Cds Quantum Dots: Aqueous Synthesis, Spectroscopic and Microscopic Investigation

Investigating the Synthesis and Properties of Cadmium Sulfide Quantum Dots

Abstract

The spherical shape CdS quantum dots with cubic zincblend phase were synthesized through aqueous route using cadmium chloride andthiourea as cadmium and sulfur source and thioglycolic acid as a stabilizingagent. The size regime of the CdS quantum dots is in between 1.5 to 4.10.9 nm. The effect ofconcentration of cadmium and TGA has been investigated to explain the growthkinetics and stabilization of CdS quantum dots. Structural and morphologicalstudies carried out by X-ray diffraction (XRD), Transmission electronmicroscopy (TEM), and Scanning electron microscopy (SEM). Optical propertieshave been studied by UV-visible spectroscopy, Fluorescence measurements, andFTIR analysis. FTIR study suggested the thiolated interaction between CdS andthioglycolic acid. The electronic band gap was found to increase up to 3.93 eVfrom bulk 2.42 eV. The effect of cationic and anionic surfactants onstabilization of TGA capped CdS quantum dots have been studied. The first ordergrowth kinetic was observed and kobs 5.78x 10-4 s-1was obtained in optimized condition.