The relation between electrically active defects in organic and polymeric semiconductor materials and degradation of devices such as loss of luminance is currently not understood. In this paper, we study defect related charge processes using electrical transients in polymeric and organic diodes. We monitor slow charging and discharging currents as a function of time for both virgin and electrically aged devices. The current transients are analyzed spectroscopically in time domain using a technique called Time Analyzed Transient Spectroscopy, which is similar to DLTS in its implementation. We observe highly stretched exponentials over 3-4 orders of magnitude in time up to thousands of seconds indicating existence of large distribution in time constants in aged PLED devices. We demonstrate ability to distinguish between different mechanisms of charge storage related to defect related processes in typical OLED and PLED. © 2005 Materials Research Society.