GdF_3∶Eu^(3+)纳米晶的VUV荧光性质  

VUV Luminescent Properties of GdF_3∶Eu^(3+) Nanocrystals

作　　者：华瑞年[1] 牛晶华[1] 李文连[1] 李明涛[1] 俞天智[1] 初蓓[1] 

机构地区：[1]中国科学院激发态物理重点实验室,吉林长春130033

出　　处：《发光学报》2005年第5期684-686,共3页Chinese Journal of Luminescence

基　　金：国家自然科学基金(90201012);中科院长春光机与物理所青年创新基金(Q03M18Z)资助项目

摘　　要：利用微乳液水热法制备出GdF3∶Eu3+纳米晶及纳米棒。用X射线粉末衍射(XRD)和透射电子显微镜(TEM)等手段对材料的结构、形态及粒径大小等进行了表征。室温下真空紫外(VUV)光谱及荧光光谱表明GdF3∶Eu3+纳米晶中的Gd3+离子吸收一个光子,并将能量分两步传递给Eu3+,发生了双光子发射。从各跃迁的积分强度和量子效率表达式可以得到材料在160 nm紫外光激发下的量子效率约为170%。Abstract： One of the important challenges in luminescent material research nowadays is to development of new phosphors under excitation with the vacuum ultraviolet spectral region （ VUV, E 〉 50 000 cm^-1, λ 〈 200 nm）. The VUV phosphors used in mercury fluorescent tubes have high quantum effieiencies closing to 100%. Therefore, to make a noble gas discharge fluorescent tube a competitive phosphor with higher quantum efficiencies than 100% , i.e. more than one visible photon should be obtained per absorbed VUV photon. This phenomenon is called quantum cutting. The goal of our research is to find an more efficient visible quantum cutter. In order to achieve this, GdF3： Eu^3＋ nanocrystals and nanorods were synthesized by micromulsion-mediated hydrothermal process. The structure, shape and particles size were characterized by means of XRD, and TEM. VUV excitation spectra of GdF3： Eu^3＋ nanocrystals showing that the Gd^3＋ ion can absorb one VUV photon and was excited into the ^6GJ level, and then the ^6GJ level relaxes to transfer the energy to Eu^3＋ ion by two-step energy decaying processes, yielding two visible photons at room temperature. The visible quantum efficiency of GdF3： Eu^3＋ NCs was calculated to be close to 170% by correlative transition emission peaks intensity ratio under VUV excitation at 160 nm.

关 键 词：GdF3:Eu^3+ 纳米晶 量子剪裁 量子效率 

分 类 号：O482.31[理学—固体物理]