四方相LiY(Yb)F_4:Yb^(3+)/Er^(3+)晶体颗粒的合成及上转换荧光光谱

Synthesis of tetragonal-phased LiY(Yb)F_4:Yb^(3+)/Er^(3+) crystal particles and the upconversion luminescence spectrum

采用水热法分别合成了四方相LiYF4:Yb3+/Er3+和LiYbF4:Yb3+/Er3+的八面体晶体颗粒,并通过XRD,SEM,荧光光谱观测等手段对其晶相、形貌及上转换荧光效应等进行了研究.结果表明,EDTA(乙二胺四乙酸)表面活性剂的引入导致了样品平均粒径和结晶度的变化及发光强度等的变化.在波长为980nm激光的激发下,观测到了源于2H11/2→4I15/2和4S3/2→4I15/2跃迁的绿色上转换荧光发射、4F9/2→4I15/2跃迁的红光发射和2H9/2→4I15/2跃迁所产生的微弱紫光发射;分析了上转换发光机理和基质变化对上转换荧光性质的影响.

Tetragonal-phased LiYF4：Yb3＋/Er3＋ and LiYbF4 ：Yb^3＋ /Er^ 3＋ crystal particles with octagonal morphology are prepared by hydrothermal method and characterized with XRD and SEM. The up-conversion fluorescence was studied with spectroscopic method. The results showed that crystallization and particle size was adjusted by introducing EDTA （ethylenediaminetetraacetic acid）, which finally introduced the change of fluorescence intensity. Green fluorescence emissions from 4^S3/2 → 4^I15/2 and 2^H11/2 → 4^I15/2 transitions, violet emission from 2^H 9/2 → 4I15/2 transition, and red emission from ^4F9/2→4^I15/2 were observed when the samples were excited with 980 nm IR laser. Meanwhile, the mechanism and the influence of the host matrix on the upconversion fluorescence emission were discussed.