Transient electroluminescence spectroscopy of polyfluorene light-emitting diodes

We present transient electroluminescence spectra of polyfluorene light-emitting diodes. The luminescence spectra recorded after switch-off of a 5 V driving pulse exhibit a dynamic change with time. A study of the temperature and bias offset dependence reveals that charge carriers are preferentially trapped on low energy oxidative sites present on the polyfluorene backbone. These observations of the charge carrier dynamics in light-emitting diodes (LEDs) compare to recent results on exciton trapping on emissive intra-chain defects in polyfluorenes. (C) 2003 Elsevier Science B.V. All rights reserved.