Cadmium Telluride Quantum Dots--Versatile Contrivance to Study the Minutiae of Size Dependent Optical Properties of Thiol Capping

摘要

This article mainly demonstrates the viability to produce highly luminescent thiol capped cadmium telluride quantum dots in an aqueous phase containing 3-mercaptopropionic acid as a stabilizing cum capping agent. The size dependent and optical properties of cadmium telluride quantum dots were obtained through ultraviolet-visible (UV-Vis), photoluminescence and time resolved fluorescence spectroscopic techniques. The small grain size of quantum dots in cubic phase was observed in X-ray diffraction analysis. The decrease in particle size of the same with increase in band gap is also found from UV-Vis spectroscopy and X-ray diffraction (XRD) studies. The same has been confirmed by high resolution transmission electron microscope (HR-TEM), which shows the morphology and size distribution of the quantum dots. They are spherical in shape and relatively uniform with diameter of 5 nm approximately. The luminescent properties of the quantum dots were investigated using fluorescence spectrophotometry. The formation of cadmium telluride quantum dots upon interaction of thiol group was confirmed by Fourier transform infrared spectra (FT-IR).