EuS nanocrystals: a novel synthesis for the generation of monodisperse nanocrystals with size-dependent optical properties.

A novel one-step solvothermal synthesis of stable colloidal EuS nanocrystals (NCs) is reported. The EuS NCs were synthesized in oleylamine directly from europium oleate and diethylammonium diethyldithiocarbamate in the presence of dodecanethiol and phenanthroline. The formation of single crystalline monodisperse EuS NCs, with sizes finely controlled by synthetic conditions, was confirmed by x-ray diffraction and high resolution transmission electron microscopy analysis. The exciton transition of EuS NCs blue-shifts to higher energies with decreasing particle sizes, as revealed by optical absorption and photoluminescence measurements. The feasibility of synthesizing monocrystalline EuS nanorods by solvothermal synthesis was also demonstrated, making them potentially viable materials for device applications.