LAUSR

Abstract In this study, we analyzed the effect of the composition and thickness of shell material on morphology, structure and optical properties of ultrathin CdSe/CdS, CdSe/CdS/ZnS and CdSe/ZnS core-shell nanoplatelets. It is shown that the growth of CdS and ZnS shells on ultrathin CdSe nanoplatelets with excitonic absorption at 463 nm leads to the formation of flat CdSe/CdS and CdSe/CdS/ZnS and folded CdSe/ZnS core-shell heterostructures, respectively. The tuning of the first excitonic transition in a range of 510–635 nm is shown by changing the composition and thickness of the shell material. Despite large lateral sizes, the CdSe/CdS and CdSe/CdS/ZnS core-shell nanoplatelets showed narrow emission bands with about 18–21 nm width. Emission width of the CdSe/ZnS heterostructures is shown to be thickness dependent and broader than that of CdSe/CdS and CdSe/CdS/ZnS heterostructures. Such control of the electronic structure of 2D core-shell nanoparticles, simply by changing the thickness and composition of the shell material may be attractive for the light-emitting device technology and lasers.