Fabrication and optical characterization of CdSe nanoparticles liganded with π-conjugated organic molecules of Rhodamine dyes

Abstract

The resonant state between Frenkel excitons in the organic molecules and Wannier excitons in the inorganic semiconductor are predicted to lead to a new type of exciton which exhibits unique optical properties. To achieve the resonance states, strong interaction of excited states between the organic molecules and the inorganic semiconductor is necessary. In this study, we synthesized inorganic nanocrystals liganded with π-conjugated organic ligands (CdSe–Rhodamine). The emission wavelengths of the CdSe nanocrystals are tuned to those of the Rhodamine molecules. In the CdSe nanocrystals–Rhodamine B complex, the significant change was observed in the PL decay behavior. The relative intensity of the fast decay component was significantly enhanced with the addition of Rhodamine B to the CdSe solution while the decay–time constant of the fast decay time component became very close to that of Rhodamine B. The results strongly suggest that the radiative rate was significantly enhanced in the hybrid system.