Spontaneous CdTe Alloy CdS Transition of Stabilizer-Depleted CdT
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- 作者：Zhiyong Tang ; Ying Wang ; Sachin Shanbhag ; and Nicholas A. Kotov
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：May 31, 2006
- 年：2006
- 卷：128
- 期：21
- 页码：7036 - 7042
- 全文大小：485K
- 年卷期：v.128,no.21(May 31, 2006)
- ISSN：1520-5126
文摘
CdTe nanoparticles stabilized by L-cysteine are chemically transformed into CdS nanoparticlesof the same diameter via an intermediate CdTeS alloy without any auxiliary source of sulfur. The reactionis induced by ethylenediaminetetraacetic acid dipotassium salt dehydrate (EDTA), which was demonstratedexperimentally to act as a catalyst by partially removing thiol stabilizers from the nanoparticle surface. It ishypothesized that addition of EDTA facilitates Te2- release, and oxidation of Te2- drives the nanoparticletransition process. Unlike many reports on reactions catalyzed by nanocolloids, this is likely to be the firstobservation of a catalytic reaction in which nanoparticles function as a substrate rather than a catalyst. Itopens new pathways for the synthesis of novel nanoscale II-VI and other semiconductors and representsan interesting case of chemical processes in nanocolloids with reactivity increased by depletion of thesurface layer of thiol stabilizers. This includes but is not limited to accurate control over the particlecomposition and crystallization rate. The slow rate of the CdTe 
alloy CdS transition is important forminimizing defects in the crystal lattice and results in a substantial increase of the quantum yield ofphotoluminescence over the course of the transition.
alloy CdS transition is important forminimizing defects in the crystal lattice and results in a substantial increase of the quantum yield ofphotoluminescence over the course of the transition.