1. Synthesis of high quality and stability CdS quantum dots with overlapped nucleation-growth process in large scale
- Author
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Liu, Xinmei, Jiang, Yang, Lan, Xinzheng, Li, Shanying, Wu, Di, Han, Tingting, Zhong, Honghai, and Zhang, Zhongping
- Subjects
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NUCLEATION , *CADMIUM sulfide , *QUANTUM dots , *PHOTOLUMINESCENCE , *TRANSMISSION electron microscopy , *X-ray diffraction , *PARTICLE size distribution - Abstract
Abstract: A low-cost, green, and reproducibly non-injection one-pot synthesis of high-quality CdS quantum dots (QDs) is reported. The synthesis was performed in the open air by mixing precursors cadmium stearate and S powder into a new solvent N-oleoylmorpholine. An overlapped nucleation-growth stage followed by a dominated growth stage was observed. The resulting QDs exhibited well-resolved absorption fine substructure and a dominant band-edge emission with a narrow size distribution (the full width at half maximum (fwhm) was only 22–24nm). The maximum photoluminescence (PL) quantum yield (QY) was as high as 46.5%. Highly monodispersed CdS QDs with tunable sizes and similar PL fwhm and QYs could also be obtained from the CdS QDs in a large-scale synthesis. The high-resolution transmission electron microscopy (HRTEM) images and powder X-ray diffraction (XRD) pattern suggested that the as-prepared QDs with high crystallinity had a cubic structure. A significant PL improvement and a continuous QY increase for the CdS QDs were observed during a long storage time in air and in a glovebox under room temperature. A slow surface reconstruction was proposed to be the cause for the PL enhancement of CdS QDs. [Copyright &y& Elsevier]
- Published
- 2011
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