文献类型：期刊文献

英文题名：Layer-by-layer aqueous synthesis, characterization and fluorescence properties of type-II CdTe/CdS core/shell quantum dots with near-infrared emission

作者：Gui, Rijun[1,2]; An, Xueqin[1]

机构：[1] School of Chemistry and Molecules Engineering, East China University of Science and Technology, Shanghai 200237, China; [2] School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China

年份：2013

卷号：3

期号：43

起止页码：20959

外文期刊名：RSC Advances

收录：EI(收录号：20134316903504)

语种：英文

外文关键词：Shells (structures) - II-VI semiconductors - Semiconductor quantum dots - Chlorine compounds - Passivation - Solutions - Cadmium sulfide - Infrared devices - Zinc sulfide - Nanocrystals - Medical applications

摘要：A layer-by-layer epitaxial method was developed to synthesize water-soluble, near-infrared (NIR)-emitting type-II core/shell CdTe/CdS quantum dots (QDs) via employing glutathione-capped CdTe QDs as core templates, CdCl2 and thiourea as shell precursors. CdTe/CdS type-II nanostructure yields the QDs with NIR emission by varying the size of CdTe cores and the thickness of CdS shells. Compared to CdTe core QDs, CdTe/CdS core/shell QDs exhibit remarkable red-shifted spectra, and the corresponding emission maximum wavelength can span from 626 to 809 nm. Surface passivation of ZnS shell with a substantially wide bandgap restrains the excitons within CdTe/CdS QDs interface and isolates them from aqueous solution. This passivation therefore improves the photoluminescence (PL) efficiency of the CdTe/CdS nanostructure, including PL quantum yield, lifetime and photo-stability/catalytic activity. Through comprehensive research on their core/shell nanostructures, the CdTe/CdS QDs obtained from hydrothermal shell-coating route, show good monodispersity, lattice-mismatched heterostructure and NIR-emission properties, offering a great potential for biological or biomedical applications. ? The Royal Society of Chemistry 2013.