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CPP: Chemische Physik und Polymerphysik

CPP 13: Dünne Polymerfilme

CPP 13.5: Talk

Thursday, March 27, 2003, 11:15–11:30, ZEU/118

Spectral Properties and Light-Induced Processes in Heterogeneous Nanocomposites Based on CdSe Semiconductor Nanocrystals and Porphyrins — •Eugene Petrov^1,2, Christian von Borczyskowski¹, Edward Zenkevich², Alexander Shulga², Frank Cichos¹, and Sergej Gaponenko² — ¹Institut für Physik 122501, TU Chemnitz, 09107 Chemnitz — ²Institute of Molecular and Atomic Physics and B.I. Stepanov Institute of Physics National Academy of Sciences, 70 F. Skaryna Avenue, 220072 Minsk, Belarus

In the present report, we discuss optical and photophysical properties of heterosupramolecular nanosize arrays based on CdSe/ZnS core/shell NCs (with controlled CdSe radius and number of ZnS layers) and a variety of pyridyl containing porphyrin molecules (P) attached to a particle surface via non-covalent ligation interactions. The formation of the NC/porphyrin supramolecular heterostructures (well soluble in toluene and chloroform) takes place due to a ligand interactions of Zn atoms of outer ZnS shell with pyridyl containing porphyrin molecules, like upon the formation of self-assembled multiporphyrin arrays. The formation of the complexes is accompanied by strong luminescence quenching of the NC while fluorescence parameters for porphyrin ligands remain practically unchanged. The possible mechanisms of the non-radiative relaxation processes in CdSe/ZnS nanocrystals passivated with meso-pyridyl substituted porphyrins having (smaller ΔE=LUMO-HOMO energy gap with respect to that for NCs) will be analyzed (electron/hole tunneling, the realization of effective non-radiative decay pathways caused by the formation of interfacial electronic states in NC/P heterostructures, etc.).