A possible possiblity of this difference can be linked to the
existence of the charge separating interface in ZnSe/CdS type-II semiconductor, which
increases the spatial separation of charges [33, 46], leading to reducing the overlap of
electrons and holes and decreasing the recombination of carriers in these nanoparticles. Ning
et al., have shown that trapping of photo - induced holes on CdS QDs can provide a similar
type of hole localization as does the ZnSe domain in ZnSe/CdS nanocrystals [47]