An Alternative of CdSe Nanocrystal Emitters:  Pure and Tunable Impurity Emissions in ZnSe Nanocrystals

The concept, decoupling doping from nucleation and/or growth, allows us to dope nearly all nanocrystals in a given sample which is indicated by complete quenching of the host emission and bright emission from the dopants at characteristic wavelengths tunable in most parts of the visible window using a ZnSe host. In an extreme case, ZnSe coated MnSe nanocrystals (MnSe:ZnSe) emit similarly as commonly known doped nanocrystals. In comparison with CdSe nanocrystals, these alternative emitters not only are intrinsically less toxic but also show some unexpected and expected advantages: stable against thermal and environmental changes, zero reabsorption, and no Forster energy transfer. In addition to their applications to replace CdSe based nanocrystal emitters, the unique structure and properties of the doped nanocrystals are of interest for studying fundamental issues in the field.