Facile capping CdS and ZnS shells by thermolysis of ethylxanthate precursors for CdSe/CdS/ZnS nanocrystals

We described the tunable CdS and ZnS shells by facile thermolysis of air-stable cadmium ethylxanthate (Cd(ex)2) and zinc ethylxanthate (Zn(ex)2) precursors for CdSe/CdS/ZnS core/shell nanocrystals (CCZ NCs). The use of Cd(ex)2 and Zn(ex)2 offered adjustable capping reaction temperature ranging from 175 °C to 255 °C for various CdSe core sizes and CdS/ZnS shell thicknesses in CCZ NCs. Injection procedures of Cd(ex)2 and Zn(ex)2 precursors were flexible and optional within several seconds to tens of minutes for the capping process. All these revealed a feasible route to coat CdS and ZnS shells on nanocrystals for manipulating the structure, surface and optical characterizations.