Yb3+/Tm3+掺杂的NaY(WO4)2纳米晶的制备及发光特性

以聚乙二醇为配位剂,用水热法制备出纳米级上转换发光粉Yb3+和Tm3+共掺杂的NaY(WO4)2。研究了不同cYb/cTm对上转换发光强度的影响,实验表明当cYb/cTm=5∶1时,上转换发光强度最强。用XRD,SEM确定了Yb3+和Tm3+共掺杂的NaY(WO4)2是四方晶系,其粒径在25~35 nm范围,且分散均匀。用980 nm半导体激光器(LD)对其进行激发,在室温下观察到了365 nm附近紫外发射峰、456 nm,476 nm附近的蓝光发射峰和648 nm附近的红光发射峰,分别对应于Tm3+离子的1D2→3H6,1D2→3F4,1G4→3H6和1G4→3F4的跃迁。根据泵浦功率与发光强度的关系得出紫外发射峰、蓝光和红光发射均为双光子过程。

Preparation and Luminescence Property of Yb3+ and Tm3+ Co-Doped NaY(WO4)2 Nanocrystals

Using polyethylene glycol as Complexing agent,NaY(WO4)2 up-conversion luminescence nanocrystal co-doped Yb3+ and Tm3+ ions was synthesized by hydrothermal method.The effects of Yb/Tm molar concentra-tion ratio on Upconversion luminescence intensity was studied,and the experiments show that the Upconversion luminescence intensity is strongest when molar concentration ratio of Yb/Tm is 5∶1.Using XRD and SEM determined Yb3+ and Tm3+ co-doped NaY(WO4)2 is tetragonal crystal system,the particle size ranged from 25 nm to 35 nm and dispersed uniformly.The results show that ultraviolet emission peaking at 365 nm,blue emission peaking at 456 nm and 476 nm and red emission peaking at 648 nm corresponding to 1D2 → 3H6,1D2 → 3F4,1G4 → 3H6 and 1G4 → 3F4 transitions of Tm3+,respectively,were simultaneously observed at room temperature under 980 nm laser diode(LD) excitation.According to the relationship between the pump power and luminous intensity,ultraviolet emission peak,blue and red emission peak are the two-photon process.