）→^4I（15/2） of Er^3＋. All the upconversion intensities decreased when Tm^3＋ concentration increased, but the relative intensity decrease was different due to the interaction between Er^3＋ and Tm^3＋.