We report the results of steady-state photoinduced absorption experiments on PDA-4BCMU grown on silica substrate. We observe three photoinduced absorption bands at 0.82, 0.95, and 1.39 eV whose relaxation dynamics are identical for the two low-energy peaks but different for the 1.39-eV band. On the basis of the spectra, the pump intensity, modulation frequency, and signal phase dependences we conclude that the 0.82 and 0.95-eV absorption features are due to charged states while the 1.39-eV peak is originated by triplet excitons. The photogeneration of both charged and neutral states in PDA-4BCMU as previously observed in polycarbazolyldiacetylenes indicates that this is a general feature of polydiacetylenes. The relative weight of one excited species over the other one is influenced by the molecular and supramolecular organization of the polymer.

LONG-LIVED PHOTOEXCITED STATES IN POLYDIACETYLENES: THE PHOTOINDUCED-ABSORPTION SPECTRA OF PDA-4BCMU

COMORETTO, DAVIDE;CUNIBERTI, CARLA EMILIA;MUSSO, GIANFRANCO;DELLEPIANE, GIOVANNA;
1998-01-01

Abstract

We report the results of steady-state photoinduced absorption experiments on PDA-4BCMU grown on silica substrate. We observe three photoinduced absorption bands at 0.82, 0.95, and 1.39 eV whose relaxation dynamics are identical for the two low-energy peaks but different for the 1.39-eV band. On the basis of the spectra, the pump intensity, modulation frequency, and signal phase dependences we conclude that the 0.82 and 0.95-eV absorption features are due to charged states while the 1.39-eV peak is originated by triplet excitons. The photogeneration of both charged and neutral states in PDA-4BCMU as previously observed in polycarbazolyldiacetylenes indicates that this is a general feature of polydiacetylenes. The relative weight of one excited species over the other one is influenced by the molecular and supramolecular organization of the polymer.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/303181
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 18
  • ???jsp.display-item.citation.isi??? 20
social impact