Suppression of the keto-emission in polyfluorene light-emitting diodes: Experiments and models

Xiao Hui Yang*, Frank Jaiser, Dieter Neher, Padreyia V. Lawson, Jean Luc Brédas, Egbert Zojer, Roland Güntner, Patricia Scanduicci De Freitas, Michael Forster, Ulli Scherf

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

57 Scopus citations


The spectral characteristics of polyfluorene (PF)-based light-emitting diodes (LEDs) containing a defined low concentration of either keto-defects or of the polymer poly(9,9-octylfluorene-co-benzothiadiazole) (F8BT) are presented. Both types of blend layers were tested in different device configurations with respect to the relative and absolute intensities of green and blue emission components. It is shown that blending hole-transporting molecules into the emission layer at low concentration or incorporation of a suitable hole-transporting layer reduces the green emission contribution in the electroluminescence (EL) spectrum of the PF:F8BT blend, which is similar to what is observed for the keto-containing PF layer. We conclude that the keto-defects in PF homopolymer layers mainly constitute weakly emissive electron traps, in agreement with the results of quantum-mechanical calculations.

Original languageEnglish (US)
Pages (from-to)1097-1104
Number of pages8
JournalAdvanced Functional Materials
Issue number11
StatePublished - Nov 2004
Externally publishedYes

ASJC Scopus subject areas

  • General Chemistry
  • Condensed Matter Physics
  • General Materials Science


Dive into the research topics of 'Suppression of the keto-emission in polyfluorene light-emitting diodes: Experiments and models'. Together they form a unique fingerprint.

Cite this