SYNTHESIS AND CHARACTERIZATION OF UNCAPPED AND CAPPED ZINC SULFIDE (ZnS) QUANTUM DOTS

Abstract

Zinc sulfide (ZnS) quantum dots have been synthesized via chemical route. The results of uncapped and poly-vinyl alcohol capped ZnS quantum dots (QDs) are compared. X-ray diffraction (XRD) shows synthesized ZnS QDs are in cubic phase (zinc blende). Effect of poly-vinyl alcohol concentration on synthesized ZnS QDs is significant. The crystalline size of uncapped and poly-vinyl alcohol capped ZnS QDs are 2.4 nm and 1.8 nm respectively. Photoluminescence spectrum of poly-vinyl alcohol capped ZnS QDs is blue shifted in comparison to uncapped QDs. The emission peaks are obtained at 433 nm and 425 nm for uncapped and poly-vinyl alcohol capped ZnS QDs respectively. Poly-vinyl alcohol has affected the particle growth because particle size changes with the concentration of poly-vinyl alcohol.