Glasses Tech

September 22, 2009

The Preparation of CdS Particles in Silica Glasses by a Sol-Gel Method

Filed under: Glasses 1995 — admin @ 3:09 am

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The sol-gel process has been successfully applied to the preparation of a small-particle-size CdS-doped silica matrix with a significant quantum size effect. Transparent and colorless gels were prepared through the hydrolysis of a complex solution of Si(OC2H5)4, (CH3)2SO, and Cd(CH3COO)2 · 2H2O. These gels were heated at 350, 500, 750, and 1000℃ to form fine, hexagonal, CdS-microcrystal-doped glasses. The thermal treatments of samples were established by TDA/TGA analysis. Structural evolution of alkoxide silica during densification was followed by infrared spectroscopy. Samples were characterized using X-ray diffraction. The absorption spectra have also been measured and indicate the potential application of this material in optical devices. A simple quantum mechanical model has been used to calculate the particle size from the absorption onset measured for CdS in the SiO2 matrix. The result is interpreted in terms of a quantum confinement effect of small crystal size.

E. Cordoncillo, P. Escribano, G. Monros, M. A. Tena, V. Orera and J. Carda
Department of Experimental Sciences, Universitat Jaume I, Castellan, Spain; and Materials Science Institute, Universidad de Zaragoza-CSIC, Zaragoza, Spain

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