Synthesis and characterization of ZnSe/ZnS core/shell nanocrystals by aqueous reflux route

Highlights: → ZnSe/ZnS core/shell nanocrystals (NCs) with strong photoluminescence (PL) intensity and improved photochemical stability are synthesized through a simple water bath reflux route. → The photoluminescence of ZnSe/ZnS core/shell NCs is also remarkably improved, which can be approved by the PL spectrum and laser-scanning confocal microscope test. → The shell is constitutive of crystalline and amorphous ZnS NC film. - Abstract: ZnSe/ZnS core/shell nanocrystals (NCs) with strong photoluminescence (PL) intensity and improved photochemical stability are synthesized through a simple water bath reflux route. Diffraction peaks can be indexed by zinc blend structure of ZnSe and ZnS. Transmission electron microscope (TEM) images reveal that each ZnSe NC (27 nm) is coated by a ZnS epitaxial shell. The ZnS shells are constitutive of crystalline and amorphous ZnS NC film with average thickness of 5 nm thick. The photoluminescence of ZnSe/ZnS core/shell NCs is also remarkably improved, which can be approved by the PL spectrum and laser-scanning confocal microscope test.