SYNTHESIS AND CHARACTERIZATION OF CdSe/ZnO CORE/SHELL NANOCRYSTALS

Highly luminescent monodispersed CdSe nanocrystals were prepared from CdO and Se powder in a three-component hexadecylamine-trioctylphosphine oxide-trioctylphosphine (HAD-TOPO-TOP) mixture under high temperature and nitrogen protection. CdSe/ZnO core/shell nanocrystals were produced by adding Zn(Ac)2 and LiOH into CdSe nanocrystals solution under ultrasonic at low temperature. ZnO shell grows heterogeneously on the CdSe substrate. The structure and fluorescence have been characterized by TEM (transmission electron micrograph), XRD (X-ray diffraction), UV-Vis and PL spectra. It can be found that after the surface passivation with ZnO shell, electrons were confined in the CdSe core due to the wide band-gap effect of ZnO, which resulted in the obvious increasing of the fluorescent intensity.