Synthesis, characterization and optical properties of CdSe/CdS and CdSe/ZnS core-shell nanoparticles

Controlled organic synthesis method used for the preparation of cadmium selenide (CdSe) quantum dots, which are covered with cadmium sulfide (CdS) and zinc sulfide (ZnS) using TOP mediated has been presented in this paper. The size, shape, internal structure, chemical composition and functional groups of the core-shell nanoparticles were analyzed using X-ray diffraction, transmission electron microscopy, high resolution transmission electron microscopy, energy dispersive spectra and FTIR. These studies show that the particle size is in 2-10 nm range with hexagonal phase. The optical properties were analyzed through UV-visible spectroscopy, photoluminescence spectroscopy and micro-Raman spectroscopy. Photoluminescence blue shift and broadening of Raman spectrum further confirm the narrow size of particles.