文献类型：期刊文献

英文题名：Synthesis and characterization of SiO2-coated mercaptoacetic acid-stabilized CdSe nanocrystals in aqueous solution

作者：Chu, Mao-Quan[1]; Sun, Ye[2]; Shen, Xiao-Yan[3]; Liu, Guo-Jie[3]

机构：[1] Institute of Life Science and Technology, Tongji University, Shanghai, 200092, China; [2] Institute of Life Sicence and Technology, Shanghai Jiaotong University, Shanghai, 200032, China; [3] Department of Chemistry, East China University of Science and Technology, Shanghai, 200237, China

年份：2006

卷号：35

期号：1

起止页码：75

外文期刊名：Physica E: Low-Dimensional Systems and Nanostructures

收录：EI(收录号：20063910137667)

语种：英文

外文关键词：Cadmium compounds - Inorganic acids - Semiconductor quantum dots - Silica - Solutions - Synthesis (chemical) - Thermal effects - Transmission electron microscopy - X ray diffraction analysis

摘要：Mercaptoacetic acid-stabilized CdSe nanocrystals (NCs) coated with SiO2 shell have been prepared in aqueous solution at room temperature. The results showed that the characteristic UV-Vis absorption peak disappeared, the band-edge photoluminescent (PL) emission greatly increased and the surface state emission decreased after the CdSe core overcoating with SiO2 shell. The absorption spectra of the CdSe/SiO2 composites did not obviously change but the PL spectra continually varied with reaction time during, about, a month. The quantum yield of the CdSe/SiO2 composites was enhanced compared to the CdSe cores. Transmission electron microscopy (TEM) images revealed that multiple nanocores were incorporated in the spheres ranging in diameter mainly from 50 to 100 nm. Very aggregated spheres might be caused by the further hydrolysis of tetraethyl orthosilicate (TEOS). The X-ray diffraction (XRD) patterns also implied that the CdSe NCs had been incorporated in the SiO2 matrix. ? 2006 Elsevier B.V. All rights reserved.