反相微乳液法制备CdS/ZnS纳米晶及其表征  

Preparation and Characterization of CdS/ZnS Nanocrystals in Microemulsions

作　　者：聂波[1] 张建成[1] 沈悦[1] 李思鑫[1] 张金刚[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《人工晶体学报》2006年第3期588-593,共6页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.90206017);国家科技攻关项目(No.2003BA301A21)

摘　　要：用反相微乳液法制备了CdS纳米粒子,以ZnS对其表面进行包裹,得到了核壳结构的CdS/ZnS纳米晶。采用X射线衍射(XRD)、透射电镜(TEM)表征其结构、粒度和形貌,紫外-可见吸收光谱(UV-VIS)、光致发光光谱(PL)表征其光学特性。制得的CdS纳米微粒近似呈球形,直径约3.6nm;包裹以后颗粒仍为球形,粒径约10nm,以XRD、UV-VIS和PL证实了CdS/ZnS核壳结构的实现。文章还研究了不同Zn/Cd的摩尔比对CdS/ZnS纳米微粒光学性能的影响,UV-VIS谱表明随着壳层厚度的增加CdS/ZnS纳米晶的吸收带边有轻微的红移;PL谱表明壳层ZnS的包覆可减少CdS纳米微粒的表面缺陷,带边直接复合发光几率增大,且具有合适的壳层厚度时,CdS核层的发光效率有较大提高。CdS nanocrystals and CdS/ZnS core-shell structure nanocrystals were synthesized in microemulsion, and characterized by X-ray diffraction （ XRD）, transmission electron microscopy （ TEM）, UV-VIS absorption spectra and photoluminescence （PL）. The average diameter of CdS nanocrystals and CdS/ZnS core-shell structure nanocrystals are about 3.6nm and 10nm, respectively, and CdS/ZnS coreshell structure was confirmed by XRD and UV-VIS. Being considered the optical properties of CdS/ZnS core-shell structure nanocrystals with a different ratio of Zn/Cd, the UV-VIS absorption edge of CdS/ZnS becomes a slight red-shift with the increasing of the thickness of ZnS layer. The PL spectra indicate that ZnS shell layer can greatly eliminate surface defects of CdS nanocrystals to make the increasing of the direct recombination of their band-edge, and the photoluminescence efficiency of CdS is improved greatly when they have an appropriate shell thickness.

关 键 词：CDS ZNS 核壳结构 纳米晶 反相微乳液 

分 类 号：O472[理学—半导体物理]