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Department of Physics

Staff profile

Publication details for Professor Andy Monkman

Rothe, C & Monkman, A (2002). Dynamics and trap-depth distribution of triplet excited states in thin films of the light-emitting polymer poly (9,9-di(ethylhexyl)fluorene). Physical Review B 65(7): 4.
  • Publication type: Journal papers: academic
  • ISSN/ISBN: 1098-0121
  • Keywords: PI-CONJUGATED POLYMERS; PHOSPHORESCENCE; EXCITATIONS; DIODES

Author(s) from Durham

Abstract

We study the behavior of the phosphorescence and delayed fluorescence
of the light-emitting polymer poly[9,9-di(ethylhexyl)fluorene] with
different excitation intensities at low temperatures. The results
indicate a limited number of potentially occupied energy sites (traps)
for triplet-excited states. From analysis of temperature-dependent
intensity measurements, we demonstrate the Gaussian distribution of
these energy traps and determine an average trap depth of 4.4 +/- 0.1
meV combined with a half-width of 4.5 +/- 0.3 meV. We also observe a
redshift of the phosphorescence spectrum with increasing temperature,
but no concomitant spectral narrowing.