Optical characterization of ZnSe/CdSe nanocrystals with π-conjugated organic ligands

Organic-inorganic hybrid systems having the excitation resonance state are predicted to exhibit unique optical properties owing to a new type of excitons, i.e., hybrid excitons. The formation of the hybrid excitons requires the resonance between the excited states in organic and inorganic parts and the strong interactions with each other. In this study, we synthesized an organic-inorganic hybrid system (ZnSe/CdSe-2-aminoanthracene (AAn)) in order to realize the excitation resonance state. For the ZnSe/CdSe-AAn system in which PL wavelengths of the organic and inorganic parts are almost the same, the PL peak shifts by ∼20 nm toward longer wavelength and the decay time constant decrease with the addition of AAn. These changes in the hybrid cannot be explained simply in terms of self-absorption or excitation energy transfer. These results strongly suggest that a new excited states or new decay route was formed by the resonance of the excited states.