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Suppression of secondary PL emission by indirect photoexcitation
Author(s) -
Byun H.Y.,
Chung I.J.,
Suh Y.S.,
Shim H.K.,
Kim D.Y.,
Kim C.Y.
Publication year - 2003
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200390024
Subject(s) - photoexcitation , polyfluorene , chromophore , photoluminescence , materials science , photochemistry , excited state , energy transfer , absorption (acoustics) , emission intensity , optoelectronics , atomic physics , electroluminescence , chemistry , molecular physics , nanotechnology , physics , layer (electronics) , composite material
A blend of a newly synthesized polyfluorene(PDHBF) and polyvinylcarbazole(PVK) exhibits a photoluminescence(PL) emission spectrum of PDHBF without an increase in the PL intensity on photoexcitation at 340 nm, the UV‐visible absorption maximum of PVK, despite of a substantial spectrum overlap. However, the indirect photoexcitation of the blend suppresses the secondary emission of the PL with the maximum at 520 nm. The chromophores generating the secondary emission are formed when the chromophores are photoexcited above the critical energy level of an excited state. The chromophores formed by the energy transfer have energy lower than the critical energy and fail to form the excimers. A low temperature PL study of the blend in a cryogenic chamber proves that the energy transfer in the system takes place mainly between the excimers of PVK generated by the partially eclipsed dimeric states of two carbazole units and the fluorophores of PDHBF.