title: Enhancing the photoluminescence emission of conjugated MEH-PPV by light processing.
abstract: We show here that treatment of thin films of conjugated polymers by illumination with light leads to an increase of the intensity of their photoluminescence by up to 42%. The corresponding enhancement of absorbance was much less pronounced. We explain this significant enhancement of photoluminescence by a planarization of the conjugated polymer chains induced by photoexcitations even below the glass transition temperature, possibly due to an increased conjugation length. Interestingly, the photoluminescence remains at the enhanced level for more than 71 h after treatment of the films by illumination with light, likely due to the fact that below the glass transition temperature no restoring force could return the conjugated chains into their initial conformational state.
authors.affiliation: Freiburg Institute for Advanced Studies , Albertstraße 19, Freiburg 79104, Germany.
authors.forename: Ioan
authors.initials: I
authors.lastname: Botiz
authors.forename: Paul
authors.initials: P
authors.lastname: Freyberg
authors.forename: Cosmin
authors.initials: C
authors.lastname: Leordean
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Gabudean
authors.forename: Simion
authors.initials: S
authors.lastname: Astilean
authors.forename: Arnold Chang-Mou
authors.initials: AC
authors.lastname: Yang
authors.forename: Natalie
authors.initials: N
authors.lastname: Stingelin