YLiF4: Er3+, Tm3+, Yb3+中Tm3+浓度对上转换发光的影响

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.

Tm3+ Concentration Dependence of Upconversion Intensity of YLiF4:Er3+, Tm3+, Yb3+

A series of YLiF4: Er3+ , Tm3+ , Yb3+ samples were synthesized by hydrothermal method. The concentrations of Er+ and Yb3+ were 1 mol% and 1.5 mol%, respectively. Tm3+ concentration changed from 2 to 8 mol%. The absorption of Er3+, Tm3+ and Yb3+ were observed, and the absorption of Tm3+ increased along with the increase in Tm3+ concentration. The color of upconversion luminescence of YLiF4: Er3+, Tm3+ and Yb3+ excited by 980 nm was white when Tm3+ concentration was low. The blue light resulted from the transition of 1G4-->3H6 of Tm3+, the green light from the transition of 4S(3/2)(2H(11/2))-->4I(15/2) of Er3+, and the red light from the transitions 1G4-->3F4 of Tm3+ and 4F(9/2)-->4I(15/2) of Er3+. All the upconversion intensities decreased when Tm3+ concentration increased, but the relative intensity decrease was different due to the interaction between Er3+ and Tm3+.