Combined electroluminescence and charge profile measurements in polyethylene naphthalate

Under DC stress, electroluminescence in polyethylene naphthalate films is stable, current-proportional, above a threshold field of 150 kV/mm. At this field level, the luminescence is thought to be triggered by impact excitation and/or ionization of the luminescent centers by hot electrons, or, alternatively, by electron and hole injection, migration and recombination. Investigation of the internal space charge distribution versus field is believed to constitute a relevant approach to discuss the excitation process.