Tracking of conduction phenomena and degradation in organic light emittingdiodes by current noise measurements

Noise current analysis, both in time and frequency, is proposed as a means to sense variations of the microscopic conduction in organic light emitting diodes and to track their time evolution. The sensitivity of the technique would allow to correlate the carriers conduction properties with the corre sponding changes in the microscopic morphology of the organic layers as obt ained with structural or spectroscopic investigations. The method is shown to be very effective also in sensing the initial state and the growth of or ganic diodes catastrophic degradation in large advance to current monitorin g or other techniques. (C) 2001 American Institute of Physics.