Preparation And Properties Of ZnS Composite Semiconductor Nanoparticles

Nanometer ZnS is extensively applied in the fields of electronic, photocatalytic and photoelectric materials because of its unique structure and property. But some limitation and defection on ZnS itself hinder its application.Core/shell structure ZnS/CdS composite semiconductor nanoparticles were synthesized by using an ion exchange reaction in microemulsion for the first time in this paper. The better experimental conditions were obtained. And the simple synthesization of core/shell structure ZnS/CdS composite semiconductor nanoparticles was achieved. The optical properties were characterized by UV absorption spectra and PL spectra in order to probe into the experimental elements and affect law of ZnS/CdS composite semiconductor nanoparticles. It can provide the important theoretical reference and practical experience to synthesize this type material in future. After many probing trials, the final experimental results were set: the best suitable growing temperature of ZnS crystal is 35°C, the exchanging temperature of the ion exchange reaction synthesized ZnS/CdS is 60°C, the exchanging time is 120min, and Cd/Zn ratio is 1.0.The result indicated ZnS/CdS composite semiconductor nanoparticles' absorption wavelength occured the red shift, their luminant properties were also increased greatly by comparing with the optical properties of pure ZnS, CdS nanoparticles and ZnCdS mixture with UV absorption spectra and PL spectra. And the achievement of core/shell structure was proved firstly. The samples were presented further by AFM and TEM. The results indicated that ZnS/CdS composite nanoparticles had core/shell structure , and their surface was smooth, globular. The average diameter of ZnS/CdS composite nanoparticles was about 80nm.The method of synthesizing core/shell structure ZnS/CdS composite nanoparticles in this paper was reasonable, simple and controlled easily. In the field of synthesization of these nanometer particles, it had its own unique advantages, and opened up a new way to prepare similar material. If the experimental condition is controlled very well, the core/shell structure ZnS/CdS will be realized certainly, and its absorption spectra will occur the red shift so that the scope used in the fields of electronic, photocatalytic and photoelectric materials is extended.