溶胶-凝胶法制备Sr2SiO4:Tb3+绿色荧光粉及其发光性能

A study on the preparation and the luminescent property of Sr2SiO4: Tb3+ green phosphor by the sol-gel method

  • 摘要: 采用溶胶-凝胶法合成了一系列适合紫外-近紫外激发的(1-X)Sr2SiO4:XTb3+(X=0,0.01,0.02,0.03,0.04,0.05,0.06)绿色荧光粉,并采用X射线衍射(XRD)、扫描电子显微镜(SEM)和荧光光谱(PL)研究了样品的结构及发光性能.由XRD的检测结果可知,合成样品属于单斜晶系的β-Sr2SiO4相.由SEM图可知,所有样品都呈无规则块状结构.当监测波长为546 nm,样品的激发光谱的主峰位于370 nm处,属于Tb3+的4f-4f特征跃迁吸收.当激发波长分别为285 nm和250 nm,所有样品在488 nm,547 nm,586 nm,623 nm处都出现了1个强发射峰,分别对应Tb3+5D47F65D47F55D47F45D47F3电子跃迁.最强发射峰位于547 nm处,呈现特征为绿光发射.随Tb3+掺杂量增大,发射强度呈现出先增大后减小的变化趋势,即存在浓度猝灭效应.当Tb3+掺杂量为X=0.03时,样品的发光强度最大.

     

    Abstract: A series of(1-X)Sr2SiO4:XTb3+(X=0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06) green phosphors were synthesized by the sol-gel method, which weresuitable for UV and near-UV excitation. The structure and the luminescence properties of phosphors were characterized by X-ray diffraction, scanning electron microscopy and fluorescence spectra. The results of XRD show that the synthesized samples belong to the monoclinic β-Sr2SiO4 phase.It can be seen from the SEM diagram that all synthesized samples are presented as irregular block structures. The main excitation peak of Sr2SiO4:Tb3+ phosphor appears at 370 nm when the monitoring waveleng this 547 nm, which belongs to the 4f-4f characteristic transition absorption of Tb3+. The emission spectra of Sr2SiO4:Tb3+phosphors shows four strong emission peaks at 488 nm, 547 nm, 586 nm, 623 nm, which originates from 5D47F6, 5D47F5, 5D47F4 and 5D47F3 transitions of Tb3+when the excitation wavelengths are 285 nm and 250 nm, respectively. The strongest emission peak appears at 547 nm, characterized by green light emission.With the increase of doping amount of Tb3+, the emission intensity shows a trend of decreasing after increasing at the beginning period, that is, there is a concentration quenching effect. The luminous intensity of the sample is the strongest when the Tb3+ doping amount is X=0.03.

     

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