Abstract

We investigated the excitation density dependence of the photoluminescence spectra of hybrid poly(9,9-dioctylfluorene)-CdSe/ZnS nanocrystals (PF8-NCs) thin films. We demonstrate that this experiment allows the determination of the efficiency of all the CdSe/ZnS NCs excitation processes and that the presence of amplified spontaneous emission (ASE) from the PF8 leads to a strong dependence of the NC excitation processes from the laser excitation density. Below the PF8 ASE threshold only about 6% of the excitons in the NCs are due to pump laser absorption, while about 94% of the NC excitation is due to the interaction with the PF8, and it is due for about 58% to PF8→NC Frster resonant energy transfer (FRET) and for about 37% to reabsorption by the NCs of the PF8 luminescence. The presence of PF8 ASE significantly modifies this scenario by strongly decreasing the FRET importance and strongly increasing the reabsorption one. The interplay between reduced FRET and increased reabsorption overall decreases the NC excitation due to PF8 indicating that ASE from the donors should be avoided if efficient NCs excitation under strong pumping is wished

Autore Pugliese

• Anni Marco

Tutti gli autori

• M. Anni , E. Alemanno , A. Cretì , C. Ingrosso , A. Panniello , M. Striccoli , M. L. Curri , M. Lomascolo

Titolo volume/Rivista

JOURNAL OF PHYSICAL CHEMISTRY. A, MOLECULES, SPECTROSCOPY, KINETICS, ENVIRONMENT, & GENERAL THEORY

Anno di pubblicazione

2010

ISSN

1089-5639

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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