Optical properties of core/multishell CdSe/Zn(S,Se) nanocrystals

CdSe nanocrystals are now known as highly efficient fluorescent light sources. Their efficiency is however strongly dependent on the quality of the passivation layers. We show here that using a ZnSe/ZnS bi-layer shell leads to a larger photoluminescence yield than both ZnSe and ZnS simple shells. The intermediate ZnSe layer acts as a lattice parameter adaptation layer to improve on the core/shell interface quality, while the ZnS outer shell maximizes the exciton confinement.