Optical properties of stable, strongly confined CdS nanostructures prepared by microwave assisted synthesis

Abstract

Strongly confined CdS nanostructures are formed by a microwave-assisted chemical route of synthesis. The mean particle size is found to be around 1 nm. The nanostructures are obtained in the form of either powders or suspensions in appropriate solvents by different chemical treatments. The nanostructures are found to be quite stable. Optical absorption spectra exhibit clear and large blue-shifts from the bulk spectrum depending on the particle size. The experimental data are analysed by fitting them to theoretical models. Room temperature absorption spectra show structures attributed to exciton transitions. The corresponding excitation spectra reveal exciton transitions. Results on the nonlinear optical response using the z scan technique suggest large optical nonlinearity in the nanostructures.