ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The time-resolved spectroscopy in polydiacetylene single crystals (PDA-MADF {poly-1-[3-(methylamino)phenyl]-4-[3,5-bis(trifluoromethyl)phenyl]-1, 3-butadiyne}) on femtosecond and picosecond time scales was performed. The time dependence of the photoinduced reflectance change in PDA-MADF exhibits three components with lifetimes ∼200 fs, 1–2 ps, and (very-much-greater-than)200 ps. These components are assigned to the free 1Bu excitons, self-trapped excitons, and triplet excitons. From the excitation intensity dependence of the reflectance change, a significant role of bimolecular interactions between singlet excitons for the formation of triplet excitons is clarified. A model of the mechanism of triplet exciton formation after the creation of singlet excitons is proposed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.465721
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