微乳液法制备NaYF_4∶Yb^(3+),Er^(3+)粉体及其发光性能

Preparation and Luminescence Properties of NaYF_4Yb^(3+),Er^(3+) Powder by Microemulsion Method

采用微乳液法制备了纯相立方和六方晶相NaYF4∶Yb3+,Er3+发光材料,微乳液体系选择了CTAB(十六烷基三甲基溴化铵)-正丁醇-正辛烷-水。研究了NaF/Y3+比例、反应温度、反应时间和体系pH值等对相形成的影响,以及陈化、后续热处理温度和时间对颗粒尺寸和发光性能的影响。结果表明:在NaF/Y3+比例小于5、体系pH=5~6、反应温度为140℃、反应时间为24 h的条件下,可得到立方相α-NaYF4∶Yb3+,Er3+,粒径约为200 nm;在NaF/Y3+比例大于5、体系pH=1~4、反应温度为160℃、反应时间为60 h以上的条件下,可得到六方相β-NaYF4∶Yb3+,Er3+,粒径约为1μm。样品在980 nm激光激发下,在521,529,541,549 nm处有发光峰,最强发光峰为541 nm,表现为明亮的绿色。

Ytterbium(Ⅲ),erbium(Ⅲ) co-doped sodium yttrium fluoride(NaYF4∶ Yb3 +,Er3 +) powder were prepared by microemulsion method. CTAB(Cetyltrimethyl ammonium bromide), n-butyl alcohol,n-octane and water were selected as the microemulsion system. The influence of NaF/Y3 +ratio,reaction temperature,reaction time,pH value,aging time,and heat treatment on phase formation,luminous efficiency and the particle size were studied. The results indicate that α-NaYF4∶ Yb3 +,Er3 +samples can be obtained at 140 ℃ for 24 h with the optimal pH = 5 ~ 6,and β-NaYF4∶ Yb3 +,Er3 +samples can be obtained at 160 ℃ for 60 h with the optimal pH = 1 ~ 4. The particle sizes of α-NaYF4∶ Yb3 +,Er3 +and β-NaYF4∶ Yb3 +,Er3 +are 200 nm and 1 μm,respectively. Excited by 980 nm LD,the samples emit bright green light peaking at 521,529,541,549 nm,and 541 nm is the strongest.