Preparation and electroluminescence of ZnO/CdS composite particles

ZnO precursor was prepared by a sol-gel technique and the CdS/ZnO composite particles was obtained by hydrothermal reaction. The nanocrystals were characterized by infrared spectrum (IR), X-ray diffraction (XRD) and scanning electron microscope (SEM), which were used to characterized their structure, composition and morphology. The optical properties were investigated by electroluminescence spectra. It is found that CdS nanoparticles were grown on the surface of ZnO. EL spectra indicate that CdS/ZnO composite particles without calcining presents the exciton emission of CdS and the intensity of EL increases obviously. While the CdS/ZnO composite particles after calcining presents the defect emission of ZnO as well as the full width at half maximum (FWHM) becomes narrow.