Solvent and concentration effects on fluorescence emission in MEH-PPV solution

Interplay among electronic characteristics, morphology and device efficiency in three fluorene alternated copolymers

“…That could be ascribed to the progressive removal of the solvent which will suppress low-energy rotations and vibrations along the backbone of the polymer chain, thus increasing its conjugation length [20,21]. The same trend is found for P(FTh) [22][23][24][25]. There is plenty of literature data showing that interchain interaction in conjugated polymers can modify substantially the exciton energy [22].…”

Study of solvent-conjugated polymer interactions by polarized spectroscopy: MEH–PPV and Poly(9,9′-dioctylfluorene-2,7-diyl)

“…There is a gradual change in the spectra that is in contrast with sharp differences observed in the molecular orientation when isolated polymer chains are deposited on glass from dichloromethane or toluene solutions [67]. This difference is easily explained by the effect of chain interactions in compact polymer films compared to isolated molecules.…”

“…The traditional interpretation of solvent shift produced by dispersion interactions is that they shift the energy of electronic states involved in the transitions. In this case, polymer-solvent interactions also change the effective conjugation length [65,67], and thus enhance the energy of the electronic transition.…”

“…This difference is easily explained by the effect of chain interactions in compact polymer films compared to isolated molecules. The different spectral distribution displayed in emission can be explained by heterogeneity in chain conformation in solution, which is transferred to the films [65,67].…”

Synthesis of novel phenylenevinylene linkers with electron-donating substituents by the Heck reaction

“…2). According to literature reports [20,21], OPVs usually exhibit a single dominant absorption band in the UV region of 320-400 nm, with a small shoulder at shorter wavelengths, as seen for OPVÀ ÀH (1). This differs from the spectra of the other OPVs, which exhibit two distinct bands.…”