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.

Graphical abstractFlexible manipulations on CdS layers and subsequent ZnS layers coated on CdSe nanocrystals for CdSe/CdS/ZnS core/shell nanocrystals by thermolysis of air-stable cadmium ethylxanthate and zinc ethylxanthate precursors.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The thermolysis of cadmium ethylxanthate and zinc ethylxanthate precursors brought a facile and feasible capping of CdS and ZnS shells on CdSe nanocrystals. ► The reaction temperature down to 175 oC and the optional injection procedure made the capping processes more flexible for coating CdS and ZnS shells on CdSe nanocrystals. ► All these and the PL blue-shift provided more facile alternatives for tuning and exploring CdSe/CdS/ZnS nanocrystals with adjustable shells and cores.