钕敏化多层壳纳米结构的增强型染料敏化上转换发光  

Enhanced dye-sensitized up-conversion luminescence of neodymium-sensitized multi-shell nanostructures

作　　者：王丹[1,2,3] 薛彬 涂浪平[3] 张友林 宋军[1] 屈军乐[1] 孔祥贵[3] WANG Dan;XUE Bin;TU Lang-ping;ZHANG You-lin;SONG Jun;QU Jun-le;KONG Xiang-gui(Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education/Guangdong Province,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China;College of Information Engineering,Shenzhen University,Shenzhen 518060,China;State Key Laboratory of Luminescence and Applications,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]深圳大学物理与光电工程学院光电子器件与系统教育部/广东省重点实验室,广东深圳518060 [2]深圳大学信息工程学院,广东深圳518060 [3]中国科学院长春光学精密机械与物理研究所发光学及应用国家重点实验室,吉林长春130033

出　　处：《中国光学》2021年第2期418-430,共13页Chinese Optics

基　　金：国家重点基础研究发展计划(No.2018YFC0910602);国家自然科学基金项目(No.61605130,No.11604331,No.61775145,No.61835009);吉林省科技厅自然科学基金项目(No.20180101222JC);深圳市基础研究项目(No.JCYJ20180305125425815)。

摘　　要：对于稀土离子掺杂的上转换发光,由于稀土离子吸收截面小、吸收范围窄,导致其发光强度受限。最近,在稀土上转换纳米粒子的表面连接近红外染料分子敏化发光,被证实是提高上转换发光强度的有效策略。然而,将染料分子连接经典的稀土Yb掺杂纳米粒子,并不能有效利用染料分子的敏化能力。针对这一问题,本文通过高温热分解法成功制备了Nd^(3+)敏化的核/壳/壳(NaYF_(4):Yb/Er(20/2%)@NaYF_(4):Yb(10%)@NaYF_(4):Nd(80%))纳米结构,与经典的IR-806敏化的NaYF_(4):Yb/Er纳米结构相比,IR-806敏化的Nd^(3+)掺杂的核/壳/壳纳米结构的上转换发光(500~700 nm)强度增强了约38倍。通过荧光光谱及荧光寿命分析证实,上转换发光强度增强源于Nd的吸收与近红外染料分子的有效交叠,以及壳层结构对发光中心的保护作用(Er^(3+)(^(4)S_(3/2)→^(4)I_(15/2))的寿命延长了1.7倍)。另外,研究发现纳米壳层结构中最外层掺杂的Yb^(3+)离子将导致染料敏化发光减弱。进一步,这种IR-806敏化的Nd掺杂的核/壳/壳纳米结构可实现增强发光中心为Ho及Tm的上转换发光。本文研究为提高染料敏化上转换发光及应用提供了新途径。Lanthanide-ion-doped upconversion luminescence is limited by the small absorption cross-section and narrow absorption band of lanthanide ions,which results in weak luminescence.Recently,a dye-sensitized method has proven to be an effective strategy of increasing upconversion luminescence.However,simply attaching dye molecules to nanoparticles with classic Yb-doped nanostructures cannot effectively activate the sensitizing ability of the dye molecules.In response to this problem,we designed Nd-sensitized core/shell/shell(NaYF_(4):Yb/Er(20/2%)@NaYF_(4):Yb(10%)@NaYF_(4):Nd(80%))nanostructures,compared with the classic IR-806 sensitized NaYF_(4):Yb/Er nanostructure,their upconversion luminescence(500 to 700 nm)was approximately enhanced by a factor of 38.Through analysis of the nanostructure’s emission and luminescence lifetime data,the enhancement was confirmed by the effective overlap of Nd absorption with the emission of near-infrared dye molecules and the protective effects of the shell structure on the luminescent center(the lifetime of Er(^(4)S_(3/2)→^(4)I_(15/2))was increased by 1.7 times).In addition,we found that the doping Yb^(3+)in the outermost layer will decrease the dye-sensitized luminescence intensity.Furthermore,this Ndsensitized core/shell/shell structure also achieved enhancement in the sensitized upconversion luminescence of the luminescence centers of Ho and Tm,which establishes a foundation for enhanced dye-sensitized upconversion luminescence.

关 键 词：上转换发光 稀土离子 染料敏化 纳米粒子 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]