Grupo de Pesquisa em Química de Materiais - (GPQM), Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, São João Del Rei, Minas Gerais, 36301-160, Brazil.
Nanoscale Res Lett. 2012 Sep 27;7(1):536. doi: 10.1186/1556-276X-7-536.
We investigate systematically the influence of the nature of thiol-type capping ligands on the optical and structural properties of highly luminescent CdTe quantum dots synthesized in aqueous media, comparing mercaptopropionic acid (MPA), thioglycolic acid (TGA), 1-thioglycerol (TGH), and glutathione (GSH). The growth rate, size distribution, and quantum yield strongly depend on the type of surface ligand used. While TGH binds too strongly to the nanocrystal surface inhibiting growth, the use of GSH results in the fastest growth kinetics. TGA and MPA show intermediate growth kinetics, but MPA yields a much lower initial size distribution than TGA. The obtained fluorescence quantum yields range from 38% to 73%. XPS studies unambiguously put into evidence the formation of a CdS shell on the CdTe core due to the thermal decomposition of the capping ligands. This shell is thicker when GSH is used as ligand, as compared with TGA ligands.
我们系统地研究了巯基型封端配体的性质对在水相介质中合成的高发光 CdTe 量子点的光学和结构性质的影响，比较了巯基丙酸（MPA）、巯基乙酸（TGA）、1-巯基甘油（TGH）和谷胱甘肽（GSH）。生长速率、尺寸分布和量子产率强烈依赖于所用表面配体的类型。虽然 TGH 与纳米晶表面结合得太强，从而抑制了生长，但使用 GSH 会导致最快的生长动力学。TGA 和 MPA 表现出中等的生长动力学，但 MPA 的初始尺寸分布比 TGA 低得多。所得到的荧光量子产率范围从 38%到 73%。XPS 研究明确证明了由于封端配体的热分解，在 CdTe 核上形成了 CdS 壳。与使用 TGA 配体相比，当使用 GSH 作为配体时，该壳层更厚。
