CdSe:Nd纳米晶及CdSe:Nd@SiO_2核壳结构的合成及发光性能  

Synthesis and Fluorescence Properties of CdSe:Nd and CdSe:Nd@SiO_2 Core-Shell Structures

作　　者：杨峻宏 张高峰 高俊芳[1] 雍胜利[1] 马学林[1] 段军 YANG Jun-hong;ZHANG Gao-feng;GAO Jun-fang;YONG Sheng-li;MA Xue-lin;DUAN Jun(Department of Chemistry,Baotou Teachers College,Baotou 014030,China)

机构地区：[1]包头师范学院化学学院,内蒙古包头014030

出　　处：《发光学报》2018年第9期1260-1267,共8页Chinese Journal of Luminescence

摘　　要：利用有机相法合成Nd^(3+)掺杂CdSe纳米晶(CdSe:Nd),通过X射线粉末衍射(XRD)、透射电镜(TEM)、紫外吸收光光谱及荧光光谱表征,证明Nd^(3+)已经成功掺入到CdSe的晶格中。与纯CdSe纳米晶相比,CdSe:Nd纳米晶的结构仍为立方晶型,且形貌近似球形,均匀分散,粒径约为2~4 nm。紫外吸收峰和荧光发射峰都发生红移,而且掺杂后的CdSe:Nd纳米晶量子产率也提高,这可能是由于掺杂Nd^(3+)引入了新的杂质能级,带隙减小。为了实现CdSe:Nd纳米晶的可加工性和功能性,通过微乳法合成SiO_2壳包覆的CdSe:Nd纳米球(CdSe:Nd@SiO_2纳米球),CdSe:Nd@SiO_2纳米球呈均匀球形,直径约为100~115 nm,并且包壳后的CdSe:Nd@SiO_2纳米球发射峰(581 nm)与CdSe:Nd纳米晶(598 nm)相比,发光强度提高且发射峰蓝移,蓝移约为17 nm,可能是因为SiO_2壳可以减少纳米晶表面的非辐射跃迁以及改善表面缺陷导致的。Nd nanocrystals(CdSe∶Nd NCs)were synthesized via organic phase method.The objective of this research was to investigate structure,microstructure,optical properties and possible luminescence mechanism of CdSe∶Nd and CdSe∶[e-mail] is confirmed that Nd3+is successfully incorporated into the crystal lattice of CdSe through XRD,TEM,UV-visible absorption spectroscopy and fluorescence emission.Compared with pure CdSe NCs,CdSe∶Nd NCs still have a cubic crystal structure,the lattice constant of CdSe and CdSe∶Nd NCs is 0.605 and 0.609 nm,respectively.The lattice of CdSe∶Nd constant increases,it may be due to the ionic radius of Nd^3+is larger than Cd^2+.When Nd^3+is incorporated into the crystal lattice of CdSe∶Nd NCs,which results in dilation of crystal lattice.CdSe∶Nd NCs are monodisperse and spherical particles with an average diameter of 2-4 nm.Both absorption spectrum and emission spectrum red-shift,and the quantum yields of the CdSe∶Nd NCs also increase,which may be due to the introduction of new impurity levels and the decrease of the band gap.To enhance the stability and functionality of CdSe∶Nd NCs,CdSe∶Nd NCs were coated with SiO2(CdSe∶Nd@SiO2 spheres)and the core-shell SiO2-coated CdSe∶Nd NCs(CdSe∶Nd@SiO2)were prepared via the micro-emulsion method.XRD patterns show that the patterns of CdSe∶Nd@SiO2 contain the characteristic peak of CdSe∶Nd NCs,which proves that CdSe∶Nd has entered in the SiO2 shell successfully.CdSe∶Nd NCs are uniform spherical with an average diameter of 100-115 nm,and CdSe∶Nd NCs can be clearly seen in the SiO2 shell.The fluorescence emission of CdSe∶Nd@SiO2(581 nm)shows a blue-shift compared with CdSe∶Nd NCs(598 nm),possibly because of altered surface properties and reduction of nonradiative transitions.

关 键 词：CdSe∶Nd纳米晶 掺杂 CdSe∶Nd@SiO2纳米球 荧光性质 核壳 

分 类 号：O482.31[理学—固体物理] O635[理学—物理]