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BY-NC-ND 3.0 license Open Access Published by De Gruyter Open Access December 1, 2007

Energy up-conversion in dilute polyfluorene solutions

Alexander Kuehne, Allan Mackintosh, David Armstrong and Richard Pethrick
From the journal Open Chemistry


Poly(9,9-dioctylfluorene) (PFO) shows highly efficient blue emission with photo excitation occurring between 340–400 nm. Here we show that PFO can in dilute solution emit at a wavelength well below that at which it is being exited. This, we propose is related to an energy transfer from conjugated parts of the polymer chain into more localised states which then emit at a lower wavelength. These localised states can be considered as defects in the conjugation of the polymer or as chain ends. These may produce quasi monomer or quasi dimer species within the chain, which will have a HOMO-LUMO gap of higher energy than the conjugated polymer. These then fluoresce at the lower wavelength; essentially causing, by energy transfer, a process of energy up-conversion.

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Published Online: 2007-12-1
Published in Print: 2007-12-1

© 2007 Versita Warsaw

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

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