Heterocyclic dithiocarbamates: precursors for shape controlled growth of CdS nanoparticles

We report the synthesis of hexadecylamine (HDA) and tri-n-octylphosphine oxide (TOPO) capped CdS nanoparticles using cadmium piperidine dithiocarbamate (DTC) and cadmium tetrahydroquinoline dithiocarbamate complexes as single source precursors. These complexes are easy to prepare, air stable for long periods and pyrolyze to give high quality nanoparticles. The nanoparticles obtained showed quantum confinement with near band edge luminescence. The reaction conditions such as the amount of capping group and reaction temperature were varied to study their influence on the properties and morphology of the nanoparticles. Elongated CdS particles in the form of rods, bipods and tripods were obtained for the HDA capped CdS whereas spherical particles were observed when TOPO was used as the capping material. The X-ray diffraction studies revealed the hexagonal phase to be dominant. Details on the particle crystallinity, size and size distribution were investigated by transmission electron microscopy (TEM) and high resolution TEM.