Degradation kinetics of the spectral emission in polyfluorene light-emitting electro-chemical cells and diodes

¹ Laboratoire de Spectrométrie Physique, Université Joseph Fourier, Grenoble 1 and CNRS UMR C5588, 140 rue de la physique, BP 87, 38042, Saint-Martin d'Hères Cedex, France
² Laboratoire International sur les Matériaux Électroactifs, CNRS, UMR 2289, Université de Montréal, CP 6128, Montréal QC H3C 3J7, Canada

Corresponding author: ouisse@spectro.ujf-grenoble.fr

Received: 21 March 2003
Revised: 4 July 2003
Accepted: 10 July 2003
Published online: 16 September 2003

Abstract

We have studied the well known spectral shift of polyfluorene blue light emitters, using either electrochemical cells or conventional organic light emitting diodes. From the recording of the electroluminescence spectra as a function of “stress” time, we conclude that the degradation mainly depends on the number of electrons which have passed through the conducting polymer, rather than on the hole current magnitude or the dissipated power.