Air-stable single-source precursors for the synthesis of chalcogenide semiconductor nanoparticles

Bis(hexylmethyldithio-/diselenocarbamato)cadmium(II)/zinc(II) (M(E2CNMenHex)2 [M = Zn, Cd; E = S, Se]) have been used as single-source precursors for the preparation of TOPO-capped CdS, CdSe, ZnS, and ZnSe nanoparticles. The precursors are stable for long periods of time and pyrolyse cleanly to give high yields of nanocrystals. The nanoparticles were of high quality, close to monodispersed, and showed quantum confinement with characteristic close to band edge luminescence in their emission spectra. The broad diffraction in the XRD pattern and diffuse diffraction rings of the SAED pattern are typical of nanometric size particles. The TEM micrographs showed well-defined, close to spherical particles and the lattice fringes in the HRTEM images confirmed the crystalline nature. The presence of a strong phosphorus peak in the EDAX spectra is indicative of TOPO or TOPE (E = S or Se) bound to the surface.